* [PATCH 3/5] Documentation/landlock: Fix missing case for ABI 6 in downgrade example
From: Tingmao Wang @ 2025-12-28 1:27 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, linux-security-module
In-Reply-To: <cover.1766885035.git.m@maowtm.org>
Note that this code is different from the one in sandboxer.c since
sandboxer won't ever add LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF and
LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF.
Fixes: 12bfcda73ac2 ("landlock: Add LANDLOCK_RESTRICT_SELF_LOG_*_EXEC_* flags")
Signed-off-by: Tingmao Wang <m@maowtm.org>
---
Documentation/userspace-api/landlock.rst | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst
index 1d0c2c15c22e..903d2ad11852 100644
--- a/Documentation/userspace-api/landlock.rst
+++ b/Documentation/userspace-api/landlock.rst
@@ -127,6 +127,12 @@ version, and only use the available subset of access rights:
/* Removes LANDLOCK_SCOPE_* for ABI < 6 */
ruleset_attr.scoped &= ~(LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
LANDLOCK_SCOPE_SIGNAL);
+ __attribute__((fallthrough));
+ case 6:
+ /* Removes LANDLOCK_RESTRICT_SELF_LOG_* for ABI < 7 */
+ supported_restrict_flags &= ~(LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON |
+ LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF |
+ LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF);
}
This enables the creation of an inclusive ruleset that will contain our rules.
--
2.52.0
^ permalink raw reply related
* [PATCH 4/5] selftests/landlock: Use scoped_base_variants.h for ptrace_test
From: Tingmao Wang @ 2025-12-28 1:27 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, linux-security-module,
Tahera Fahimi
In-Reply-To: <cover.1766885035.git.m@maowtm.org>
ptrace_test.c currently contains a duplicated version of the
scoped_domains fixture variants. This patch removes that and make it use
the shared scoped_base_variants.h instead, like in
scoped_abstract_unix_test and scoped_signal_test.
This required renaming the hierarchy fixture to scoped_domains, but the
test is otherwise the same.
Cc: Tahera Fahimi <fahimitahera@gmail.com>
Signed-off-by: Tingmao Wang <m@maowtm.org>
---
.../testing/selftests/landlock/ptrace_test.c | 154 +-----------------
.../selftests/landlock/scoped_base_variants.h | 9 +-
2 files changed, 12 insertions(+), 151 deletions(-)
diff --git a/tools/testing/selftests/landlock/ptrace_test.c b/tools/testing/selftests/landlock/ptrace_test.c
index 4e356334ecb7..4f64c90583cd 100644
--- a/tools/testing/selftests/landlock/ptrace_test.c
+++ b/tools/testing/selftests/landlock/ptrace_test.c
@@ -86,16 +86,9 @@ static int get_yama_ptrace_scope(void)
}
/* clang-format off */
-FIXTURE(hierarchy) {};
+FIXTURE(scoped_domains) {};
/* clang-format on */
-FIXTURE_VARIANT(hierarchy)
-{
- const bool domain_both;
- const bool domain_parent;
- const bool domain_child;
-};
-
/*
* Test multiple tracing combinations between a parent process P1 and a child
* process P2.
@@ -104,155 +97,18 @@ FIXTURE_VARIANT(hierarchy)
* restriction is enforced in addition to any Landlock check, which means that
* all P2 requests to trace P1 would be denied.
*/
+#include "scoped_base_variants.h"
-/*
- * No domain
- *
- * P1-. P1 -> P2 : allow
- * \ P2 -> P1 : allow
- * 'P2
- */
-/* clang-format off */
-FIXTURE_VARIANT_ADD(hierarchy, allow_without_domain) {
- /* clang-format on */
- .domain_both = false,
- .domain_parent = false,
- .domain_child = false,
-};
-
-/*
- * Child domain
- *
- * P1--. P1 -> P2 : allow
- * \ P2 -> P1 : deny
- * .'-----.
- * | P2 |
- * '------'
- */
-/* clang-format off */
-FIXTURE_VARIANT_ADD(hierarchy, allow_with_one_domain) {
- /* clang-format on */
- .domain_both = false,
- .domain_parent = false,
- .domain_child = true,
-};
-
-/*
- * Parent domain
- * .------.
- * | P1 --. P1 -> P2 : deny
- * '------' \ P2 -> P1 : allow
- * '
- * P2
- */
-/* clang-format off */
-FIXTURE_VARIANT_ADD(hierarchy, deny_with_parent_domain) {
- /* clang-format on */
- .domain_both = false,
- .domain_parent = true,
- .domain_child = false,
-};
-
-/*
- * Parent + child domain (siblings)
- * .------.
- * | P1 ---. P1 -> P2 : deny
- * '------' \ P2 -> P1 : deny
- * .---'--.
- * | P2 |
- * '------'
- */
-/* clang-format off */
-FIXTURE_VARIANT_ADD(hierarchy, deny_with_sibling_domain) {
- /* clang-format on */
- .domain_both = false,
- .domain_parent = true,
- .domain_child = true,
-};
-
-/*
- * Same domain (inherited)
- * .-------------.
- * | P1----. | P1 -> P2 : allow
- * | \ | P2 -> P1 : allow
- * | ' |
- * | P2 |
- * '-------------'
- */
-/* clang-format off */
-FIXTURE_VARIANT_ADD(hierarchy, allow_sibling_domain) {
- /* clang-format on */
- .domain_both = true,
- .domain_parent = false,
- .domain_child = false,
-};
-
-/*
- * Inherited + child domain
- * .-----------------.
- * | P1----. | P1 -> P2 : allow
- * | \ | P2 -> P1 : deny
- * | .-'----. |
- * | | P2 | |
- * | '------' |
- * '-----------------'
- */
-/* clang-format off */
-FIXTURE_VARIANT_ADD(hierarchy, allow_with_nested_domain) {
- /* clang-format on */
- .domain_both = true,
- .domain_parent = false,
- .domain_child = true,
-};
-
-/*
- * Inherited + parent domain
- * .-----------------.
- * |.------. | P1 -> P2 : deny
- * || P1 ----. | P2 -> P1 : allow
- * |'------' \ |
- * | ' |
- * | P2 |
- * '-----------------'
- */
-/* clang-format off */
-FIXTURE_VARIANT_ADD(hierarchy, deny_with_nested_and_parent_domain) {
- /* clang-format on */
- .domain_both = true,
- .domain_parent = true,
- .domain_child = false,
-};
-
-/*
- * Inherited + parent and child domain (siblings)
- * .-----------------.
- * | .------. | P1 -> P2 : deny
- * | | P1 . | P2 -> P1 : deny
- * | '------'\ |
- * | \ |
- * | .--'---. |
- * | | P2 | |
- * | '------' |
- * '-----------------'
- */
-/* clang-format off */
-FIXTURE_VARIANT_ADD(hierarchy, deny_with_forked_domain) {
- /* clang-format on */
- .domain_both = true,
- .domain_parent = true,
- .domain_child = true,
-};
-
-FIXTURE_SETUP(hierarchy)
+FIXTURE_SETUP(scoped_domains)
{
}
-FIXTURE_TEARDOWN(hierarchy)
+FIXTURE_TEARDOWN(scoped_domains)
{
}
/* Test PTRACE_TRACEME and PTRACE_ATTACH for parent and child. */
-TEST_F(hierarchy, trace)
+TEST_F(scoped_domains, trace)
{
pid_t child, parent;
int status, err_proc_read;
diff --git a/tools/testing/selftests/landlock/scoped_base_variants.h b/tools/testing/selftests/landlock/scoped_base_variants.h
index d3b1fa8a584e..7116728ebc68 100644
--- a/tools/testing/selftests/landlock/scoped_base_variants.h
+++ b/tools/testing/selftests/landlock/scoped_base_variants.h
@@ -1,8 +1,13 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
- * Landlock scoped_domains variants
+ * Landlock scoped_domains test variant definition.
*
- * See the hierarchy variants from ptrace_test.c
+ * This file defines a fixture variant "scoped_domains" that has all
+ * permutations of parent/child process being in separate or shared
+ * Landlock domain, or not being in a Landlock domain at all.
+ *
+ * Scoped access tests can include this file to avoid repeating these
+ * combinations.
*
* Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
* Copyright © 2019-2020 ANSSI
--
2.52.0
^ permalink raw reply related
* [RFC PATCH 5/5] landlock: Improve the comment for domain_is_scoped
From: Tingmao Wang @ 2025-12-28 1:27 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, linux-security-module,
Tahera Fahimi
In-Reply-To: <cover.1766885035.git.m@maowtm.org>
Currently it is not obvious what "scoped" mean, and the fact that the
function returns true when access should be denied is slightly surprising
and in need of documentation.
Cc: Tahera Fahimi <fahimitahera@gmail.com>
Signed-off-by: Tingmao Wang <m@maowtm.org>
---
Open to discussion on whether this actually explains it better.
security/landlock/task.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/security/landlock/task.c b/security/landlock/task.c
index bf4ed15a7f01..6dfcc1860d6e 100644
--- a/security/landlock/task.c
+++ b/security/landlock/task.c
@@ -166,15 +166,16 @@ static int hook_ptrace_traceme(struct task_struct *const parent)
}
/**
- * domain_is_scoped - Checks if the client domain is scoped in the same
- * domain as the server.
+ * domain_is_scoped - Check if an interaction from a client/sender to a
+ * server/receiver should be restricted based on scope controls.
*
* @client: IPC sender domain.
* @server: IPC receiver domain.
* @scope: The scope restriction criteria.
*
- * Returns: True if the @client domain is scoped to access the @server,
- * unless the @server is also scoped in the same domain as @client.
+ * Returns: True if the @server is in a different domain from @client, and
+ * the @client domain is scoped to access the @server (i.e. access
+ * should be denied).
*/
static bool domain_is_scoped(const struct landlock_ruleset *const client,
const struct landlock_ruleset *const server,
--
2.52.0
^ permalink raw reply related
* Re: [PATCH v2] ima: Fix stack-out-of-bounds in is_bprm_creds_for_exec()
From: Chris Arges @ 2025-12-28 3:16 UTC (permalink / raw)
To: Mimi Zohar
Cc: roberto.sassu, kernel-team, Dmitry Kasatkin, Eric Snowberg,
Paul Moore, James Morris, Serge E. Hallyn,
Mickaël Salaün, Kees Cook, linux-integrity,
linux-security-module, linux-kernel
In-Reply-To: <3aeed1ff9388f09555bf5c6ade03cbe9ce93ff14.camel@linux.ibm.com>
On 2025-12-23 16:58:26, Mimi Zohar wrote:
> Hi Chris,
>
> On Sun, 2025-12-21 at 12:01 -0600, Chris J Arges wrote:
> > KASAN reported a stack-out-of-bounds access in ima_appraise_measurement
> > from is_bprm_creds_for_exec:
> >
> > BUG: KASAN: stack-out-of-bounds in ima_appraise_measurement+0x12dc/0x16a0
> > Read of size 1 at addr ffffc9000160f940 by task sudo/550
> > The buggy address belongs to stack of task sudo/550
> > and is located at offset 24 in frame:
> > ima_appraise_measurement+0x0/0x16a0
> > This frame has 2 objects:
> > [48, 56) 'file'
> > [80, 148) 'hash'
> >
> > This is caused by using container_of on the *file pointer. This offset
> > calculation is what triggers the stack-out-of-bounds error.
> >
> > In order to fix this, pass in a bprm_is_check boolean which can be set
> > depending on how process_measurement is called. If the caller has a
> > linux_binprm pointer and the function is BPRM_CHECK we can determine
> > is_check and set it then. Otherwise set it to false.
> >
> > Fixes: 95b3cdafd7cb7 ("ima: instantiate the bprm_creds_for_exec() hook")
> >
> > Signed-off-by: Chris J Arges <carges@cloudflare.com>
>
> Thank you! I'd appreciate your limiting the line lengths to 80 chars (e.g.
> scripts/checkpatch.pl --max-line-length=80).
>
> --
> thanks,
>
> Mimi
Sure thing, I'll make that adjustment and send v3.
--chris
^ permalink raw reply
* [PATCH v3] ima: Fix stack-out-of-bounds in is_bprm_creds_for_exec()
From: Chris J Arges @ 2025-12-28 3:18 UTC (permalink / raw)
To: zohar, roberto.sassu
Cc: kernel-team, Chris J Arges, Dmitry Kasatkin, Eric Snowberg,
Paul Moore, James Morris, Serge E. Hallyn,
Mickaël Salaün, Kees Cook, linux-integrity,
linux-security-module, linux-kernel
In-Reply-To: <3aeed1ff9388f09555bf5c6ade03cbe9ce93ff14.camel@linux.ibm.com>
KASAN reported a stack-out-of-bounds access in ima_appraise_measurement
from is_bprm_creds_for_exec:
BUG: KASAN: stack-out-of-bounds in ima_appraise_measurement+0x12dc/0x16a0
Read of size 1 at addr ffffc9000160f940 by task sudo/550
The buggy address belongs to stack of task sudo/550
and is located at offset 24 in frame:
ima_appraise_measurement+0x0/0x16a0
This frame has 2 objects:
[48, 56) 'file'
[80, 148) 'hash'
This is caused by using container_of on the *file pointer. This offset
calculation is what triggers the stack-out-of-bounds error.
In order to fix this, pass in a bprm_is_check boolean which can be set
depending on how process_measurement is called. If the caller has a
linux_binprm pointer and the function is BPRM_CHECK we can determine
is_check and set it then. Otherwise set it to false.
Fixes: 95b3cdafd7cb7 ("ima: instantiate the bprm_creds_for_exec() hook")
Signed-off-by: Chris J Arges <carges@cloudflare.com>
---
security/integrity/ima/ima.h | 6 ++++--
security/integrity/ima/ima_appraise.c | 16 +++-------------
security/integrity/ima/ima_main.c | 22 +++++++++++++---------
3 files changed, 20 insertions(+), 24 deletions(-)
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index e3d71d8d56e3..89ebe98ffc5e 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -441,7 +441,8 @@ int ima_check_blacklist(struct ima_iint_cache *iint,
int ima_appraise_measurement(enum ima_hooks func, struct ima_iint_cache *iint,
struct file *file, const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
- int xattr_len, const struct modsig *modsig);
+ int xattr_len, const struct modsig *modsig,
+ bool bprm_is_check);
int ima_must_appraise(struct mnt_idmap *idmap, struct inode *inode,
int mask, enum ima_hooks func);
void ima_update_xattr(struct ima_iint_cache *iint, struct file *file);
@@ -466,7 +467,8 @@ static inline int ima_appraise_measurement(enum ima_hooks func,
const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
int xattr_len,
- const struct modsig *modsig)
+ const struct modsig *modsig,
+ bool bprm_is_check)
{
return INTEGRITY_UNKNOWN;
}
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 5149ff4fd50d..16c20c578ea8 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -470,17 +470,6 @@ int ima_check_blacklist(struct ima_iint_cache *iint,
return rc;
}
-static bool is_bprm_creds_for_exec(enum ima_hooks func, struct file *file)
-{
- struct linux_binprm *bprm;
-
- if (func == BPRM_CHECK) {
- bprm = container_of(&file, struct linux_binprm, file);
- return bprm->is_check;
- }
- return false;
-}
-
/*
* ima_appraise_measurement - appraise file measurement
*
@@ -492,7 +481,8 @@ static bool is_bprm_creds_for_exec(enum ima_hooks func, struct file *file)
int ima_appraise_measurement(enum ima_hooks func, struct ima_iint_cache *iint,
struct file *file, const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
- int xattr_len, const struct modsig *modsig)
+ int xattr_len, const struct modsig *modsig,
+ bool bprm_is_check)
{
static const char op[] = "appraise_data";
int audit_msgno = AUDIT_INTEGRITY_DATA;
@@ -514,7 +504,7 @@ int ima_appraise_measurement(enum ima_hooks func, struct ima_iint_cache *iint,
* of the script interpreter(userspace). Differentiate kernel and
* userspace enforced integrity audit messages.
*/
- if (is_bprm_creds_for_exec(func, file))
+ if (bprm_is_check)
audit_msgno = AUDIT_INTEGRITY_USERSPACE;
/* If reading the xattr failed and there's no modsig, error out. */
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 5770cf691912..1d6229b156fb 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -236,7 +236,8 @@ static void ima_file_free(struct file *file)
static int process_measurement(struct file *file, const struct cred *cred,
struct lsm_prop *prop, char *buf, loff_t size,
int mask, enum ima_hooks func,
- enum kernel_read_file_id read_id)
+ enum kernel_read_file_id read_id,
+ bool bprm_is_check)
{
struct inode *real_inode, *inode = file_inode(file);
struct ima_iint_cache *iint = NULL;
@@ -426,7 +427,8 @@ static int process_measurement(struct file *file, const struct cred *cred,
inode_lock(inode);
rc = ima_appraise_measurement(func, iint, file,
pathname, xattr_value,
- xattr_len, modsig);
+ xattr_len, modsig,
+ bprm_is_check);
inode_unlock(inode);
}
if (!rc)
@@ -493,14 +495,15 @@ static int ima_file_mmap(struct file *file, unsigned long reqprot,
if (reqprot & PROT_EXEC) {
ret = process_measurement(file, current_cred(), &prop, NULL,
- 0, MAY_EXEC, MMAP_CHECK_REQPROT, 0);
+ 0, MAY_EXEC, MMAP_CHECK_REQPROT, 0,
+ false);
if (ret)
return ret;
}
if (prot & PROT_EXEC)
return process_measurement(file, current_cred(), &prop, NULL,
- 0, MAY_EXEC, MMAP_CHECK, 0);
+ 0, MAY_EXEC, MMAP_CHECK, 0, false);
return 0;
}
@@ -584,7 +587,8 @@ static int ima_bprm_check(struct linux_binprm *bprm)
security_current_getlsmprop_subj(&prop);
return process_measurement(bprm->file, current_cred(),
- &prop, NULL, 0, MAY_EXEC, BPRM_CHECK, 0);
+ &prop, NULL, 0, MAY_EXEC, BPRM_CHECK, 0,
+ bprm->is_check);
}
/**
@@ -614,7 +618,7 @@ static int ima_creds_check(struct linux_binprm *bprm, const struct file *file)
security_current_getlsmprop_subj(&prop);
return process_measurement((struct file *)file, bprm->cred, &prop, NULL,
- 0, MAY_EXEC, CREDS_CHECK, 0);
+ 0, MAY_EXEC, CREDS_CHECK, 0, false);
}
/**
@@ -662,7 +666,7 @@ static int ima_file_check(struct file *file, int mask)
security_current_getlsmprop_subj(&prop);
return process_measurement(file, current_cred(), &prop, NULL, 0,
mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
- MAY_APPEND), FILE_CHECK, 0);
+ MAY_APPEND), FILE_CHECK, 0, false);
}
static int __ima_inode_hash(struct inode *inode, struct file *file, char *buf,
@@ -881,7 +885,7 @@ static int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
func = read_idmap[read_id] ?: FILE_CHECK;
security_current_getlsmprop_subj(&prop);
return process_measurement(file, current_cred(), &prop, NULL, 0,
- MAY_READ, func, 0);
+ MAY_READ, func, 0, false);
}
const int read_idmap[READING_MAX_ID] = {
@@ -925,7 +929,7 @@ static int ima_post_read_file(struct file *file, char *buf, loff_t size,
func = read_idmap[read_id] ?: FILE_CHECK;
security_current_getlsmprop_subj(&prop);
return process_measurement(file, current_cred(), &prop, buf, size,
- MAY_READ, func, read_id);
+ MAY_READ, func, read_id, false);
}
/**
--
2.43.0
^ permalink raw reply related
* Re: [syzbot] [lsm?] [integrity?] INFO: task hung in process_measurement (3)
From: syzbot @ 2025-12-28 6:29 UTC (permalink / raw)
To: bfoster, dmitry.kasatkin, eric.snowberg, jmorris, kent.overstreet,
linux-bcachefs, linux-integrity, linux-kernel,
linux-security-module, paul, roberto.sassu, serge, syzkaller-bugs,
torvalds, zohar
In-Reply-To: <682e11b1.050a0220.ade60.09e5.GAE@google.com>
syzbot suspects this issue was fixed by commit:
commit f2c61db29f277b9c80de92102fc532cc247495cd
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Mon Sep 29 20:43:52 2025 +0000
Remove bcachefs core code
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10499e2a580000
start commit: 172a9d94339c Merge tag '6.15-rc6-smb3-client-fixes' of git..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=ea35e429f965296e
dashboard link: https://syzkaller.appspot.com/bug?extid=cb9e66807bcb882cd0c5
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16836e70580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1617a2d4580000
If the result looks correct, please mark the issue as fixed by replying with:
#syz fix: Remove bcachefs core code
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
^ permalink raw reply
* [PATCH 0/6] Landlock: Implement scope control for pathname Unix sockets
From: Tingmao Wang @ 2025-12-28 12:45 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, linux-security-module
This patch series extend the existing abstract Unix socket scoping to
pathname (i.e. normal file-based) sockets as well, by adding a new scope
bit LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET that works the same as
LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET, except that restricts pathname Unix
sockets. This means that a sandboxed process with this scope enabled will
not be able to connect to Unix sockets created outside the sandbox via the
filesystem.
There is a future plan [1] for allowing specific sockets based on FS
hierarchy, but this series is only determining access based on domain
parent-child relationship. There is currently no way to allow specific
(outside the Landlock domain) Unix sockets, and none of the existing
Landlock filesystem controls apply to socket connect().
With this series, we can now properly protect against things like the the
following (while only relying on Landlock):
(running under tmux)
root@6-19-0-rc1-dev-00023-g68f0b276cbeb ~# LL_FS_RO=/ LL_FS_RW= ./sandboxer bash
Executing the sandboxed command...
root@6-19-0-rc1-dev-00023-g68f0b276cbeb:/# cat /tmp/hi
cat: /tmp/hi: No such file or directory
root@6-19-0-rc1-dev-00023-g68f0b276cbeb:/# tmux new-window 'echo hi > /tmp/hi'
root@6-19-0-rc1-dev-00023-g68f0b276cbeb:/# cat /tmp/hi
hi
The above but with Unix socket scoping enabled (both pathname and abstract
sockets) - the sandboxed shell can now no longer talk to tmux due to the
socket being created from outside the Landlock sandbox:
(running under tmux)
root@6-19-0-rc1-dev-00023-g68f0b276cbeb ~# LL_FS_RO=/ LL_FS_RW= LL_SCOPED=u:a ./sandboxer bash
Executing the sandboxed command...
root@6-19-0-rc1-dev-00023-g68f0b276cbeb:/# cat /tmp/hi
cat: /tmp/hi: No such file or directory
root@6-19-0-rc1-dev-00023-g68f0b276cbeb:/# tmux new-window 'echo hi > /tmp/hi'
error connecting to /tmp/tmux-0/default (Operation not permitted)
root@6-19-0-rc1-dev-00023-g68f0b276cbeb:/# cat /tmp/hi
cat: /tmp/hi: No such file or directory
Tmux is just one example. In a standard systemd session, `systemd-run
--user` can also be used (--user will run the command in the user's
session, without requiring any root privileges), and likely a lot more if
running in a desktop environment with many popular applications. This
change therefore makes it possible to create sandboxes without relying on
additional mechanisms like seccomp to protect against such issues.
These kind of issues was originally discussed on here (I took the idea for
systemd-run from Demi):
https://spectrum-os.org/lists/archives/spectrum-devel/00256266-26db-40cf-8f5b-f7c7064084c2@gmail.com/
Demo with socat + sandboxer:
Outside:
socat unix-listen:/foo.sock,fork -
Sandbox with pathname socket scope bit:
root@6-19-0-rc1-dev-00023-g0994a10d6512 ~# LL_FS_RW=/ LL_FS_RO= LL_SCOPED=u /sandboxer socat -d2 unix:/foo.sock -
Executing the sandboxed command...
2025/12/27 20:28:54 socat[1227] E UNIX-CLIENT: /foo.sock: Operation not permitted
2025/12/27 20:28:54 socat[1227] N exit(1)
Sandbox without pathname socket scope bit:
root@6-19-0-rc1-dev-00023-g0994a10d6512 ~# LL_FS_RW=/ LL_FS_RO= LL_SCOPED= /sandboxer socat -d2 unix:/foo.sock -
Executing the sandboxed command...
2025/12/27 20:29:22 socat[1250] N successfully connected from local address AF=1 "(7\xAE\xAE\xAE\xAE\xAE\xAE\xAE\xAE\xAE\xAE\xAE\xAE\xB0\xAE\xAE\xAE\xAE\xAE\xAE\xAE\xAE\xAE\xAE\xC3\xAE\xAE\xAE\xAE"
...
Sandbox with only abstract socket scope bit:
root@6-19-0-rc1-dev-00023-g0994a10d6512 ~# LL_FS_RW=/ LL_FS_RO= LL_SCOPED=a /sandboxer socat -d2 unix:/foo.sock -
Executing the sandboxed command...
2025/12/27 20:29:26 socat[1259] N successfully connected from local address AF=1 "\0\0\0\0\0\0\0\0\0"
...
Sendmsg/recvmsg - outside:
socat unix-recvfrom:/datagram.sock -
Sandbox with pathname socket scope bit:
root@6-19-0-rc1-dev-00023-g0994a10d6512 ~# LL_FS_RW=/ LL_FS_RO= LL_SCOPED=u /sandboxer socat -d2 unix-sendto:/datagram.sock -
Executing the sandboxed command...
...
2025/12/27 20:33:04 socat[1446] N starting data transfer loop with FDs [5,5] and [0,1]
123
2025/12/27 20:33:05 socat[1446] E sendto(5, 0x55d260d8f000, 4, 0, AF=1 "/datagram.sock", 16): Operation not permitted
2025/12/27 20:33:05 socat[1446] N exit(1)
[1]: https://github.com/landlock-lsm/linux/issues/36
Closes: https://github.com/landlock-lsm/linux/issues/51
Tingmao Wang (6):
landlock: Add LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET scope bit to uAPI
landlock: Implement LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
samples/landlock: Support LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
selftests/landlock: Support pathname socket path in set_unix_address
selftests/landlock: Repurpose scoped_abstract_unix_test.c for pathname
sockets too.
selftests/landlock: Add pathname socket variants for more tests
Documentation/userspace-api/landlock.rst | 37 +-
include/uapi/linux/landlock.h | 8 +-
samples/landlock/sandboxer.c | 23 +-
security/landlock/audit.c | 4 +
security/landlock/audit.h | 1 +
security/landlock/limits.h | 2 +-
security/landlock/syscalls.c | 2 +-
security/landlock/task.c | 74 +-
tools/testing/selftests/landlock/base_test.c | 2 +-
tools/testing/selftests/landlock/common.h | 33 +-
tools/testing/selftests/landlock/net_test.c | 2 +-
.../selftests/landlock/scoped_signal_test.c | 2 +-
.../testing/selftests/landlock/scoped_test.c | 2 +-
...bstract_unix_test.c => scoped_unix_test.c} | 855 ++++++++++++------
14 files changed, 752 insertions(+), 295 deletions(-)
rename tools/testing/selftests/landlock/{scoped_abstract_unix_test.c => scoped_unix_test.c} (51%)
base-commit: 161db1810f3625e97ab414908dbcf4b2ab73c309
prerequisite-patch-id: 4eaf9fc84a1911a86c8a5db5a48e1e30dd13988f # https://lore.kernel.org/all/cover.1766885035.git.m@maowtm.org/
prerequisite-patch-id: b0750cf8e20fbd1b39b0836da7a980a9592a461b
prerequisite-patch-id: 4b6d65083f8b677c5dd249eb28625c152f5e91ab
prerequisite-patch-id: 2558c06992f9a689b11f05ae26acf26b7d56fa28
prerequisite-patch-id: 87beca2ee8cb7fc774ebff8449817e98fb849efa
--
2.52.0
^ permalink raw reply
* [PATCH 1/6] landlock: Add LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET scope bit to uAPI
From: Tingmao Wang @ 2025-12-28 12:45 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, linux-security-module
In-Reply-To: <cover.1766925301.git.m@maowtm.org>
Add the new scope bit to the uAPI header, add documentation, and bump ABI
version to 8.
This documentation edit specifically calls out the security implications of
not restricting sockets.
Fix some minor cosmetic issue in landlock.h around the changed lines as
well.
Signed-off-by: Tingmao Wang <m@maowtm.org>
---
Documentation/userspace-api/landlock.rst | 37 ++++++++++++++++---
include/uapi/linux/landlock.h | 8 +++-
security/landlock/limits.h | 2 +-
security/landlock/syscalls.c | 2 +-
tools/testing/selftests/landlock/base_test.c | 2 +-
.../testing/selftests/landlock/scoped_test.c | 2 +-
6 files changed, 42 insertions(+), 11 deletions(-)
diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst
index 903d2ad11852..8f4cad332b63 100644
--- a/Documentation/userspace-api/landlock.rst
+++ b/Documentation/userspace-api/landlock.rst
@@ -83,7 +83,8 @@ to be explicit about the denied-by-default access rights.
LANDLOCK_ACCESS_NET_CONNECT_TCP,
.scoped =
LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
- LANDLOCK_SCOPE_SIGNAL,
+ LANDLOCK_SCOPE_SIGNAL |
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET,
};
Because we may not know which kernel version an application will be executed
@@ -133,6 +134,10 @@ version, and only use the available subset of access rights:
supported_restrict_flags &= ~(LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON |
LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF |
LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF);
+ __attribute__((fallthrough));
+ case 7:
+ /* Removes LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET for ABI < 8 */
+ ruleset_attr.scoped &= ~LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
}
This enables the creation of an inclusive ruleset that will contain our rules.
@@ -334,10 +339,15 @@ The operations which can be scoped are:
This limits the sending of signals to target processes which run within the
same or a nested Landlock domain.
-``LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET``
- This limits the set of abstract :manpage:`unix(7)` sockets to which we can
- :manpage:`connect(2)` to socket addresses which were created by a process in
- the same or a nested Landlock domain.
+``LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET`` and ``LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET``
+ This limits the set of :manpage:`unix(7)` sockets to which we can
+ :manpage:`connect(2)` to socket addresses which were created by a
+ process in the same or a nested Landlock domain.
+ ``LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET`` applies to abstract sockets,
+ and ``LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET`` applies to pathname
+ sockets. Even though pathname sockets are represented in the
+ filesystem, Landlock filesystem rules do not currently control access
+ to them.
A :manpage:`sendto(2)` on a non-connected datagram socket is treated as if
it were doing an implicit :manpage:`connect(2)` and will be blocked if the
@@ -610,6 +620,23 @@ Landlock audit events with the ``LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF``,
sys_landlock_restrict_self(). See Documentation/admin-guide/LSM/landlock.rst
for more details on audit.
+Pathname UNIX socket (ABI < 8)
+------------------------------
+
+Starting with the Landlock ABI version 8, it is possible to restrict
+connections to a pathname (non-abstract) :manpage:`unix(7)` socket by
+setting ``LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET`` to the ``scoped`` ruleset
+attribute. This works the same way as the abstract socket scoping.
+
+This allows sandboxing applications using only Landlock to protect against
+bypasses relying on connecting to Unix sockets of other services running
+under the same user. These services typically assumes that any process
+capable of connecting to a local Unix socket, or connecting with the
+expected user credentials, is trusted. Without this protection, sandbox
+escapes may be possible, especially when running in a standard desktop
+environment, such as by using systemd-run, or sockets exposed by other
+common applications.
+
.. _kernel_support:
Kernel support
diff --git a/include/uapi/linux/landlock.h b/include/uapi/linux/landlock.h
index f030adc462ee..590c6d4171a0 100644
--- a/include/uapi/linux/landlock.h
+++ b/include/uapi/linux/landlock.h
@@ -364,10 +364,14 @@ struct landlock_net_port_attr {
* related Landlock domain (e.g., a parent domain or a non-sandboxed process).
* - %LANDLOCK_SCOPE_SIGNAL: Restrict a sandboxed process from sending a signal
* to another process outside the domain.
+ * - %LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET: Restrict a sandboxed process from
+ * connecting to a pathname UNIX socket created by a process outside the
+ * related Landlock domain.
*/
/* clang-format off */
#define LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET (1ULL << 0)
-#define LANDLOCK_SCOPE_SIGNAL (1ULL << 1)
-/* clang-format on*/
+#define LANDLOCK_SCOPE_SIGNAL (1ULL << 1)
+#define LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET (1ULL << 2)
+/* clang-format on */
#endif /* _UAPI_LINUX_LANDLOCK_H */
diff --git a/security/landlock/limits.h b/security/landlock/limits.h
index 65b5ff051674..d653e14dba10 100644
--- a/security/landlock/limits.h
+++ b/security/landlock/limits.h
@@ -27,7 +27,7 @@
#define LANDLOCK_MASK_ACCESS_NET ((LANDLOCK_LAST_ACCESS_NET << 1) - 1)
#define LANDLOCK_NUM_ACCESS_NET __const_hweight64(LANDLOCK_MASK_ACCESS_NET)
-#define LANDLOCK_LAST_SCOPE LANDLOCK_SCOPE_SIGNAL
+#define LANDLOCK_LAST_SCOPE LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
#define LANDLOCK_MASK_SCOPE ((LANDLOCK_LAST_SCOPE << 1) - 1)
#define LANDLOCK_NUM_SCOPE __const_hweight64(LANDLOCK_MASK_SCOPE)
diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c
index 0116e9f93ffe..66fd196be85a 100644
--- a/security/landlock/syscalls.c
+++ b/security/landlock/syscalls.c
@@ -161,7 +161,7 @@ static const struct file_operations ruleset_fops = {
* Documentation/userspace-api/landlock.rst should be updated to reflect the
* UAPI change.
*/
-const int landlock_abi_version = 7;
+const int landlock_abi_version = 8;
/**
* sys_landlock_create_ruleset - Create a new ruleset
diff --git a/tools/testing/selftests/landlock/base_test.c b/tools/testing/selftests/landlock/base_test.c
index 7b69002239d7..f4b1a275d8d9 100644
--- a/tools/testing/selftests/landlock/base_test.c
+++ b/tools/testing/selftests/landlock/base_test.c
@@ -76,7 +76,7 @@ TEST(abi_version)
const struct landlock_ruleset_attr ruleset_attr = {
.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
};
- ASSERT_EQ(7, landlock_create_ruleset(NULL, 0,
+ ASSERT_EQ(8, landlock_create_ruleset(NULL, 0,
LANDLOCK_CREATE_RULESET_VERSION));
ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, 0,
diff --git a/tools/testing/selftests/landlock/scoped_test.c b/tools/testing/selftests/landlock/scoped_test.c
index b90f76ed0d9c..7f83512a328d 100644
--- a/tools/testing/selftests/landlock/scoped_test.c
+++ b/tools/testing/selftests/landlock/scoped_test.c
@@ -12,7 +12,7 @@
#include "common.h"
-#define ACCESS_LAST LANDLOCK_SCOPE_SIGNAL
+#define ACCESS_LAST LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
TEST(ruleset_with_unknown_scope)
{
--
2.52.0
^ permalink raw reply related
* [PATCH 2/6] landlock: Implement LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
From: Tingmao Wang @ 2025-12-28 12:45 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, linux-security-module
In-Reply-To: <cover.1766925301.git.m@maowtm.org>
Extend the existing abstract UNIX socket scoping to pathname sockets as
well. Basically all of the logic is reused between the two types, just
that pathname sockets scoping are controlled by another bit, and has its
own audit request type (since the current one is named
"abstract_unix_socket").
Closes: https://github.com/landlock-lsm/linux/issues/51
Signed-off-by: Tingmao Wang <m@maowtm.org>
---
There is an argument that there should only really be one audit request
type for both sockets, since the only difference is whether path= is
followed by a normal path, or by a hex string starting with 00. But I'm
not sure if we can change this at this point, so I have created a new
request type.
security/landlock/audit.c | 4 +++
security/landlock/audit.h | 1 +
security/landlock/task.c | 74 ++++++++++++++++++++++++++++++---------
3 files changed, 62 insertions(+), 17 deletions(-)
diff --git a/security/landlock/audit.c b/security/landlock/audit.c
index e899995f1fd5..0626cc553ab0 100644
--- a/security/landlock/audit.c
+++ b/security/landlock/audit.c
@@ -75,6 +75,10 @@ get_blocker(const enum landlock_request_type type,
WARN_ON_ONCE(access_bit != -1);
return "scope.abstract_unix_socket";
+ case LANDLOCK_REQUEST_SCOPE_PATHNAME_UNIX_SOCKET:
+ WARN_ON_ONCE(access_bit != -1);
+ return "scope.pathname_unix_socket";
+
case LANDLOCK_REQUEST_SCOPE_SIGNAL:
WARN_ON_ONCE(access_bit != -1);
return "scope.signal";
diff --git a/security/landlock/audit.h b/security/landlock/audit.h
index 92428b7fc4d8..1c9ce8588102 100644
--- a/security/landlock/audit.h
+++ b/security/landlock/audit.h
@@ -21,6 +21,7 @@ enum landlock_request_type {
LANDLOCK_REQUEST_NET_ACCESS,
LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET,
LANDLOCK_REQUEST_SCOPE_SIGNAL,
+ LANDLOCK_REQUEST_SCOPE_PATHNAME_UNIX_SOCKET,
};
/*
diff --git a/security/landlock/task.c b/security/landlock/task.c
index 6dfcc1860d6e..9fbb0ada440b 100644
--- a/security/landlock/task.c
+++ b/security/landlock/task.c
@@ -233,57 +233,84 @@ static bool domain_is_scoped(const struct landlock_ruleset *const client,
return false;
}
+/**
+ * sock_is_scoped - Check if socket connect or send should be restricted
+ * based on scope controls.
+ *
+ * @other: The server socket.
+ * @domain: The client domain.
+ * @scope: The relevant scope bit to check (i.e. pathname or abstract).
+ *
+ * Returns: True if connect should be restricted, false otherwise.
+ */
static bool sock_is_scoped(struct sock *const other,
- const struct landlock_ruleset *const domain)
+ const struct landlock_ruleset *const domain,
+ access_mask_t scope)
{
const struct landlock_ruleset *dom_other;
/* The credentials will not change. */
lockdep_assert_held(&unix_sk(other)->lock);
dom_other = landlock_cred(other->sk_socket->file->f_cred)->domain;
- return domain_is_scoped(domain, dom_other,
- LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ return domain_is_scoped(domain, dom_other, scope);
}
-static bool is_abstract_socket(struct sock *const sock)
+static bool sock_addr_is_abstract(const struct unix_address *const addr)
{
- struct unix_address *addr = unix_sk(sock)->addr;
-
- if (!addr)
- return false;
-
- if (addr->len >= offsetof(struct sockaddr_un, sun_path) + 1 &&
+ if (addr && addr->len >= offsetof(struct sockaddr_un, sun_path) + 1 &&
addr->name->sun_path[0] == '\0')
return true;
return false;
}
+/* Allow us to quickly test if the current domain scopes any form of socket */
static const struct access_masks unix_scope = {
- .scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET,
+ .scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET,
};
+/*
+ * UNIX sockets can have three types of addresses: pathname (a filesystem path),
+ * unnamed (not bound to an address), and abstract (sun_path[0] is '\0').
+ * Unnamed sockets include those created with socketpair() and unbound sockets.
+ * We do not restrict unnamed sockets since they have no address to identify.
+ */
static int hook_unix_stream_connect(struct sock *const sock,
struct sock *const other,
struct sock *const newsk)
{
size_t handle_layer;
+ access_mask_t scope;
+ enum landlock_request_type request_type;
const struct landlock_cred_security *const subject =
landlock_get_applicable_subject(current_cred(), unix_scope,
&handle_layer);
+ const struct unix_address *addr;
/* Quick return for non-landlocked tasks. */
if (!subject)
return 0;
- if (!is_abstract_socket(other))
+ addr = unix_sk(other)->addr;
+ /* Unnamed sockets are not restricted. */
+ if (!addr)
return 0;
- if (!sock_is_scoped(other, subject->domain))
+ if (sock_addr_is_abstract(addr)) {
+ scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET;
+ request_type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET;
+ } else {
+ /* Pathname socket. */
+ scope = LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
+ request_type = LANDLOCK_REQUEST_SCOPE_PATHNAME_UNIX_SOCKET;
+ }
+
+ if (!sock_is_scoped(other, subject->domain, scope))
return 0;
landlock_log_denial(subject, &(struct landlock_request) {
- .type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET,
+ .type = request_type,
.audit = {
.type = LSM_AUDIT_DATA_NET,
.u.net = &(struct lsm_network_audit) {
@@ -299,9 +326,12 @@ static int hook_unix_may_send(struct socket *const sock,
struct socket *const other)
{
size_t handle_layer;
+ access_mask_t scope;
+ enum landlock_request_type request_type;
const struct landlock_cred_security *const subject =
landlock_get_applicable_subject(current_cred(), unix_scope,
&handle_layer);
+ const struct unix_address *addr;
if (!subject)
return 0;
@@ -313,14 +343,24 @@ static int hook_unix_may_send(struct socket *const sock,
if (unix_peer(sock->sk) == other->sk)
return 0;
- if (!is_abstract_socket(other->sk))
+ addr = unix_sk(other->sk)->addr;
+ /* Unnamed sockets are not restricted. */
+ if (!addr)
return 0;
- if (!sock_is_scoped(other->sk, subject->domain))
+ if (sock_addr_is_abstract(addr)) {
+ scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET;
+ request_type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET;
+ } else {
+ scope = LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
+ request_type = LANDLOCK_REQUEST_SCOPE_PATHNAME_UNIX_SOCKET;
+ }
+
+ if (!sock_is_scoped(other->sk, subject->domain, scope))
return 0;
landlock_log_denial(subject, &(struct landlock_request) {
- .type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET,
+ .type = request_type,
.audit = {
.type = LSM_AUDIT_DATA_NET,
.u.net = &(struct lsm_network_audit) {
--
2.52.0
^ permalink raw reply related
* [PATCH 3/6] samples/landlock: Support LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
From: Tingmao Wang @ 2025-12-28 12:45 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, linux-security-module
In-Reply-To: <cover.1766925301.git.m@maowtm.org>
Signed-off-by: Tingmao Wang <m@maowtm.org>
---
I've decided to use "u" as the character to control this scope bit since
it stands for (normal) Unix sockets. Imo using "p" or "n" would make it less
clear / memorable. Open to suggestions.
Also, open to suggestion whether socket scoping (pathname and abstract)
should be enabled by default, if LL_SCOPED is not set. This would break
backward compatibility, but maybe we shouldn't guarentee backward
compatibility of this sandboxer in the first place, and almost all cases
of Landlock usage would want socket scoping.
samples/landlock/sandboxer.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c
index e7af02f98208..2de14e1c787d 100644
--- a/samples/landlock/sandboxer.c
+++ b/samples/landlock/sandboxer.c
@@ -234,14 +234,16 @@ static bool check_ruleset_scope(const char *const env_var,
bool error = false;
bool abstract_scoping = false;
bool signal_scoping = false;
+ bool named_scoping = false;
/* Scoping is not supported by Landlock ABI */
if (!(ruleset_attr->scoped &
- (LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET | LANDLOCK_SCOPE_SIGNAL)))
+ (LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET | LANDLOCK_SCOPE_SIGNAL |
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET)))
goto out_unset;
env_type_scope = getenv(env_var);
- /* Scoping is not supported by the user */
+ /* Scoping is not requested by the user */
if (!env_type_scope || strcmp("", env_type_scope) == 0)
goto out_unset;
@@ -254,6 +256,9 @@ static bool check_ruleset_scope(const char *const env_var,
} else if (strcmp("s", ipc_scoping_name) == 0 &&
!signal_scoping) {
signal_scoping = true;
+ } else if (strcmp("u", ipc_scoping_name) == 0 &&
+ !named_scoping) {
+ named_scoping = true;
} else {
fprintf(stderr, "Unknown or duplicate scope \"%s\"\n",
ipc_scoping_name);
@@ -270,6 +275,8 @@ static bool check_ruleset_scope(const char *const env_var,
ruleset_attr->scoped &= ~LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET;
if (!signal_scoping)
ruleset_attr->scoped &= ~LANDLOCK_SCOPE_SIGNAL;
+ if (!named_scoping)
+ ruleset_attr->scoped &= ~LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
unsetenv(env_var);
return error;
@@ -299,7 +306,7 @@ static bool check_ruleset_scope(const char *const env_var,
/* clang-format on */
-#define LANDLOCK_ABI_LAST 7
+#define LANDLOCK_ABI_LAST 8
#define XSTR(s) #s
#define STR(s) XSTR(s)
@@ -325,6 +332,7 @@ static const char help[] =
"* " ENV_SCOPED_NAME ": actions denied on the outside of the landlock domain\n"
" - \"a\" to restrict opening abstract unix sockets\n"
" - \"s\" to restrict sending signals\n"
+ " - \"u\" to restrict opening pathname (non-abstract) unix sockets\n"
"\n"
"A sandboxer should not log denied access requests to avoid spamming logs, "
"but to test audit we can set " ENV_FORCE_LOG_NAME "=1\n"
@@ -334,7 +342,7 @@ static const char help[] =
ENV_FS_RW_NAME "=\"/dev/null:/dev/full:/dev/zero:/dev/pts:/tmp\" "
ENV_TCP_BIND_NAME "=\"9418\" "
ENV_TCP_CONNECT_NAME "=\"80:443\" "
- ENV_SCOPED_NAME "=\"a:s\" "
+ ENV_SCOPED_NAME "=\"a:s:u\" "
"%1$s bash -i\n"
"\n"
"This sandboxer can use Landlock features up to ABI version "
@@ -356,7 +364,8 @@ int main(const int argc, char *const argv[], char *const *const envp)
.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
LANDLOCK_ACCESS_NET_CONNECT_TCP,
.scoped = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
- LANDLOCK_SCOPE_SIGNAL,
+ LANDLOCK_SCOPE_SIGNAL |
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET,
};
int supported_restrict_flags = LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON;
int set_restrict_flags = 0;
@@ -436,6 +445,10 @@ int main(const int argc, char *const argv[], char *const *const envp)
/* Removes LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON for ABI < 7 */
supported_restrict_flags &=
~LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON;
+ __attribute__((fallthrough));
+ case 7:
+ /* Removes LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET for ABI < 8 */
+ ruleset_attr.scoped &= ~LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
/* Must be printed for any ABI < LANDLOCK_ABI_LAST. */
fprintf(stderr,
--
2.52.0
^ permalink raw reply related
* [PATCH 4/6] selftests/landlock: Support pathname socket path in set_unix_address
From: Tingmao Wang @ 2025-12-28 12:45 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, linux-security-module
In-Reply-To: <cover.1766925301.git.m@maowtm.org>
To prepare for extending the socket tests to do non-abstract sockets too,
extend set_unix_address() to also be able to populate a non-abstract
socket path under TMP_DIR. Also use snprintf for good measure.
This also changes existing callers to pass true for the abstract argument.
Signed-off-by: Tingmao Wang <m@maowtm.org>
---
tools/testing/selftests/landlock/common.h | 33 +++++++++++++++----
tools/testing/selftests/landlock/net_test.c | 2 +-
.../landlock/scoped_abstract_unix_test.c | 30 ++++++++---------
.../selftests/landlock/scoped_signal_test.c | 2 +-
4 files changed, 44 insertions(+), 23 deletions(-)
diff --git a/tools/testing/selftests/landlock/common.h b/tools/testing/selftests/landlock/common.h
index 90551650299c..c55c11434e27 100644
--- a/tools/testing/selftests/landlock/common.h
+++ b/tools/testing/selftests/landlock/common.h
@@ -241,13 +241,34 @@ struct service_fixture {
};
};
+#define PATHNAME_UNIX_SOCK_DIR TMP_DIR
+
+/**
+ * set_unix_address - Set up srv->unix_addr and srv->unix_addr_len.
+ * @srv: Service fixture containing the socket address to initialize
+ * @index: Index to include in socket names
+ * @abstract: If true, creates an abstract socket address (sun_path[0] ==
+ * '\0') with the given name. If false, creates a pathname socket
+ * address with the given path.
+ */
static void __maybe_unused set_unix_address(struct service_fixture *const srv,
- const unsigned short index)
+ const unsigned short index,
+ const bool abstract)
{
srv->unix_addr.sun_family = AF_UNIX;
- sprintf(srv->unix_addr.sun_path,
- "_selftests-landlock-abstract-unix-tid%d-index%d", sys_gettid(),
- index);
- srv->unix_addr_len = SUN_LEN(&srv->unix_addr);
- srv->unix_addr.sun_path[0] = '\0';
+ if (abstract) {
+ snprintf(srv->unix_addr.sun_path,
+ sizeof(srv->unix_addr.sun_path),
+ "_selftests-landlock-abstract-unix-tid%d-index%d",
+ sys_gettid(), index);
+ srv->unix_addr_len = SUN_LEN(&srv->unix_addr);
+ srv->unix_addr.sun_path[0] = '\0';
+ } else {
+ snprintf(srv->unix_addr.sun_path,
+ sizeof(srv->unix_addr.sun_path),
+ PATHNAME_UNIX_SOCK_DIR
+ "/pathname-unix-tid%d-index%d.sock",
+ sys_gettid(), index);
+ srv->unix_addr_len = sizeof(srv->unix_addr);
+ }
}
diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
index b34b139b3f89..fd3fe51ce92f 100644
--- a/tools/testing/selftests/landlock/net_test.c
+++ b/tools/testing/selftests/landlock/net_test.c
@@ -69,7 +69,7 @@ static int set_service(struct service_fixture *const srv,
return 0;
case AF_UNIX:
- set_unix_address(srv, index);
+ set_unix_address(srv, index, true);
return 0;
}
return 1;
diff --git a/tools/testing/selftests/landlock/scoped_abstract_unix_test.c b/tools/testing/selftests/landlock/scoped_abstract_unix_test.c
index 72f97648d4a7..4a790e2d387d 100644
--- a/tools/testing/selftests/landlock/scoped_abstract_unix_test.c
+++ b/tools/testing/selftests/landlock/scoped_abstract_unix_test.c
@@ -58,8 +58,8 @@ FIXTURE_SETUP(scoped_domains)
memset(&self->stream_address, 0, sizeof(self->stream_address));
memset(&self->dgram_address, 0, sizeof(self->dgram_address));
- set_unix_address(&self->stream_address, 0);
- set_unix_address(&self->dgram_address, 1);
+ set_unix_address(&self->stream_address, 0, true);
+ set_unix_address(&self->dgram_address, 1, true);
}
FIXTURE_TEARDOWN(scoped_domains)
@@ -280,7 +280,7 @@ FIXTURE_SETUP(scoped_audit)
disable_caps(_metadata);
memset(&self->dgram_address, 0, sizeof(self->dgram_address));
- set_unix_address(&self->dgram_address, 1);
+ set_unix_address(&self->dgram_address, 1, true);
set_cap(_metadata, CAP_AUDIT_CONTROL);
self->audit_fd = audit_init_with_exe_filter(&self->audit_filter);
@@ -392,16 +392,16 @@ FIXTURE_SETUP(scoped_vs_unscoped)
memset(&self->parent_stream_address, 0,
sizeof(self->parent_stream_address));
- set_unix_address(&self->parent_stream_address, 0);
+ set_unix_address(&self->parent_stream_address, 0, true);
memset(&self->parent_dgram_address, 0,
sizeof(self->parent_dgram_address));
- set_unix_address(&self->parent_dgram_address, 1);
+ set_unix_address(&self->parent_dgram_address, 1, true);
memset(&self->child_stream_address, 0,
sizeof(self->child_stream_address));
- set_unix_address(&self->child_stream_address, 2);
+ set_unix_address(&self->child_stream_address, 2, true);
memset(&self->child_dgram_address, 0,
sizeof(self->child_dgram_address));
- set_unix_address(&self->child_dgram_address, 3);
+ set_unix_address(&self->child_dgram_address, 3, true);
}
FIXTURE_TEARDOWN(scoped_vs_unscoped)
@@ -622,9 +622,9 @@ FIXTURE_SETUP(outside_socket)
drop_caps(_metadata);
memset(&self->transit_address, 0, sizeof(self->transit_address));
- set_unix_address(&self->transit_address, 0);
+ set_unix_address(&self->transit_address, 0, true);
memset(&self->address, 0, sizeof(self->address));
- set_unix_address(&self->address, 1);
+ set_unix_address(&self->address, 1, true);
}
FIXTURE_TEARDOWN(outside_socket)
@@ -802,9 +802,9 @@ TEST_F(various_address_sockets, scoped_pathname_sockets)
/* Abstract address. */
memset(&stream_abstract_addr, 0, sizeof(stream_abstract_addr));
- set_unix_address(&stream_abstract_addr, 0);
+ set_unix_address(&stream_abstract_addr, 0, true);
memset(&dgram_abstract_addr, 0, sizeof(dgram_abstract_addr));
- set_unix_address(&dgram_abstract_addr, 1);
+ set_unix_address(&dgram_abstract_addr, 1, true);
/* Unnamed address for datagram socket. */
ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_DGRAM, 0, unnamed_sockets));
@@ -990,9 +990,9 @@ TEST(datagram_sockets)
drop_caps(_metadata);
memset(&connected_addr, 0, sizeof(connected_addr));
- set_unix_address(&connected_addr, 0);
+ set_unix_address(&connected_addr, 0, true);
memset(&non_connected_addr, 0, sizeof(non_connected_addr));
- set_unix_address(&non_connected_addr, 1);
+ set_unix_address(&non_connected_addr, 1, true);
ASSERT_EQ(0, pipe2(pipe_parent, O_CLOEXEC));
ASSERT_EQ(0, pipe2(pipe_child, O_CLOEXEC));
@@ -1090,9 +1090,9 @@ TEST(self_connect)
drop_caps(_metadata);
memset(&connected_addr, 0, sizeof(connected_addr));
- set_unix_address(&connected_addr, 0);
+ set_unix_address(&connected_addr, 0, true);
memset(&non_connected_addr, 0, sizeof(non_connected_addr));
- set_unix_address(&non_connected_addr, 1);
+ set_unix_address(&non_connected_addr, 1, true);
connected_socket = socket(AF_UNIX, SOCK_DGRAM, 0);
non_connected_socket = socket(AF_UNIX, SOCK_DGRAM, 0);
diff --git a/tools/testing/selftests/landlock/scoped_signal_test.c b/tools/testing/selftests/landlock/scoped_signal_test.c
index d8bf33417619..8d1e1dc89c43 100644
--- a/tools/testing/selftests/landlock/scoped_signal_test.c
+++ b/tools/testing/selftests/landlock/scoped_signal_test.c
@@ -463,7 +463,7 @@ TEST_F(fown, sigurg_socket)
pid_t child;
memset(&server_address, 0, sizeof(server_address));
- set_unix_address(&server_address, 0);
+ set_unix_address(&server_address, 0, true);
ASSERT_EQ(0, pipe2(pipe_parent, O_CLOEXEC));
ASSERT_EQ(0, pipe2(pipe_child, O_CLOEXEC));
--
2.52.0
^ permalink raw reply related
* [PATCH 5/6] selftests/landlock: Repurpose scoped_abstract_unix_test.c for pathname sockets too.
From: Tingmao Wang @ 2025-12-28 12:45 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, linux-security-module
In-Reply-To: <cover.1766925301.git.m@maowtm.org>
Since there is very little difference between abstract and pathname
sockets in terms of testing of the scoped access checks (the only
difference is in which scope bit control which form of socket), it makes
sense to reuse the existing test for both type of sockets. Therefore, we
rename scoped_abstract_unix_test.c to scoped_unix_test.c and extend the
scoped_domains test to test pathname (i.e. non-abstract) sockets too.
Since we can't change the variant data of scoped_domains (as it is defined
in the shared .h file), we do this by extracting the actual test code into
a function, and call it from different test cases.
Also extend scoped_audit (this time we can use variants) to test both
abstract and pathname sockets. For pathname sockets, audit_log_lsm_data
will produce path="..." (or hex if path contains control characters) with
absolute paths from the dentry, so we need to construct the escaped regex
for the real path like in fs_test.
Signed-off-by: Tingmao Wang <m@maowtm.org>
---
...bstract_unix_test.c => scoped_unix_test.c} | 256 ++++++++++++++----
1 file changed, 206 insertions(+), 50 deletions(-)
rename tools/testing/selftests/landlock/{scoped_abstract_unix_test.c => scoped_unix_test.c} (81%)
diff --git a/tools/testing/selftests/landlock/scoped_abstract_unix_test.c b/tools/testing/selftests/landlock/scoped_unix_test.c
similarity index 81%
rename from tools/testing/selftests/landlock/scoped_abstract_unix_test.c
rename to tools/testing/selftests/landlock/scoped_unix_test.c
index 4a790e2d387d..669418c97509 100644
--- a/tools/testing/selftests/landlock/scoped_abstract_unix_test.c
+++ b/tools/testing/selftests/landlock/scoped_unix_test.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Landlock tests - Abstract UNIX socket
+ * Landlock tests - Scoped access checks for UNIX socket (abstract and
+ * pathname)
*
* Copyright © 2024 Tahera Fahimi <fahimitahera@gmail.com>
*/
@@ -19,6 +20,7 @@
#include <sys/un.h>
#include <sys/wait.h>
#include <unistd.h>
+#include <stdlib.h>
#include "audit.h"
#include "common.h"
@@ -47,7 +49,8 @@ static void create_fs_domain(struct __test_metadata *const _metadata)
FIXTURE(scoped_domains)
{
- struct service_fixture stream_address, dgram_address;
+ struct service_fixture stream_address_abstract, dgram_address_abstract,
+ stream_address_pathname, dgram_address_pathname;
};
#include "scoped_base_variants.h"
@@ -56,27 +59,62 @@ FIXTURE_SETUP(scoped_domains)
{
drop_caps(_metadata);
- memset(&self->stream_address, 0, sizeof(self->stream_address));
- memset(&self->dgram_address, 0, sizeof(self->dgram_address));
- set_unix_address(&self->stream_address, 0, true);
- set_unix_address(&self->dgram_address, 1, true);
+ ASSERT_EQ(0, mkdir(PATHNAME_UNIX_SOCK_DIR, 0700));
+
+ memset(&self->stream_address_abstract, 0,
+ sizeof(self->stream_address_abstract));
+ memset(&self->dgram_address_abstract, 0,
+ sizeof(self->dgram_address_abstract));
+ memset(&self->stream_address_pathname, 0,
+ sizeof(self->stream_address_pathname));
+ memset(&self->dgram_address_pathname, 0,
+ sizeof(self->dgram_address_pathname));
+ set_unix_address(&self->stream_address_abstract, 0, true);
+ set_unix_address(&self->dgram_address_abstract, 1, true);
+ set_unix_address(&self->stream_address_pathname, 0, false);
+ set_unix_address(&self->dgram_address_pathname, 1, false);
+}
+
+/* Remove @path if it exists */
+int remove_path(const char *path)
+{
+ if (unlink(path) == -1) {
+ if (errno != ENOENT)
+ return -errno;
+ }
+ return 0;
}
FIXTURE_TEARDOWN(scoped_domains)
{
+ EXPECT_EQ(0, remove_path(self->stream_address_pathname.unix_addr.sun_path));
+ EXPECT_EQ(0, remove_path(self->dgram_address_pathname.unix_addr.sun_path));
+ EXPECT_EQ(0, rmdir(PATHNAME_UNIX_SOCK_DIR));
}
/*
* Test unix_stream_connect() and unix_may_send() for a child connecting to its
* parent, when they have scoped domain or no domain.
*/
-TEST_F(scoped_domains, connect_to_parent)
+static void test_connect_to_parent(struct __test_metadata *const _metadata,
+ FIXTURE_DATA(scoped_domains) * self,
+ const FIXTURE_VARIANT(scoped_domains) *
+ variant,
+ const bool abstract)
{
pid_t child;
bool can_connect_to_parent;
int status;
int pipe_parent[2];
int stream_server, dgram_server;
+ const __u16 scope = abstract ? LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET :
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
+ const struct service_fixture *stream_address =
+ abstract ? &self->stream_address_abstract :
+ &self->stream_address_pathname;
+ const struct service_fixture *dgram_address =
+ abstract ? &self->dgram_address_abstract :
+ &self->dgram_address_pathname;
/*
* can_connect_to_parent is true if a child process can connect to its
@@ -87,8 +125,7 @@ TEST_F(scoped_domains, connect_to_parent)
ASSERT_EQ(0, pipe2(pipe_parent, O_CLOEXEC));
if (variant->domain_both) {
- create_scoped_domain(_metadata,
- LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
if (!__test_passed(_metadata))
return;
}
@@ -102,8 +139,7 @@ TEST_F(scoped_domains, connect_to_parent)
EXPECT_EQ(0, close(pipe_parent[1]));
if (variant->domain_child)
- create_scoped_domain(
- _metadata, LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
stream_client = socket(AF_UNIX, SOCK_STREAM, 0);
ASSERT_LE(0, stream_client);
@@ -113,8 +149,8 @@ TEST_F(scoped_domains, connect_to_parent)
/* Waits for the server. */
ASSERT_EQ(1, read(pipe_parent[0], &buf_child, 1));
- err = connect(stream_client, &self->stream_address.unix_addr,
- self->stream_address.unix_addr_len);
+ err = connect(stream_client, &stream_address->unix_addr,
+ stream_address->unix_addr_len);
if (can_connect_to_parent) {
EXPECT_EQ(0, err);
} else {
@@ -123,8 +159,8 @@ TEST_F(scoped_domains, connect_to_parent)
}
EXPECT_EQ(0, close(stream_client));
- err = connect(dgram_client, &self->dgram_address.unix_addr,
- self->dgram_address.unix_addr_len);
+ err = connect(dgram_client, &dgram_address->unix_addr,
+ dgram_address->unix_addr_len);
if (can_connect_to_parent) {
EXPECT_EQ(0, err);
} else {
@@ -137,17 +173,16 @@ TEST_F(scoped_domains, connect_to_parent)
}
EXPECT_EQ(0, close(pipe_parent[0]));
if (variant->domain_parent)
- create_scoped_domain(_metadata,
- LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
stream_server = socket(AF_UNIX, SOCK_STREAM, 0);
ASSERT_LE(0, stream_server);
dgram_server = socket(AF_UNIX, SOCK_DGRAM, 0);
ASSERT_LE(0, dgram_server);
- ASSERT_EQ(0, bind(stream_server, &self->stream_address.unix_addr,
- self->stream_address.unix_addr_len));
- ASSERT_EQ(0, bind(dgram_server, &self->dgram_address.unix_addr,
- self->dgram_address.unix_addr_len));
+ ASSERT_EQ(0, bind(stream_server, &stream_address->unix_addr,
+ stream_address->unix_addr_len));
+ ASSERT_EQ(0, bind(dgram_server, &dgram_address->unix_addr,
+ dgram_address->unix_addr_len));
ASSERT_EQ(0, listen(stream_server, backlog));
/* Signals to child that the parent is listening. */
@@ -166,7 +201,11 @@ TEST_F(scoped_domains, connect_to_parent)
* Test unix_stream_connect() and unix_may_send() for a parent connecting to
* its child, when they have scoped domain or no domain.
*/
-TEST_F(scoped_domains, connect_to_child)
+static void test_connect_to_child(struct __test_metadata *const _metadata,
+ FIXTURE_DATA(scoped_domains) * self,
+ const FIXTURE_VARIANT(scoped_domains) *
+ variant,
+ const bool abstract)
{
pid_t child;
bool can_connect_to_child;
@@ -174,6 +213,14 @@ TEST_F(scoped_domains, connect_to_child)
int pipe_child[2], pipe_parent[2];
char buf;
int stream_client, dgram_client;
+ const __u16 scope = abstract ? LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET :
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
+ const struct service_fixture *stream_address =
+ abstract ? &self->stream_address_abstract :
+ &self->stream_address_pathname;
+ const struct service_fixture *dgram_address =
+ abstract ? &self->dgram_address_abstract :
+ &self->dgram_address_pathname;
/*
* can_connect_to_child is true if a parent process can connect to its
@@ -185,8 +232,7 @@ TEST_F(scoped_domains, connect_to_child)
ASSERT_EQ(0, pipe2(pipe_child, O_CLOEXEC));
ASSERT_EQ(0, pipe2(pipe_parent, O_CLOEXEC));
if (variant->domain_both) {
- create_scoped_domain(_metadata,
- LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
if (!__test_passed(_metadata))
return;
}
@@ -199,8 +245,7 @@ TEST_F(scoped_domains, connect_to_child)
EXPECT_EQ(0, close(pipe_parent[1]));
EXPECT_EQ(0, close(pipe_child[0]));
if (variant->domain_child)
- create_scoped_domain(
- _metadata, LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
/* Waits for the parent to be in a domain, if any. */
ASSERT_EQ(1, read(pipe_parent[0], &buf, 1));
@@ -209,11 +254,10 @@ TEST_F(scoped_domains, connect_to_child)
ASSERT_LE(0, stream_server);
dgram_server = socket(AF_UNIX, SOCK_DGRAM, 0);
ASSERT_LE(0, dgram_server);
- ASSERT_EQ(0,
- bind(stream_server, &self->stream_address.unix_addr,
- self->stream_address.unix_addr_len));
- ASSERT_EQ(0, bind(dgram_server, &self->dgram_address.unix_addr,
- self->dgram_address.unix_addr_len));
+ ASSERT_EQ(0, bind(stream_server, &stream_address->unix_addr,
+ stream_address->unix_addr_len));
+ ASSERT_EQ(0, bind(dgram_server, &dgram_address->unix_addr,
+ dgram_address->unix_addr_len));
ASSERT_EQ(0, listen(stream_server, backlog));
/* Signals to the parent that child is listening. */
@@ -230,8 +274,7 @@ TEST_F(scoped_domains, connect_to_child)
EXPECT_EQ(0, close(pipe_parent[0]));
if (variant->domain_parent)
- create_scoped_domain(_metadata,
- LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
/* Signals that the parent is in a domain, if any. */
ASSERT_EQ(1, write(pipe_parent[1], ".", 1));
@@ -243,11 +286,11 @@ TEST_F(scoped_domains, connect_to_child)
/* Waits for the child to listen */
ASSERT_EQ(1, read(pipe_child[0], &buf, 1));
- err_stream = connect(stream_client, &self->stream_address.unix_addr,
- self->stream_address.unix_addr_len);
+ err_stream = connect(stream_client, &stream_address->unix_addr,
+ stream_address->unix_addr_len);
errno_stream = errno;
- err_dgram = connect(dgram_client, &self->dgram_address.unix_addr,
- self->dgram_address.unix_addr_len);
+ err_dgram = connect(dgram_client, &dgram_address->unix_addr,
+ dgram_address->unix_addr_len);
errno_dgram = errno;
if (can_connect_to_child) {
EXPECT_EQ(0, err_stream);
@@ -268,19 +311,79 @@ TEST_F(scoped_domains, connect_to_child)
_metadata->exit_code = KSFT_FAIL;
}
+/*
+ * Test unix_stream_connect() and unix_may_send() for a child connecting to its
+ * parent, when they have scoped domain or no domain.
+ */
+TEST_F(scoped_domains, abstract_connect_to_parent)
+{
+ test_connect_to_parent(_metadata, self, variant, true);
+}
+
+/*
+ * Test unix_stream_connect() and unix_may_send() for a parent connecting to
+ * its child, when they have scoped domain or no domain.
+ */
+TEST_F(scoped_domains, abstract_connect_to_child)
+{
+ test_connect_to_child(_metadata, self, variant, true);
+}
+
+/*
+ * Test unix_stream_connect() and unix_may_send() for a child connecting to its
+ * parent with pathname sockets.
+ */
+TEST_F(scoped_domains, pathname_connect_to_parent)
+{
+ test_connect_to_parent(_metadata, self, variant, false);
+}
+
+/*
+ * Test unix_stream_connect() and unix_may_send() for a parent connecting to
+ * its child with pathname sockets.
+ */
+TEST_F(scoped_domains, pathname_connect_to_child)
+{
+ test_connect_to_child(_metadata, self, variant, false);
+}
+
FIXTURE(scoped_audit)
{
- struct service_fixture dgram_address;
+ struct service_fixture dgram_address_abstract, dgram_address_pathname;
struct audit_filter audit_filter;
int audit_fd;
};
+FIXTURE_VARIANT(scoped_audit)
+{
+ const bool abstract_socket;
+};
+
+// clang-format off
+FIXTURE_VARIANT_ADD(scoped_audit, abstract_socket)
+{
+ // clang-format on
+ .abstract_socket = true,
+};
+
+// clang-format off
+FIXTURE_VARIANT_ADD(scoped_audit, pathname_socket)
+{
+ // clang-format on
+ .abstract_socket = false,
+};
+
FIXTURE_SETUP(scoped_audit)
{
disable_caps(_metadata);
- memset(&self->dgram_address, 0, sizeof(self->dgram_address));
- set_unix_address(&self->dgram_address, 1, true);
+ ASSERT_EQ(0, mkdir(PATHNAME_UNIX_SOCK_DIR, 0700));
+ memset(&self->dgram_address_abstract, 0,
+ sizeof(self->dgram_address_abstract));
+ memset(&self->dgram_address_pathname, 0,
+ sizeof(self->dgram_address_pathname));
+ set_unix_address(&self->dgram_address_abstract, 1, true);
+ set_unix_address(&self->dgram_address_pathname, 1, false);
set_cap(_metadata, CAP_AUDIT_CONTROL);
self->audit_fd = audit_init_with_exe_filter(&self->audit_filter);
@@ -291,6 +394,8 @@ FIXTURE_SETUP(scoped_audit)
FIXTURE_TEARDOWN_PARENT(scoped_audit)
{
EXPECT_EQ(0, audit_cleanup(-1, NULL));
+ EXPECT_EQ(0, remove_path(self->dgram_address_pathname.unix_addr.sun_path));
+ EXPECT_EQ(0, rmdir(PATHNAME_UNIX_SOCK_DIR));
}
/* python -c 'print(b"\0selftests-landlock-abstract-unix-".hex().upper())' */
@@ -308,6 +413,12 @@ TEST_F(scoped_audit, connect_to_child)
char buf;
int dgram_client;
struct audit_records records;
+ struct service_fixture *const dgram_address =
+ variant->abstract_socket ? &self->dgram_address_abstract :
+ &self->dgram_address_pathname;
+ size_t log_match_remaining = 500;
+ char log_match[log_match_remaining];
+ char *log_match_cursor = log_match;
/* Makes sure there is no superfluous logged records. */
EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
@@ -330,8 +441,8 @@ TEST_F(scoped_audit, connect_to_child)
dgram_server = socket(AF_UNIX, SOCK_DGRAM, 0);
ASSERT_LE(0, dgram_server);
- ASSERT_EQ(0, bind(dgram_server, &self->dgram_address.unix_addr,
- self->dgram_address.unix_addr_len));
+ ASSERT_EQ(0, bind(dgram_server, &dgram_address->unix_addr,
+ dgram_address->unix_addr_len));
/* Signals to the parent that child is listening. */
ASSERT_EQ(1, write(pipe_child[1], ".", 1));
@@ -345,7 +456,9 @@ TEST_F(scoped_audit, connect_to_child)
EXPECT_EQ(0, close(pipe_child[1]));
EXPECT_EQ(0, close(pipe_parent[0]));
- create_scoped_domain(_metadata, LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata,
+ LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET);
/* Signals that the parent is in a domain, if any. */
ASSERT_EQ(1, write(pipe_parent[1], ".", 1));
@@ -355,19 +468,62 @@ TEST_F(scoped_audit, connect_to_child)
/* Waits for the child to listen */
ASSERT_EQ(1, read(pipe_child[0], &buf, 1));
- err_dgram = connect(dgram_client, &self->dgram_address.unix_addr,
- self->dgram_address.unix_addr_len);
+ err_dgram = connect(dgram_client, &dgram_address->unix_addr,
+ dgram_address->unix_addr_len);
EXPECT_EQ(-1, err_dgram);
EXPECT_EQ(EPERM, errno);
- EXPECT_EQ(
- 0,
- audit_match_record(
- self->audit_fd, AUDIT_LANDLOCK_ACCESS,
+ if (variant->abstract_socket) {
+ log_match_cursor = stpncpy(
+ log_match,
REGEX_LANDLOCK_PREFIX
" blockers=scope\\.abstract_unix_socket path=" ABSTRACT_SOCKET_PATH_PREFIX
"[0-9A-F]\\+$",
- NULL));
+ log_match_remaining);
+ log_match_remaining =
+ sizeof(log_match) - (log_match_cursor - log_match);
+ ASSERT_NE(0, log_match_remaining);
+ } else {
+ /*
+ * It is assumed that absolute_path does not contain control
+ * characters nor spaces, see audit_string_contains_control().
+ */
+ char *absolute_path =
+ realpath(dgram_address->unix_addr.sun_path, NULL);
+
+ EXPECT_NE(NULL, absolute_path)
+ {
+ TH_LOG("realpath() failed: %s", strerror(errno));
+ return;
+ }
+
+ log_match_cursor =
+ stpncpy(log_match,
+ REGEX_LANDLOCK_PREFIX
+ " blockers=scope\\.pathname_unix_socket path=\"",
+ log_match_remaining);
+ log_match_remaining =
+ sizeof(log_match) - (log_match_cursor - log_match);
+ ASSERT_NE(0, log_match_remaining);
+ log_match_cursor = regex_escape(absolute_path, log_match_cursor,
+ log_match_remaining);
+ free(absolute_path);
+ if (log_match_cursor < 0) {
+ TH_LOG("regex_escape() failed (buffer too small)");
+ return;
+ }
+ log_match_remaining =
+ sizeof(log_match) - (log_match_cursor - log_match);
+ ASSERT_NE(0, log_match_remaining);
+ log_match_cursor =
+ stpncpy(log_match_cursor, "\"$", log_match_remaining);
+ log_match_remaining =
+ sizeof(log_match) - (log_match_cursor - log_match);
+ ASSERT_NE(0, log_match_remaining);
+ }
+
+ EXPECT_EQ(0, audit_match_record(self->audit_fd, AUDIT_LANDLOCK_ACCESS,
+ log_match, NULL));
ASSERT_EQ(1, write(pipe_parent[1], ".", 1));
EXPECT_EQ(0, close(dgram_client));
--
2.52.0
^ permalink raw reply related
* [PATCH 6/6] selftests/landlock: Add pathname socket variants for more tests
From: Tingmao Wang @ 2025-12-28 12:45 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, linux-security-module
In-Reply-To: <cover.1766925301.git.m@maowtm.org>
While this produces a lot of change, it does allow us to "simultaneously"
test both abstract and pathname UNIX sockets with reletively little code
duplication, since they are really similar.
Tests touched: scoped_vs_unscoped, outside_socket,
various_address_sockets, datagram_sockets, self_connect.
Signed-off-by: Tingmao Wang <m@maowtm.org>
---
.../selftests/landlock/scoped_unix_test.c | 599 ++++++++++++------
1 file changed, 395 insertions(+), 204 deletions(-)
diff --git a/tools/testing/selftests/landlock/scoped_unix_test.c b/tools/testing/selftests/landlock/scoped_unix_test.c
index 669418c97509..6d1541f77dbe 100644
--- a/tools/testing/selftests/landlock/scoped_unix_test.c
+++ b/tools/testing/selftests/landlock/scoped_unix_test.c
@@ -536,8 +536,12 @@ TEST_F(scoped_audit, connect_to_child)
FIXTURE(scoped_vs_unscoped)
{
- struct service_fixture parent_stream_address, parent_dgram_address,
- child_stream_address, child_dgram_address;
+ struct service_fixture parent_stream_address_abstract,
+ parent_dgram_address_abstract, child_stream_address_abstract,
+ child_dgram_address_abstract;
+ struct service_fixture parent_stream_address_pathname,
+ parent_dgram_address_pathname, child_stream_address_pathname,
+ child_dgram_address_pathname;
};
#include "scoped_multiple_domain_variants.h"
@@ -546,35 +550,75 @@ FIXTURE_SETUP(scoped_vs_unscoped)
{
drop_caps(_metadata);
- memset(&self->parent_stream_address, 0,
- sizeof(self->parent_stream_address));
- set_unix_address(&self->parent_stream_address, 0, true);
- memset(&self->parent_dgram_address, 0,
- sizeof(self->parent_dgram_address));
- set_unix_address(&self->parent_dgram_address, 1, true);
- memset(&self->child_stream_address, 0,
- sizeof(self->child_stream_address));
- set_unix_address(&self->child_stream_address, 2, true);
- memset(&self->child_dgram_address, 0,
- sizeof(self->child_dgram_address));
- set_unix_address(&self->child_dgram_address, 3, true);
+ ASSERT_EQ(0, mkdir(PATHNAME_UNIX_SOCK_DIR, 0700));
+
+ /* Abstract addresses. */
+ memset(&self->parent_stream_address_abstract, 0,
+ sizeof(self->parent_stream_address_abstract));
+ set_unix_address(&self->parent_stream_address_abstract, 0, true);
+ memset(&self->parent_dgram_address_abstract, 0,
+ sizeof(self->parent_dgram_address_abstract));
+ set_unix_address(&self->parent_dgram_address_abstract, 1, true);
+ memset(&self->child_stream_address_abstract, 0,
+ sizeof(self->child_stream_address_abstract));
+ set_unix_address(&self->child_stream_address_abstract, 2, true);
+ memset(&self->child_dgram_address_abstract, 0,
+ sizeof(self->child_dgram_address_abstract));
+ set_unix_address(&self->child_dgram_address_abstract, 3, true);
+
+ /* Pathname addresses. */
+ memset(&self->parent_stream_address_pathname, 0,
+ sizeof(self->parent_stream_address_pathname));
+ set_unix_address(&self->parent_stream_address_pathname, 4, false);
+ memset(&self->parent_dgram_address_pathname, 0,
+ sizeof(self->parent_dgram_address_pathname));
+ set_unix_address(&self->parent_dgram_address_pathname, 5, false);
+ memset(&self->child_stream_address_pathname, 0,
+ sizeof(self->child_stream_address_pathname));
+ set_unix_address(&self->child_stream_address_pathname, 6, false);
+ memset(&self->child_dgram_address_pathname, 0,
+ sizeof(self->child_dgram_address_pathname));
+ set_unix_address(&self->child_dgram_address_pathname, 7, false);
}
FIXTURE_TEARDOWN(scoped_vs_unscoped)
{
+ EXPECT_EQ(0, remove_path(self->parent_stream_address_pathname.unix_addr.sun_path));
+ EXPECT_EQ(0, remove_path(self->parent_dgram_address_pathname.unix_addr.sun_path));
+ EXPECT_EQ(0, remove_path(self->child_stream_address_pathname.unix_addr.sun_path));
+ EXPECT_EQ(0, remove_path(self->child_dgram_address_pathname.unix_addr.sun_path));
+ EXPECT_EQ(0, rmdir(PATHNAME_UNIX_SOCK_DIR));
}
/*
* Test unix_stream_connect and unix_may_send for parent, child and
* grand child processes when they can have scoped or non-scoped domains.
*/
-TEST_F(scoped_vs_unscoped, unix_scoping)
+static void test_scoped_vs_unscoped(
+ struct __test_metadata *const _metadata,
+ FIXTURE_DATA(scoped_vs_unscoped) * self,
+ const FIXTURE_VARIANT(scoped_vs_unscoped) * variant,
+ const bool abstract)
{
pid_t child;
int status;
bool can_connect_to_parent, can_connect_to_child;
int pipe_parent[2];
int stream_server_parent, dgram_server_parent;
+ const __u16 scope = abstract ? LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET :
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
+ const struct service_fixture *parent_stream_address =
+ abstract ? &self->parent_stream_address_abstract :
+ &self->parent_stream_address_pathname;
+ const struct service_fixture *parent_dgram_address =
+ abstract ? &self->parent_dgram_address_abstract :
+ &self->parent_dgram_address_pathname;
+ const struct service_fixture *child_stream_address =
+ abstract ? &self->child_stream_address_abstract :
+ &self->child_stream_address_pathname;
+ const struct service_fixture *child_dgram_address =
+ abstract ? &self->child_dgram_address_abstract :
+ &self->child_dgram_address_pathname;
can_connect_to_child = (variant->domain_grand_child != SCOPE_SANDBOX);
can_connect_to_parent = (can_connect_to_child &&
@@ -585,8 +629,7 @@ TEST_F(scoped_vs_unscoped, unix_scoping)
if (variant->domain_all == OTHER_SANDBOX)
create_fs_domain(_metadata);
else if (variant->domain_all == SCOPE_SANDBOX)
- create_scoped_domain(_metadata,
- LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
child = fork();
ASSERT_LE(0, child);
@@ -600,8 +643,7 @@ TEST_F(scoped_vs_unscoped, unix_scoping)
if (variant->domain_children == OTHER_SANDBOX)
create_fs_domain(_metadata);
else if (variant->domain_children == SCOPE_SANDBOX)
- create_scoped_domain(
- _metadata, LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
grand_child = fork();
ASSERT_LE(0, grand_child);
@@ -616,9 +658,7 @@ TEST_F(scoped_vs_unscoped, unix_scoping)
if (variant->domain_grand_child == OTHER_SANDBOX)
create_fs_domain(_metadata);
else if (variant->domain_grand_child == SCOPE_SANDBOX)
- create_scoped_domain(
- _metadata,
- LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
stream_client = socket(AF_UNIX, SOCK_STREAM, 0);
ASSERT_LE(0, stream_client);
@@ -626,15 +666,13 @@ TEST_F(scoped_vs_unscoped, unix_scoping)
ASSERT_LE(0, dgram_client);
ASSERT_EQ(1, read(pipe_child[0], &buf, 1));
- stream_err = connect(
- stream_client,
- &self->child_stream_address.unix_addr,
- self->child_stream_address.unix_addr_len);
+ stream_err = connect(stream_client,
+ &child_stream_address->unix_addr,
+ child_stream_address->unix_addr_len);
stream_errno = errno;
- dgram_err = connect(
- dgram_client,
- &self->child_dgram_address.unix_addr,
- self->child_dgram_address.unix_addr_len);
+ dgram_err = connect(dgram_client,
+ &child_dgram_address->unix_addr,
+ child_dgram_address->unix_addr_len);
dgram_errno = errno;
if (can_connect_to_child) {
EXPECT_EQ(0, stream_err);
@@ -653,14 +691,12 @@ TEST_F(scoped_vs_unscoped, unix_scoping)
ASSERT_EQ(1, read(pipe_parent[0], &buf, 1));
stream_err = connect(
- stream_client,
- &self->parent_stream_address.unix_addr,
- self->parent_stream_address.unix_addr_len);
+ stream_client, &parent_stream_address->unix_addr,
+ parent_stream_address->unix_addr_len);
stream_errno = errno;
dgram_err = connect(
- dgram_client,
- &self->parent_dgram_address.unix_addr,
- self->parent_dgram_address.unix_addr_len);
+ dgram_client, &parent_dgram_address->unix_addr,
+ parent_dgram_address->unix_addr_len);
dgram_errno = errno;
if (can_connect_to_parent) {
EXPECT_EQ(0, stream_err);
@@ -681,8 +717,7 @@ TEST_F(scoped_vs_unscoped, unix_scoping)
if (variant->domain_child == OTHER_SANDBOX)
create_fs_domain(_metadata);
else if (variant->domain_child == SCOPE_SANDBOX)
- create_scoped_domain(
- _metadata, LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
stream_server_child = socket(AF_UNIX, SOCK_STREAM, 0);
ASSERT_LE(0, stream_server_child);
@@ -690,11 +725,11 @@ TEST_F(scoped_vs_unscoped, unix_scoping)
ASSERT_LE(0, dgram_server_child);
ASSERT_EQ(0, bind(stream_server_child,
- &self->child_stream_address.unix_addr,
- self->child_stream_address.unix_addr_len));
- ASSERT_EQ(0, bind(dgram_server_child,
- &self->child_dgram_address.unix_addr,
- self->child_dgram_address.unix_addr_len));
+ &child_stream_address->unix_addr,
+ child_stream_address->unix_addr_len));
+ ASSERT_EQ(0,
+ bind(dgram_server_child, &child_dgram_address->unix_addr,
+ child_dgram_address->unix_addr_len));
ASSERT_EQ(0, listen(stream_server_child, backlog));
ASSERT_EQ(1, write(pipe_child[1], ".", 1));
@@ -708,19 +743,16 @@ TEST_F(scoped_vs_unscoped, unix_scoping)
if (variant->domain_parent == OTHER_SANDBOX)
create_fs_domain(_metadata);
else if (variant->domain_parent == SCOPE_SANDBOX)
- create_scoped_domain(_metadata,
- LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
stream_server_parent = socket(AF_UNIX, SOCK_STREAM, 0);
ASSERT_LE(0, stream_server_parent);
dgram_server_parent = socket(AF_UNIX, SOCK_DGRAM, 0);
ASSERT_LE(0, dgram_server_parent);
- ASSERT_EQ(0, bind(stream_server_parent,
- &self->parent_stream_address.unix_addr,
- self->parent_stream_address.unix_addr_len));
- ASSERT_EQ(0, bind(dgram_server_parent,
- &self->parent_dgram_address.unix_addr,
- self->parent_dgram_address.unix_addr_len));
+ ASSERT_EQ(0, bind(stream_server_parent, &parent_stream_address->unix_addr,
+ parent_stream_address->unix_addr_len));
+ ASSERT_EQ(0, bind(dgram_server_parent, &parent_dgram_address->unix_addr,
+ parent_dgram_address->unix_addr_len));
ASSERT_EQ(0, listen(stream_server_parent, backlog));
@@ -734,57 +766,119 @@ TEST_F(scoped_vs_unscoped, unix_scoping)
_metadata->exit_code = KSFT_FAIL;
}
+TEST_F(scoped_vs_unscoped, unix_scoping_abstract)
+{
+ test_scoped_vs_unscoped(_metadata, self, variant, true);
+}
+
+TEST_F(scoped_vs_unscoped, unix_scoping_pathname)
+{
+ test_scoped_vs_unscoped(_metadata, self, variant, false);
+}
+
FIXTURE(outside_socket)
{
- struct service_fixture address, transit_address;
+ struct service_fixture address_abstract, transit_address_abstract;
+ struct service_fixture address_pathname, transit_address_pathname;
};
FIXTURE_VARIANT(outside_socket)
{
const bool child_socket;
const int type;
+ const bool abstract;
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(outside_socket, abstract_allow_dgram_child) {
+ /* clang-format on */
+ .child_socket = true,
+ .type = SOCK_DGRAM,
+ .abstract = true,
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(outside_socket, abstract_deny_dgram_server) {
+ /* clang-format on */
+ .child_socket = false,
+ .type = SOCK_DGRAM,
+ .abstract = true,
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(outside_socket, abstract_allow_stream_child) {
+ /* clang-format on */
+ .child_socket = true,
+ .type = SOCK_STREAM,
+ .abstract = true,
};
/* clang-format off */
-FIXTURE_VARIANT_ADD(outside_socket, allow_dgram_child) {
+FIXTURE_VARIANT_ADD(outside_socket, abstract_deny_stream_server) {
+ /* clang-format on */
+ .child_socket = false,
+ .type = SOCK_STREAM,
+ .abstract = true,
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(outside_socket, pathname_allow_dgram_child) {
/* clang-format on */
.child_socket = true,
.type = SOCK_DGRAM,
+ .abstract = false,
};
/* clang-format off */
-FIXTURE_VARIANT_ADD(outside_socket, deny_dgram_server) {
+FIXTURE_VARIANT_ADD(outside_socket, pathname_deny_dgram_server) {
/* clang-format on */
.child_socket = false,
.type = SOCK_DGRAM,
+ .abstract = false,
};
/* clang-format off */
-FIXTURE_VARIANT_ADD(outside_socket, allow_stream_child) {
+FIXTURE_VARIANT_ADD(outside_socket, pathname_allow_stream_child) {
/* clang-format on */
.child_socket = true,
.type = SOCK_STREAM,
+ .abstract = false,
};
/* clang-format off */
-FIXTURE_VARIANT_ADD(outside_socket, deny_stream_server) {
+FIXTURE_VARIANT_ADD(outside_socket, pathname_deny_stream_server) {
/* clang-format on */
.child_socket = false,
.type = SOCK_STREAM,
+ .abstract = false,
};
FIXTURE_SETUP(outside_socket)
{
drop_caps(_metadata);
- memset(&self->transit_address, 0, sizeof(self->transit_address));
- set_unix_address(&self->transit_address, 0, true);
- memset(&self->address, 0, sizeof(self->address));
- set_unix_address(&self->address, 1, true);
+ ASSERT_EQ(0, mkdir(PATHNAME_UNIX_SOCK_DIR, 0700));
+
+ /* Abstract addresses. */
+ memset(&self->transit_address_abstract, 0,
+ sizeof(self->transit_address_abstract));
+ set_unix_address(&self->transit_address_abstract, 0, true);
+ memset(&self->address_abstract, 0, sizeof(self->address_abstract));
+ set_unix_address(&self->address_abstract, 1, true);
+
+ /* Pathname addresses. */
+ memset(&self->transit_address_pathname, 0,
+ sizeof(self->transit_address_pathname));
+ set_unix_address(&self->transit_address_pathname, 2, false);
+ memset(&self->address_pathname, 0, sizeof(self->address_pathname));
+ set_unix_address(&self->address_pathname, 3, false);
}
FIXTURE_TEARDOWN(outside_socket)
{
+ EXPECT_EQ(0, remove_path(self->transit_address_pathname.unix_addr.sun_path));
+ EXPECT_EQ(0, remove_path(self->address_pathname.unix_addr.sun_path));
+ EXPECT_EQ(0, rmdir(PATHNAME_UNIX_SOCK_DIR));
}
/*
@@ -798,6 +892,15 @@ TEST_F(outside_socket, socket_with_different_domain)
int pipe_child[2], pipe_parent[2];
char buf_parent;
int server_socket;
+ const __u16 scope = variant->abstract ?
+ LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET :
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
+ const struct service_fixture *transit_address =
+ variant->abstract ? &self->transit_address_abstract :
+ &self->transit_address_pathname;
+ const struct service_fixture *address =
+ variant->abstract ? &self->address_abstract :
+ &self->address_pathname;
ASSERT_EQ(0, pipe2(pipe_child, O_CLOEXEC));
ASSERT_EQ(0, pipe2(pipe_parent, O_CLOEXEC));
@@ -812,8 +915,7 @@ TEST_F(outside_socket, socket_with_different_domain)
EXPECT_EQ(0, close(pipe_child[0]));
/* Client always has a domain. */
- create_scoped_domain(_metadata,
- LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
if (variant->child_socket) {
int data_socket, passed_socket, stream_server;
@@ -823,8 +925,8 @@ TEST_F(outside_socket, socket_with_different_domain)
stream_server = socket(AF_UNIX, SOCK_STREAM, 0);
ASSERT_LE(0, stream_server);
ASSERT_EQ(0, bind(stream_server,
- &self->transit_address.unix_addr,
- self->transit_address.unix_addr_len));
+ &transit_address->unix_addr,
+ transit_address->unix_addr_len));
ASSERT_EQ(0, listen(stream_server, backlog));
ASSERT_EQ(1, write(pipe_child[1], ".", 1));
data_socket = accept(stream_server, NULL, NULL);
@@ -839,8 +941,8 @@ TEST_F(outside_socket, socket_with_different_domain)
/* Waits for parent signal for connection. */
ASSERT_EQ(1, read(pipe_parent[0], &buf_child, 1));
- err = connect(client_socket, &self->address.unix_addr,
- self->address.unix_addr_len);
+ err = connect(client_socket, &address->unix_addr,
+ address->unix_addr_len);
if (variant->child_socket) {
EXPECT_EQ(0, err);
} else {
@@ -859,9 +961,8 @@ TEST_F(outside_socket, socket_with_different_domain)
ASSERT_LE(0, client_child);
ASSERT_EQ(1, read(pipe_child[0], &buf_parent, 1));
- ASSERT_EQ(0, connect(client_child,
- &self->transit_address.unix_addr,
- self->transit_address.unix_addr_len));
+ ASSERT_EQ(0, connect(client_child, &transit_address->unix_addr,
+ transit_address->unix_addr_len));
server_socket = recv_fd(client_child);
EXPECT_EQ(0, close(client_child));
} else {
@@ -870,10 +971,10 @@ TEST_F(outside_socket, socket_with_different_domain)
ASSERT_LE(0, server_socket);
/* Server always has a domain. */
- create_scoped_domain(_metadata, LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
- ASSERT_EQ(0, bind(server_socket, &self->address.unix_addr,
- self->address.unix_addr_len));
+ ASSERT_EQ(0,
+ bind(server_socket, &address->unix_addr, address->unix_addr_len));
if (variant->type == SOCK_STREAM)
ASSERT_EQ(0, listen(server_socket, backlog));
@@ -888,52 +989,85 @@ TEST_F(outside_socket, socket_with_different_domain)
_metadata->exit_code = KSFT_FAIL;
}
-static const char stream_path[] = TMP_DIR "/stream.sock";
-static const char dgram_path[] = TMP_DIR "/dgram.sock";
-
/* clang-format off */
-FIXTURE(various_address_sockets) {};
+FIXTURE(various_address_sockets) {
+ struct service_fixture stream_pathname_addr, dgram_pathname_addr;
+ struct service_fixture stream_abstract_addr, dgram_abstract_addr;
+};
/* clang-format on */
-FIXTURE_VARIANT(various_address_sockets)
-{
- const int domain;
+/*
+ * Test all 4 combinations of abstract and pathname socket scope bits,
+ * plus a case with no Landlock domain at all.
+ */
+/* clang-format off */
+FIXTURE_VARIANT(various_address_sockets) {
+ /* clang-format on */
+ const __u16 scope_bits;
+ const bool no_sandbox;
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(various_address_sockets, scope_abstract) {
+ /* clang-format on */
+ .scope_bits = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET,
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(various_address_sockets, scope_pathname) {
+ /* clang-format on */
+ .scope_bits = LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET,
};
/* clang-format off */
-FIXTURE_VARIANT_ADD(various_address_sockets, pathname_socket_scoped_domain) {
+FIXTURE_VARIANT_ADD(various_address_sockets, scope_both) {
/* clang-format on */
- .domain = SCOPE_SANDBOX,
+ .scope_bits = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET,
};
/* clang-format off */
-FIXTURE_VARIANT_ADD(various_address_sockets, pathname_socket_other_domain) {
+FIXTURE_VARIANT_ADD(various_address_sockets, scope_none) {
/* clang-format on */
- .domain = OTHER_SANDBOX,
+ .scope_bits = 0,
};
/* clang-format off */
-FIXTURE_VARIANT_ADD(various_address_sockets, pathname_socket_no_domain) {
+FIXTURE_VARIANT_ADD(various_address_sockets, no_domain) {
/* clang-format on */
- .domain = NO_SANDBOX,
+ .no_sandbox = true,
};
FIXTURE_SETUP(various_address_sockets)
{
drop_caps(_metadata);
- umask(0077);
- ASSERT_EQ(0, mkdir(TMP_DIR, 0700));
+ ASSERT_EQ(0, mkdir(PATHNAME_UNIX_SOCK_DIR, 0700));
+
+ memset(&self->stream_pathname_addr, 0, sizeof(self->stream_pathname_addr));
+ set_unix_address(&self->stream_pathname_addr, 0, false);
+ memset(&self->dgram_pathname_addr, 0, sizeof(self->dgram_pathname_addr));
+ set_unix_address(&self->dgram_pathname_addr, 1, false);
+
+ memset(&self->stream_abstract_addr, 0, sizeof(self->stream_abstract_addr));
+ set_unix_address(&self->stream_abstract_addr, 2, true);
+ memset(&self->dgram_abstract_addr, 0, sizeof(self->dgram_abstract_addr));
+ set_unix_address(&self->dgram_abstract_addr, 3, true);
}
FIXTURE_TEARDOWN(various_address_sockets)
{
- EXPECT_EQ(0, unlink(stream_path));
- EXPECT_EQ(0, unlink(dgram_path));
- EXPECT_EQ(0, rmdir(TMP_DIR));
+ EXPECT_EQ(0, remove_path(self->stream_pathname_addr.unix_addr.sun_path));
+ EXPECT_EQ(0, remove_path(self->dgram_pathname_addr.unix_addr.sun_path));
+ EXPECT_EQ(0, rmdir(PATHNAME_UNIX_SOCK_DIR));
}
-TEST_F(various_address_sockets, scoped_pathname_sockets)
+/*
+ * Test interaction of various scope flags (controlled by variant->domain)
+ * with pathname and abstract sockets when connecting from a sandboxed
+ * child.
+ */
+TEST_F(various_address_sockets, scoped_sockets)
{
pid_t child;
int status;
@@ -942,25 +1076,10 @@ TEST_F(various_address_sockets, scoped_pathname_sockets)
int unnamed_sockets[2];
int stream_pathname_socket, dgram_pathname_socket,
stream_abstract_socket, dgram_abstract_socket, data_socket;
- struct service_fixture stream_abstract_addr, dgram_abstract_addr;
- struct sockaddr_un stream_pathname_addr = {
- .sun_family = AF_UNIX,
- };
- struct sockaddr_un dgram_pathname_addr = {
- .sun_family = AF_UNIX,
- };
-
- /* Pathname address. */
- snprintf(stream_pathname_addr.sun_path,
- sizeof(stream_pathname_addr.sun_path), "%s", stream_path);
- snprintf(dgram_pathname_addr.sun_path,
- sizeof(dgram_pathname_addr.sun_path), "%s", dgram_path);
-
- /* Abstract address. */
- memset(&stream_abstract_addr, 0, sizeof(stream_abstract_addr));
- set_unix_address(&stream_abstract_addr, 0, true);
- memset(&dgram_abstract_addr, 0, sizeof(dgram_abstract_addr));
- set_unix_address(&dgram_abstract_addr, 1, true);
+ bool pathname_restricted =
+ (variant->scope_bits & LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET);
+ bool abstract_restricted =
+ (variant->scope_bits & LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
/* Unnamed address for datagram socket. */
ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_DGRAM, 0, unnamed_sockets));
@@ -975,82 +1094,103 @@ TEST_F(various_address_sockets, scoped_pathname_sockets)
EXPECT_EQ(0, close(pipe_parent[1]));
EXPECT_EQ(0, close(unnamed_sockets[1]));
- if (variant->domain == SCOPE_SANDBOX)
- create_scoped_domain(
- _metadata, LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
- else if (variant->domain == OTHER_SANDBOX)
+ /* Create domain based on variant. */
+ if (variant->scope_bits)
+ create_scoped_domain(_metadata, variant->scope_bits);
+ else if (!variant->no_sandbox)
create_fs_domain(_metadata);
/* Waits for parent to listen. */
ASSERT_EQ(1, read(pipe_parent[0], &buf_child, 1));
EXPECT_EQ(0, close(pipe_parent[0]));
- /* Checks that we can send data through a datagram socket. */
+ /* Checks that we can send data through a unnamed socket. */
ASSERT_EQ(1, write(unnamed_sockets[0], "a", 1));
EXPECT_EQ(0, close(unnamed_sockets[0]));
/* Connects with pathname sockets. */
stream_pathname_socket = socket(AF_UNIX, SOCK_STREAM, 0);
ASSERT_LE(0, stream_pathname_socket);
- ASSERT_EQ(0,
- connect(stream_pathname_socket, &stream_pathname_addr,
- sizeof(stream_pathname_addr)));
- ASSERT_EQ(1, write(stream_pathname_socket, "b", 1));
+ err = connect(stream_pathname_socket,
+ &self->stream_pathname_addr.unix_addr,
+ self->stream_pathname_addr.unix_addr_len);
+ if (pathname_restricted) {
+ EXPECT_EQ(-1, err);
+ EXPECT_EQ(EPERM, errno);
+ } else {
+ EXPECT_EQ(0, err);
+ ASSERT_EQ(1, write(stream_pathname_socket, "b", 1));
+ }
EXPECT_EQ(0, close(stream_pathname_socket));
- /* Sends without connection. */
+ /* Sends without connection (pathname). */
dgram_pathname_socket = socket(AF_UNIX, SOCK_DGRAM, 0);
ASSERT_LE(0, dgram_pathname_socket);
err = sendto(dgram_pathname_socket, "c", 1, 0,
- &dgram_pathname_addr, sizeof(dgram_pathname_addr));
- EXPECT_EQ(1, err);
+ &self->dgram_pathname_addr.unix_addr,
+ self->dgram_pathname_addr.unix_addr_len);
+ if (pathname_restricted) {
+ EXPECT_EQ(-1, err);
+ EXPECT_EQ(EPERM, errno);
+ } else {
+ EXPECT_EQ(1, err);
+ }
+
+ /* Sends with connection (pathname). */
+ err = connect(dgram_pathname_socket,
+ &self->dgram_pathname_addr.unix_addr,
+ self->dgram_pathname_addr.unix_addr_len);
+ if (pathname_restricted) {
+ EXPECT_EQ(-1, err);
+ EXPECT_EQ(EPERM, errno);
+ } else {
+ EXPECT_EQ(0, err);
+ ASSERT_EQ(1, write(dgram_pathname_socket, "d", 1));
+ }
- /* Sends with connection. */
- ASSERT_EQ(0,
- connect(dgram_pathname_socket, &dgram_pathname_addr,
- sizeof(dgram_pathname_addr)));
- ASSERT_EQ(1, write(dgram_pathname_socket, "d", 1));
EXPECT_EQ(0, close(dgram_pathname_socket));
/* Connects with abstract sockets. */
stream_abstract_socket = socket(AF_UNIX, SOCK_STREAM, 0);
ASSERT_LE(0, stream_abstract_socket);
err = connect(stream_abstract_socket,
- &stream_abstract_addr.unix_addr,
- stream_abstract_addr.unix_addr_len);
- if (variant->domain == SCOPE_SANDBOX) {
+ &self->stream_abstract_addr.unix_addr,
+ self->stream_abstract_addr.unix_addr_len);
+ if (abstract_restricted) {
EXPECT_EQ(-1, err);
EXPECT_EQ(EPERM, errno);
} else {
EXPECT_EQ(0, err);
ASSERT_EQ(1, write(stream_abstract_socket, "e", 1));
}
+
EXPECT_EQ(0, close(stream_abstract_socket));
- /* Sends without connection. */
+ /* Sends without connection (abstract). */
dgram_abstract_socket = socket(AF_UNIX, SOCK_DGRAM, 0);
ASSERT_LE(0, dgram_abstract_socket);
err = sendto(dgram_abstract_socket, "f", 1, 0,
- &dgram_abstract_addr.unix_addr,
- dgram_abstract_addr.unix_addr_len);
- if (variant->domain == SCOPE_SANDBOX) {
+ &self->dgram_abstract_addr.unix_addr,
+ self->dgram_abstract_addr.unix_addr_len);
+ if (abstract_restricted) {
EXPECT_EQ(-1, err);
EXPECT_EQ(EPERM, errno);
} else {
EXPECT_EQ(1, err);
}
- /* Sends with connection. */
+ /* Sends with connection (abstract). */
err = connect(dgram_abstract_socket,
- &dgram_abstract_addr.unix_addr,
- dgram_abstract_addr.unix_addr_len);
- if (variant->domain == SCOPE_SANDBOX) {
+ &self->dgram_abstract_addr.unix_addr,
+ self->dgram_abstract_addr.unix_addr_len);
+ if (abstract_restricted) {
EXPECT_EQ(-1, err);
EXPECT_EQ(EPERM, errno);
} else {
EXPECT_EQ(0, err);
ASSERT_EQ(1, write(dgram_abstract_socket, "g", 1));
}
+
EXPECT_EQ(0, close(dgram_abstract_socket));
_exit(_metadata->exit_code);
@@ -1062,27 +1202,30 @@ TEST_F(various_address_sockets, scoped_pathname_sockets)
/* Sets up pathname servers. */
stream_pathname_socket = socket(AF_UNIX, SOCK_STREAM, 0);
ASSERT_LE(0, stream_pathname_socket);
- ASSERT_EQ(0, bind(stream_pathname_socket, &stream_pathname_addr,
- sizeof(stream_pathname_addr)));
+ ASSERT_EQ(0, bind(stream_pathname_socket,
+ &self->stream_pathname_addr.unix_addr,
+ self->stream_pathname_addr.unix_addr_len));
ASSERT_EQ(0, listen(stream_pathname_socket, backlog));
dgram_pathname_socket = socket(AF_UNIX, SOCK_DGRAM, 0);
ASSERT_LE(0, dgram_pathname_socket);
- ASSERT_EQ(0, bind(dgram_pathname_socket, &dgram_pathname_addr,
- sizeof(dgram_pathname_addr)));
+ ASSERT_EQ(0, bind(dgram_pathname_socket,
+ &self->dgram_pathname_addr.unix_addr,
+ self->dgram_pathname_addr.unix_addr_len));
/* Sets up abstract servers. */
stream_abstract_socket = socket(AF_UNIX, SOCK_STREAM, 0);
ASSERT_LE(0, stream_abstract_socket);
- ASSERT_EQ(0,
- bind(stream_abstract_socket, &stream_abstract_addr.unix_addr,
- stream_abstract_addr.unix_addr_len));
+ ASSERT_EQ(0, bind(stream_abstract_socket,
+ &self->stream_abstract_addr.unix_addr,
+ self->stream_abstract_addr.unix_addr_len));
+ ASSERT_EQ(0, listen(stream_abstract_socket, backlog));
dgram_abstract_socket = socket(AF_UNIX, SOCK_DGRAM, 0);
ASSERT_LE(0, dgram_abstract_socket);
- ASSERT_EQ(0, bind(dgram_abstract_socket, &dgram_abstract_addr.unix_addr,
- dgram_abstract_addr.unix_addr_len));
- ASSERT_EQ(0, listen(stream_abstract_socket, backlog));
+ ASSERT_EQ(0, bind(dgram_abstract_socket,
+ &self->dgram_abstract_addr.unix_addr,
+ self->dgram_abstract_addr.unix_addr_len));
ASSERT_EQ(1, write(pipe_parent[1], ".", 1));
EXPECT_EQ(0, close(pipe_parent[1]));
@@ -1092,24 +1235,31 @@ TEST_F(various_address_sockets, scoped_pathname_sockets)
ASSERT_EQ('a', buf_parent);
EXPECT_LE(0, close(unnamed_sockets[1]));
- /* Reads from pathname sockets. */
- data_socket = accept(stream_pathname_socket, NULL, NULL);
- ASSERT_LE(0, data_socket);
- ASSERT_EQ(1, read(data_socket, &buf_parent, sizeof(buf_parent)));
- ASSERT_EQ('b', buf_parent);
- EXPECT_EQ(0, close(data_socket));
- EXPECT_EQ(0, close(stream_pathname_socket));
+ if (!pathname_restricted) {
+ /*
+ * Reads from pathname sockets if we expect child to be able to
+ * send.
+ */
+ data_socket = accept(stream_pathname_socket, NULL, NULL);
+ ASSERT_LE(0, data_socket);
+ ASSERT_EQ(1,
+ read(data_socket, &buf_parent, sizeof(buf_parent)));
+ ASSERT_EQ('b', buf_parent);
+ EXPECT_EQ(0, close(data_socket));
- ASSERT_EQ(1,
- read(dgram_pathname_socket, &buf_parent, sizeof(buf_parent)));
- ASSERT_EQ('c', buf_parent);
- ASSERT_EQ(1,
- read(dgram_pathname_socket, &buf_parent, sizeof(buf_parent)));
- ASSERT_EQ('d', buf_parent);
- EXPECT_EQ(0, close(dgram_pathname_socket));
+ ASSERT_EQ(1, read(dgram_pathname_socket, &buf_parent,
+ sizeof(buf_parent)));
+ ASSERT_EQ('c', buf_parent);
+ ASSERT_EQ(1, read(dgram_pathname_socket, &buf_parent,
+ sizeof(buf_parent)));
+ ASSERT_EQ('d', buf_parent);
+ }
- if (variant->domain != SCOPE_SANDBOX) {
- /* Reads from abstract sockets if allowed to send. */
+ if (!abstract_restricted) {
+ /*
+ * Reads from abstract sockets if we expect child to be able to
+ * send.
+ */
data_socket = accept(stream_abstract_socket, NULL, NULL);
ASSERT_LE(0, data_socket);
ASSERT_EQ(1,
@@ -1125,30 +1275,73 @@ TEST_F(various_address_sockets, scoped_pathname_sockets)
ASSERT_EQ('g', buf_parent);
}
- /* Waits for all abstract socket tests. */
+ /* Waits for child to complete, and only close the socket afterwards. */
ASSERT_EQ(child, waitpid(child, &status, 0));
EXPECT_EQ(0, close(stream_abstract_socket));
EXPECT_EQ(0, close(dgram_abstract_socket));
+ EXPECT_EQ(0, close(stream_pathname_socket));
+ EXPECT_EQ(0, close(dgram_pathname_socket));
if (WIFSIGNALED(status) || !WIFEXITED(status) ||
WEXITSTATUS(status) != EXIT_SUCCESS)
_metadata->exit_code = KSFT_FAIL;
}
-TEST(datagram_sockets)
+/* Fixture for datagram_sockets and self_connect tests */
+FIXTURE(socket_type_test)
{
struct service_fixture connected_addr, non_connected_addr;
+};
+
+FIXTURE_VARIANT(socket_type_test)
+{
+ const bool abstract;
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(socket_type_test, abstract) {
+ /* clang-format on */
+ .abstract = true,
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(socket_type_test, pathname) {
+ /* clang-format on */
+ .abstract = false,
+};
+
+FIXTURE_SETUP(socket_type_test)
+{
+ drop_caps(_metadata);
+
+ if (!variant->abstract)
+ ASSERT_EQ(0, mkdir(PATHNAME_UNIX_SOCK_DIR, 0700));
+
+ memset(&self->connected_addr, 0, sizeof(self->connected_addr));
+ set_unix_address(&self->connected_addr, 0, variant->abstract);
+ memset(&self->non_connected_addr, 0, sizeof(self->non_connected_addr));
+ set_unix_address(&self->non_connected_addr, 1, variant->abstract);
+}
+
+FIXTURE_TEARDOWN(socket_type_test)
+{
+ if (!variant->abstract) {
+ EXPECT_EQ(0, remove_path(self->connected_addr.unix_addr.sun_path));
+ EXPECT_EQ(0, remove_path(self->non_connected_addr.unix_addr.sun_path));
+ EXPECT_EQ(0, rmdir(PATHNAME_UNIX_SOCK_DIR));
+ }
+}
+
+TEST_F(socket_type_test, datagram_sockets)
+{
int server_conn_socket, server_unconn_socket;
int pipe_parent[2], pipe_child[2];
int status;
char buf;
pid_t child;
-
- drop_caps(_metadata);
- memset(&connected_addr, 0, sizeof(connected_addr));
- set_unix_address(&connected_addr, 0, true);
- memset(&non_connected_addr, 0, sizeof(non_connected_addr));
- set_unix_address(&non_connected_addr, 1, true);
+ const __u16 scope = variant->abstract ?
+ LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET :
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
ASSERT_EQ(0, pipe2(pipe_parent, O_CLOEXEC));
ASSERT_EQ(0, pipe2(pipe_child, O_CLOEXEC));
@@ -1169,8 +1362,9 @@ TEST(datagram_sockets)
/* Waits for parent to listen. */
ASSERT_EQ(1, read(pipe_parent[0], &buf, 1));
ASSERT_EQ(0,
- connect(client_conn_socket, &connected_addr.unix_addr,
- connected_addr.unix_addr_len));
+ connect(client_conn_socket,
+ &self->connected_addr.unix_addr,
+ self->connected_addr.unix_addr_len));
/*
* Both connected and non-connected sockets can send data when
@@ -1178,13 +1372,12 @@ TEST(datagram_sockets)
*/
ASSERT_EQ(1, send(client_conn_socket, ".", 1, 0));
ASSERT_EQ(1, sendto(client_unconn_socket, ".", 1, 0,
- &non_connected_addr.unix_addr,
- non_connected_addr.unix_addr_len));
+ &self->non_connected_addr.unix_addr,
+ self->non_connected_addr.unix_addr_len));
ASSERT_EQ(1, write(pipe_child[1], ".", 1));
/* Scopes the domain. */
- create_scoped_domain(_metadata,
- LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
/*
* Connected socket sends data to the receiver, but the
@@ -1192,8 +1385,8 @@ TEST(datagram_sockets)
*/
ASSERT_EQ(1, send(client_conn_socket, ".", 1, 0));
ASSERT_EQ(-1, sendto(client_unconn_socket, ".", 1, 0,
- &non_connected_addr.unix_addr,
- non_connected_addr.unix_addr_len));
+ &self->non_connected_addr.unix_addr,
+ self->non_connected_addr.unix_addr_len));
ASSERT_EQ(EPERM, errno);
ASSERT_EQ(1, write(pipe_child[1], ".", 1));
@@ -1210,10 +1403,11 @@ TEST(datagram_sockets)
ASSERT_LE(0, server_conn_socket);
ASSERT_LE(0, server_unconn_socket);
- ASSERT_EQ(0, bind(server_conn_socket, &connected_addr.unix_addr,
- connected_addr.unix_addr_len));
- ASSERT_EQ(0, bind(server_unconn_socket, &non_connected_addr.unix_addr,
- non_connected_addr.unix_addr_len));
+ ASSERT_EQ(0, bind(server_conn_socket, &self->connected_addr.unix_addr,
+ self->connected_addr.unix_addr_len));
+ ASSERT_EQ(0, bind(server_unconn_socket,
+ &self->non_connected_addr.unix_addr,
+ self->non_connected_addr.unix_addr_len));
ASSERT_EQ(1, write(pipe_parent[1], ".", 1));
/* Waits for child to test. */
@@ -1238,52 +1432,49 @@ TEST(datagram_sockets)
_metadata->exit_code = KSFT_FAIL;
}
-TEST(self_connect)
+TEST_F(socket_type_test, self_connect)
{
- struct service_fixture connected_addr, non_connected_addr;
int connected_socket, non_connected_socket, status;
pid_t child;
-
- drop_caps(_metadata);
- memset(&connected_addr, 0, sizeof(connected_addr));
- set_unix_address(&connected_addr, 0, true);
- memset(&non_connected_addr, 0, sizeof(non_connected_addr));
- set_unix_address(&non_connected_addr, 1, true);
+ const __u16 scope = variant->abstract ?
+ LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET :
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
connected_socket = socket(AF_UNIX, SOCK_DGRAM, 0);
non_connected_socket = socket(AF_UNIX, SOCK_DGRAM, 0);
ASSERT_LE(0, connected_socket);
ASSERT_LE(0, non_connected_socket);
- ASSERT_EQ(0, bind(connected_socket, &connected_addr.unix_addr,
- connected_addr.unix_addr_len));
- ASSERT_EQ(0, bind(non_connected_socket, &non_connected_addr.unix_addr,
- non_connected_addr.unix_addr_len));
+ ASSERT_EQ(0, bind(connected_socket, &self->connected_addr.unix_addr,
+ self->connected_addr.unix_addr_len));
+ ASSERT_EQ(0, bind(non_connected_socket,
+ &self->non_connected_addr.unix_addr,
+ self->non_connected_addr.unix_addr_len));
child = fork();
ASSERT_LE(0, child);
if (child == 0) {
/* Child's domain is scoped. */
- create_scoped_domain(_metadata,
- LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
+ create_scoped_domain(_metadata, scope);
/*
* The child inherits the sockets, and cannot connect or
* send data to them.
*/
ASSERT_EQ(-1,
- connect(connected_socket, &connected_addr.unix_addr,
- connected_addr.unix_addr_len));
+ connect(connected_socket,
+ &self->connected_addr.unix_addr,
+ self->connected_addr.unix_addr_len));
ASSERT_EQ(EPERM, errno);
ASSERT_EQ(-1, sendto(connected_socket, ".", 1, 0,
- &connected_addr.unix_addr,
- connected_addr.unix_addr_len));
+ &self->connected_addr.unix_addr,
+ self->connected_addr.unix_addr_len));
ASSERT_EQ(EPERM, errno);
ASSERT_EQ(-1, sendto(non_connected_socket, ".", 1, 0,
- &non_connected_addr.unix_addr,
- non_connected_addr.unix_addr_len));
+ &self->non_connected_addr.unix_addr,
+ self->non_connected_addr.unix_addr_len));
ASSERT_EQ(EPERM, errno);
EXPECT_EQ(0, close(connected_socket));
--
2.52.0
^ permalink raw reply related
* Re: [PATCH 2/6] landlock: Implement LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
From: Justin Suess @ 2025-12-28 16:37 UTC (permalink / raw)
To: m; +Cc: demiobenour, fahimitahera, gnoack, hi, jannh,
linux-security-module, mic
In-Reply-To: <be315d8ff7544fd91bdb922e8afc7c8154e3594d.1766925301.git.m@maowtm.org>
On 12/28/25 07:45, Tingmao Wang wrote:
> Extend the existing abstract UNIX socket scoping to pathname sockets as
> well. Basically all of the logic is reused between the two types, just
> that pathname sockets scoping are controlled by another bit, and has its
> own audit request type (since the current one is named
> "abstract_unix_socket").
>
>
> Closes: https://github.com/landlock-lsm/linux/issues/51
> Signed-off-by: Tingmao Wang <m@maowtm.org>
> ---
>
> There is an argument that there should only really be one audit request
> type for both sockets, since the only difference is whether path= is
> followed by a normal path, or by a hex string starting with 00. But I'm
> not sure if we can change this at this point, so I have created a new
> request type.
>
> security/landlock/audit.c | 4 +++
> security/landlock/audit.h | 1 +
> security/landlock/task.c | 74 ++++++++++++++++++++++++++++++---------
> 3 files changed, 62 insertions(+), 17 deletions(-)
>
> diff --git a/security/landlock/audit.c b/security/landlock/audit.c
> index e899995f1fd5..0626cc553ab0 100644
> --- a/security/landlock/audit.c
> +++ b/security/landlock/audit.c
> @@ -75,6 +75,10 @@ get_blocker(const enum landlock_request_type type,
> WARN_ON_ONCE(access_bit != -1);
> return "scope.abstract_unix_socket";
>
> + case LANDLOCK_REQUEST_SCOPE_PATHNAME_UNIX_SOCKET:
> + WARN_ON_ONCE(access_bit != -1);
> + return "scope.pathname_unix_socket";
> +
> case LANDLOCK_REQUEST_SCOPE_SIGNAL:
> WARN_ON_ONCE(access_bit != -1);
> return "scope.signal";
> diff --git a/security/landlock/audit.h b/security/landlock/audit.h
> index 92428b7fc4d8..1c9ce8588102 100644
> --- a/security/landlock/audit.h
> +++ b/security/landlock/audit.h
> @@ -21,6 +21,7 @@ enum landlock_request_type {
> LANDLOCK_REQUEST_NET_ACCESS,
> LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET,
> LANDLOCK_REQUEST_SCOPE_SIGNAL,
> + LANDLOCK_REQUEST_SCOPE_PATHNAME_UNIX_SOCKET,
> };
>
> /*
> diff --git a/security/landlock/task.c b/security/landlock/task.c
> index 6dfcc1860d6e..9fbb0ada440b 100644
> --- a/security/landlock/task.c
> +++ b/security/landlock/task.c
> @@ -233,57 +233,84 @@ static bool domain_is_scoped(const struct landlock_ruleset *const client,
> return false;
> }
>
> +/**
> + * sock_is_scoped - Check if socket connect or send should be restricted
> + * based on scope controls.
> + *
> + * @other: The server socket.
> + * @domain: The client domain.
> + * @scope: The relevant scope bit to check (i.e. pathname or abstract).
> + *
> + * Returns: True if connect should be restricted, false otherwise.
> + */
> static bool sock_is_scoped(struct sock *const other,
> - const struct landlock_ruleset *const domain)
> + const struct landlock_ruleset *const domain,
> + access_mask_t scope)
> {
> const struct landlock_ruleset *dom_other;
>
> /* The credentials will not change. */
> lockdep_assert_held(&unix_sk(other)->lock);
> dom_other = landlock_cred(other->sk_socket->file->f_cred)->domain;
> - return domain_is_scoped(domain, dom_other,
> - LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET);
> + return domain_is_scoped(domain, dom_other, scope);
> }
>
> -static bool is_abstract_socket(struct sock *const sock)
> +static bool sock_addr_is_abstract(const struct unix_address *const addr)
Nit: From the name sock_addr_is_abstract, it's unclear without reading
the parameter that this function only works with unix sockets, when
socket is an overloaded term that can refer to other kinds of sockets
(e.g tcp/udp/raw).
Maybe is_unix_sock_addr_abstract? or unix_sock_addr_is_abstract?
>
> {
> - struct unix_address *addr = unix_sk(sock)->addr;
> -
> - if (!addr)
> - return false;
> -
> - if (addr->len >= offsetof(struct sockaddr_un, sun_path) + 1 &&
> + if (addr && addr->len >= offsetof(struct sockaddr_un, sun_path) + 1 &&
> addr->name->sun_path[0] == '\0')
> return true;
>
> return false;
> }
>
> +/* Allow us to quickly test if the current domain scopes any form of socket */
> static const struct access_masks unix_scope = {
> - .scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET,
> + .scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
> + LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET,
> };
>
> +/*
> + * UNIX sockets can have three types of addresses: pathname (a filesystem path),
> + * unnamed (not bound to an address), and abstract (sun_path[0] is '\0').
> + * Unnamed sockets include those created with socketpair() and unbound sockets.
> + * We do not restrict unnamed sockets since they have no address to identify.
> + */
> static int hook_unix_stream_connect(struct sock *const sock,
> struct sock *const other,
> struct sock *const newsk)
> {
> size_t handle_layer;
> + access_mask_t scope;
> + enum landlock_request_type request_type;
> const struct landlock_cred_security *const subject =
> landlock_get_applicable_subject(current_cred(), unix_scope,
> &handle_layer);
> + const struct unix_address *addr;
>
> /* Quick return for non-landlocked tasks. */
> if (!subject)
> return 0;
>
> - if (!is_abstract_socket(other))
> + addr = unix_sk(other)->addr;
> + /* Unnamed sockets are not restricted. */
> + if (!addr)
> return 0;
>
> - if (!sock_is_scoped(other, subject->domain))
> + if (sock_addr_is_abstract(addr)) {
> + scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET;
> + request_type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET;
> + } else {
> + /* Pathname socket. */
> + scope = LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
> + request_type = LANDLOCK_REQUEST_SCOPE_PATHNAME_UNIX_SOCKET;
> + }
> +
> + if (!sock_is_scoped(other, subject->domain, scope))
> return 0;
>
> landlock_log_denial(subject, &(struct landlock_request) {
> - .type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET,
> + .type = request_type,
> .audit = {
> .type = LSM_AUDIT_DATA_NET,
> .u.net = &(struct lsm_network_audit) {
> @@ -299,9 +326,12 @@ static int hook_unix_may_send(struct socket *const sock,
> struct socket *const other)
> {
> size_t handle_layer;
> + access_mask_t scope;
> + enum landlock_request_type request_type;
> const struct landlock_cred_security *const subject =
> landlock_get_applicable_subject(current_cred(), unix_scope,
> &handle_layer);
> + const struct unix_address *addr;
>
> if (!subject)
> return 0;
> @@ -313,14 +343,24 @@ static int hook_unix_may_send(struct socket *const sock,
> if (unix_peer(sock->sk) == other->sk)
> return 0;
>
> - if (!is_abstract_socket(other->sk))
> + addr = unix_sk(other->sk)->addr;
> + /* Unnamed sockets are not restricted. */
> + if (!addr)
> return 0;
>
> - if (!sock_is_scoped(other->sk, subject->domain))
> + if (sock_addr_is_abstract(addr)) {
> + scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET;
> + request_type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET;
> + } else {
> + scope = LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
> + request_type = LANDLOCK_REQUEST_SCOPE_PATHNAME_UNIX_SOCKET;
> + }
> +
> + if (!sock_is_scoped(other->sk, subject->domain, scope))
> return 0;
>
> landlock_log_denial(subject, &(struct landlock_request) {
> - .type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET,
> + .type = request_type,
> .audit = {
> .type = LSM_AUDIT_DATA_NET,
> .u.net = &(struct lsm_network_audit) {
^ permalink raw reply
* Re: [PATCH 2/6] landlock: Implement LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
From: Mickaël Salaün @ 2025-12-28 18:15 UTC (permalink / raw)
To: Tingmao Wang
Cc: Günther Noack, Demi Marie Obenour, Alyssa Ross, Jann Horn,
Tahera Fahimi, linux-security-module, Justin Suess
In-Reply-To: <be315d8ff7544fd91bdb922e8afc7c8154e3594d.1766925301.git.m@maowtm.org>
On Sun, Dec 28, 2025 at 12:45:41PM +0000, Tingmao Wang wrote:
> Extend the existing abstract UNIX socket scoping to pathname sockets as
> well. Basically all of the logic is reused between the two types, just
> that pathname sockets scoping are controlled by another bit, and has its
> own audit request type (since the current one is named
> "abstract_unix_socket").
>
> Closes: https://github.com/landlock-lsm/linux/issues/51
> Signed-off-by: Tingmao Wang <m@maowtm.org>
Great, thanks!
> ---
>
> There is an argument that there should only really be one audit request
> type for both sockets, since the only difference is whether path= is
> followed by a normal path, or by a hex string starting with 00. But I'm
> not sure if we can change this at this point, so I have created a new
> request type.
It is the correct approach to add a dedicated request type, which
enables to filter on it, and doesn't have performance impact.
>
> security/landlock/audit.c | 4 +++
> security/landlock/audit.h | 1 +
> security/landlock/task.c | 74 ++++++++++++++++++++++++++++++---------
> 3 files changed, 62 insertions(+), 17 deletions(-)
> diff --git a/security/landlock/task.c b/security/landlock/task.c
> index 6dfcc1860d6e..9fbb0ada440b 100644
> --- a/security/landlock/task.c
> +++ b/security/landlock/task.c
> +/*
> + * UNIX sockets can have three types of addresses: pathname (a filesystem path),
> + * unnamed (not bound to an address), and abstract (sun_path[0] is '\0').
> + * Unnamed sockets include those created with socketpair() and unbound sockets.
> + * We do not restrict unnamed sockets since they have no address to identify.
> + */
> static int hook_unix_stream_connect(struct sock *const sock,
> struct sock *const other,
> struct sock *const newsk)
> {
> size_t handle_layer;
> + access_mask_t scope;
> + enum landlock_request_type request_type;
> const struct landlock_cred_security *const subject =
> landlock_get_applicable_subject(current_cred(), unix_scope,
> &handle_layer);
> + const struct unix_address *addr;
>
> /* Quick return for non-landlocked tasks. */
> if (!subject)
> return 0;
>
> - if (!is_abstract_socket(other))
> + addr = unix_sk(other)->addr;
> + /* Unnamed sockets are not restricted. */
> + if (!addr)
> return 0;
>
> - if (!sock_is_scoped(other, subject->domain))
> + if (sock_addr_is_abstract(addr)) {
> + scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET;
> + request_type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET;
> + } else {
> + /* Pathname socket. */
> + scope = LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
> + request_type = LANDLOCK_REQUEST_SCOPE_PATHNAME_UNIX_SOCKET;
> + }
> +
> + if (!sock_is_scoped(other, subject->domain, scope))
> return 0;
We should be able to factor out this hunk for both hooks, and then also
fold is_abstract_socket() in this new helper.
>
> landlock_log_denial(subject, &(struct landlock_request) {
> - .type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET,
> + .type = request_type,
> .audit = {
> .type = LSM_AUDIT_DATA_NET,
> .u.net = &(struct lsm_network_audit) {
> @@ -299,9 +326,12 @@ static int hook_unix_may_send(struct socket *const sock,
> struct socket *const other)
> {
> size_t handle_layer;
> + access_mask_t scope;
> + enum landlock_request_type request_type;
> const struct landlock_cred_security *const subject =
> landlock_get_applicable_subject(current_cred(), unix_scope,
> &handle_layer);
> + const struct unix_address *addr;
>
> if (!subject)
> return 0;
> @@ -313,14 +343,24 @@ static int hook_unix_may_send(struct socket *const sock,
> if (unix_peer(sock->sk) == other->sk)
> return 0;
>
> - if (!is_abstract_socket(other->sk))
> + addr = unix_sk(other->sk)->addr;
> + /* Unnamed sockets are not restricted. */
> + if (!addr)
> return 0;
>
> - if (!sock_is_scoped(other->sk, subject->domain))
> + if (sock_addr_is_abstract(addr)) {
> + scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET;
> + request_type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET;
> + } else {
> + scope = LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET;
> + request_type = LANDLOCK_REQUEST_SCOPE_PATHNAME_UNIX_SOCKET;
> + }
> +
> + if (!sock_is_scoped(other->sk, subject->domain, scope))
> return 0;
>
> landlock_log_denial(subject, &(struct landlock_request) {
> - .type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET,
> + .type = request_type,
> .audit = {
> .type = LSM_AUDIT_DATA_NET,
> .u.net = &(struct lsm_network_audit) {
> --
> 2.52.0
>
^ permalink raw reply
* Re: [PATCH 3/5] Documentation/landlock: Fix missing case for ABI 6 in downgrade example
From: Mickaël Salaün @ 2025-12-28 18:16 UTC (permalink / raw)
To: Tingmao Wang
Cc: Günther Noack, Günther Noack, Samasth Norway Ananda,
linux-security-module
In-Reply-To: <1175b37d065b49520cbc335a9a2d501513a6c6ef.1766885035.git.m@maowtm.org>
The subject for documentation should just start with "landlock: "
On Sun, Dec 28, 2025 at 01:27:33AM +0000, Tingmao Wang wrote:
> Note that this code is different from the one in sandboxer.c since
> sandboxer won't ever add LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF and
> LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF.
A more complet patch was sent a few days ago:
https://lore.kernel.org/r/3e21551d-24c3-459f-8cee-4d85c97c0120@oracle.com
>
> Fixes: 12bfcda73ac2 ("landlock: Add LANDLOCK_RESTRICT_SELF_LOG_*_EXEC_* flags")
Unless required by other parts of the patch, there is no need to
backport documentation changes, so there should not be any Fixes tag.
> Signed-off-by: Tingmao Wang <m@maowtm.org>
> ---
> Documentation/userspace-api/landlock.rst | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst
> index 1d0c2c15c22e..903d2ad11852 100644
> --- a/Documentation/userspace-api/landlock.rst
> +++ b/Documentation/userspace-api/landlock.rst
> @@ -127,6 +127,12 @@ version, and only use the available subset of access rights:
> /* Removes LANDLOCK_SCOPE_* for ABI < 6 */
> ruleset_attr.scoped &= ~(LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
> LANDLOCK_SCOPE_SIGNAL);
> + __attribute__((fallthrough));
> + case 6:
> + /* Removes LANDLOCK_RESTRICT_SELF_LOG_* for ABI < 7 */
> + supported_restrict_flags &= ~(LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON |
> + LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF |
> + LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF);
As Günther pointed out, this switch/case might not be needed for this
part of the documentation.
> }
>
> This enables the creation of an inclusive ruleset that will contain our rules.
> --
> 2.52.0
>
>
^ permalink raw reply
* Re: [PATCH 0/5] Landlock: Test, comment and doc improvements
From: Mickaël Salaün @ 2025-12-28 18:16 UTC (permalink / raw)
To: Tingmao Wang
Cc: Günther Noack, Samasth Norway Ananda, linux-security-module
In-Reply-To: <cover.1766885035.git.m@maowtm.org>
On Sun, Dec 28, 2025 at 01:27:30AM +0000, Tingmao Wang wrote:
> Hi,
>
> This series contains various unrelated improvements I stashed while
> working on pathname Unix socket scopes (I will send the series for that
> tomorrow). Only test/comment/doc changes.
Thanks!
>
> I was planning to include this in the upcoming Unix socket scope series
> but I thought maybe it would be better to send them separately, as they
> would be unrelated to the main topic of that series.
Yes, that's better.
>
> Tingmao Wang (5):
> selftests/landlock: Fix typo in fs_test
Applied
> selftests/landlock: Fix missing semicolon
Applied
> Documentation/landlock: Fix missing case for ABI 6 in downgrade
> example
Not applied, see review.
> selftests/landlock: Use scoped_base_variants.h for ptrace_test
Applied
> landlock: Improve the comment for domain_is_scoped
Applied with cosmetic changes.
>
> Documentation/userspace-api/landlock.rst | 6 +
> security/landlock/task.c | 9 +-
> tools/testing/selftests/landlock/fs_test.c | 4 +-
> .../testing/selftests/landlock/ptrace_test.c | 154 +-----------------
> .../landlock/scoped_abstract_unix_test.c | 2 +-
> .../selftests/landlock/scoped_base_variants.h | 9 +-
> 6 files changed, 26 insertions(+), 158 deletions(-)
>
>
> base-commit: 161db1810f3625e97ab414908dbcf4b2ab73c309
> --
> 2.52.0
>
>
^ permalink raw reply
* Re: [RFC PATCH 5/5] landlock: Improve the comment for domain_is_scoped
From: Mickaël Salaün @ 2025-12-28 18:16 UTC (permalink / raw)
To: Tingmao Wang
Cc: Günther Noack, Samasth Norway Ananda, linux-security-module,
Tahera Fahimi
In-Reply-To: <06393bc18aee5bc278df5ef31c64a05b742ebc10.1766885035.git.m@maowtm.org>
On Sun, Dec 28, 2025 at 01:27:35AM +0000, Tingmao Wang wrote:
> Currently it is not obvious what "scoped" mean, and the fact that the
> function returns true when access should be denied is slightly surprising
> and in need of documentation.
>
> Cc: Tahera Fahimi <fahimitahera@gmail.com>
> Signed-off-by: Tingmao Wang <m@maowtm.org>
> ---
>
> Open to discussion on whether this actually explains it better.
>
> security/landlock/task.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/security/landlock/task.c b/security/landlock/task.c
> index bf4ed15a7f01..6dfcc1860d6e 100644
> --- a/security/landlock/task.c
> +++ b/security/landlock/task.c
> @@ -166,15 +166,16 @@ static int hook_ptrace_traceme(struct task_struct *const parent)
> }
>
> /**
> - * domain_is_scoped - Checks if the client domain is scoped in the same
> - * domain as the server.
> + * domain_is_scoped - Check if an interaction from a client/sender to a
> + * server/receiver should be restricted based on scope controls.
> *
> * @client: IPC sender domain.
> * @server: IPC receiver domain.
> * @scope: The scope restriction criteria.
> *
> - * Returns: True if the @client domain is scoped to access the @server,
> - * unless the @server is also scoped in the same domain as @client.
> + * Returns: True if the @server is in a different domain from @client, and
> + * the @client domain is scoped to access the @server (i.e. access
> + * should be denied).
I removed the "the" and the heading spaces:
*
- * Returns: True if the @client domain is scoped to access the @server,
- * unless the @server is also scoped in the same domain as @client.
+ * Returns: True if @server is in a different domain from @client, and @client
+ * is scoped to access @server (i.e. access should be denied).
*/
> */
> static bool domain_is_scoped(const struct landlock_ruleset *const client,
> const struct landlock_ruleset *const server,
> --
> 2.52.0
>
^ permalink raw reply
* Re: commoncap KUnit tests v4
From: Ryan Foster @ 2025-12-28 19:45 UTC (permalink / raw)
To: linux-security-module; +Cc: linux-kernel, paul, serge
In-Reply-To: <20251204215610.148342-1-foster.ryan.r@gmail.com>
Hi all,
I've updated the patch after noticing the dependency on CONFIG_USER_NS=y
Thanks,
Ryan
^ permalink raw reply
* [PATCH v4] security: Add KUnit tests for kuid_root_in_ns and vfsuid_root_in_currentns
From: Ryan Foster @ 2025-12-28 19:45 UTC (permalink / raw)
To: linux-security-module; +Cc: linux-kernel, paul, serge, Ryan Foster
In-Reply-To: <20251228194838.32214-1-foster.ryan.r@gmail.com>
Add comprehensive KUnit tests for the namespace-related capability
functions that Serge Hallyn refactored in commit 9891d2f79a9f
("Clarify the rootid_owns_currentns").
The tests verify:
- Basic functionality: UID 0 in init namespace, invalid vfsuid,
non-zero UIDs
- Actual namespace traversal: Creating user namespaces with different
UID mappings where uid 0 maps to different kuids (e.g., 1000, 2000,
3000)
- Hierarchy traversal: Testing multiple nested namespaces to verify
correct namespace hierarchy traversal
This addresses the feedback to "test the actual functionality" by
creating real user namespaces with different values for the
namespace's uid 0, rather than just basic input validation.
The test file is included at the end of commoncap.c when
CONFIG_SECURITY_COMMONCAP_KUNIT_TEST is enabled, following the
standard kernel pattern (e.g., scsi_lib.c, ext4/mballoc.c). This
allows tests to access static functions in the same compilation unit
without modifying production code based on test configuration.
The tests require CONFIG_USER_NS to be enabled since they rely on user
namespace mapping functionality. The Kconfig dependency ensures the
tests only build when this requirement is met.
All 7 tests pass:
- test_vfsuid_root_in_currentns_init_ns
- test_vfsuid_root_in_currentns_invalid
- test_vfsuid_root_in_currentns_nonzero
- test_kuid_root_in_ns_init_ns_uid0
- test_kuid_root_in_ns_init_ns_nonzero
- test_kuid_root_in_ns_with_mapping
- test_kuid_root_in_ns_with_different_mappings
Updated MAINTAINER capabilities to include commoncap test
Signed-off-by: Ryan Foster <foster.ryan.r@gmail.com>
---
MAINTAINERS | 1 +
security/Kconfig | 17 +++
security/commoncap.c | 4 +
security/commoncap_test.c | 290 ++++++++++++++++++++++++++++++++++++++
4 files changed, 312 insertions(+)
create mode 100644 security/commoncap_test.c
diff --git a/MAINTAINERS b/MAINTAINERS
index c0030e126fc8..6f162c736dfb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5682,6 +5682,7 @@ F: include/trace/events/capability.h
F: include/uapi/linux/capability.h
F: kernel/capability.c
F: security/commoncap.c
+F: security/commoncap_test.c
CAPELLA MICROSYSTEMS LIGHT SENSOR DRIVER
M: Kevin Tsai <ktsai@capellamicro.com>
diff --git a/security/Kconfig b/security/Kconfig
index 285f284dfcac..f47975284aab 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -284,6 +284,23 @@ config LSM
If unsure, leave this as the default.
+config SECURITY_COMMONCAP_KUNIT_TEST
+ bool "Build KUnit tests for commoncap" if !KUNIT_ALL_TESTS
+ depends on KUNIT && USER_NS
+ default KUNIT_ALL_TESTS
+ help
+ This builds the commoncap KUnit tests.
+
+ KUnit tests run during boot and output the results to the debug log
+ in TAP format (https://testanything.org/). Only useful for kernel devs
+ running KUnit test harness and are not for inclusion into a
+ production build.
+
+ For more information on KUnit and unit tests in general please refer
+ to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+ If unsure, say N.
+
source "security/Kconfig.hardening"
endmenu
diff --git a/security/commoncap.c b/security/commoncap.c
index 8a23dfab7fac..3399535808fe 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -1521,3 +1521,7 @@ DEFINE_LSM(capability) = {
};
#endif /* CONFIG_SECURITY */
+
+#ifdef CONFIG_SECURITY_COMMONCAP_KUNIT_TEST
+#include "commoncap_test.c"
+#endif
diff --git a/security/commoncap_test.c b/security/commoncap_test.c
new file mode 100644
index 000000000000..1088364a54e6
--- /dev/null
+++ b/security/commoncap_test.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * KUnit tests for commoncap.c security functions
+ *
+ * Tests for security-critical functions in the capability subsystem,
+ * particularly namespace-related capability checks.
+ */
+
+#include <kunit/test.h>
+#include <linux/user_namespace.h>
+#include <linux/uidgid.h>
+#include <linux/cred.h>
+#include <linux/mnt_idmapping.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/refcount.h>
+
+#ifdef CONFIG_SECURITY_COMMONCAP_KUNIT_TEST
+
+/* Functions are static in commoncap.c, but we can call them since we're
+ * included in the same compilation unit when tests are enabled.
+ */
+
+/**
+ * test_vfsuid_root_in_currentns_init_ns - Test vfsuid_root_in_currentns with init ns
+ *
+ * Verifies that UID 0 in the init namespace correctly owns the current
+ * namespace when running in init_user_ns.
+ *
+ * @test: KUnit test context
+ */
+static void test_vfsuid_root_in_currentns_init_ns(struct kunit *test)
+{
+ vfsuid_t vfsuid;
+ kuid_t kuid;
+
+ /* Create UID 0 in init namespace */
+ kuid = KUIDT_INIT(0);
+ vfsuid = VFSUIDT_INIT(kuid);
+
+ /* In init namespace, UID 0 should own current namespace */
+ KUNIT_EXPECT_TRUE(test, vfsuid_root_in_currentns(vfsuid));
+}
+
+/**
+ * test_vfsuid_root_in_currentns_invalid - Test vfsuid_root_in_currentns with invalid vfsuid
+ *
+ * Verifies that an invalid vfsuid correctly returns false.
+ *
+ * @test: KUnit test context
+ */
+static void test_vfsuid_root_in_currentns_invalid(struct kunit *test)
+{
+ vfsuid_t invalid_vfsuid;
+
+ /* Use the predefined invalid vfsuid */
+ invalid_vfsuid = INVALID_VFSUID;
+
+ /* Invalid vfsuid should return false */
+ KUNIT_EXPECT_FALSE(test, vfsuid_root_in_currentns(invalid_vfsuid));
+}
+
+/**
+ * test_vfsuid_root_in_currentns_nonzero - Test vfsuid_root_in_currentns with non-zero UID
+ *
+ * Verifies that a non-zero UID correctly returns false.
+ *
+ * @test: KUnit test context
+ */
+static void test_vfsuid_root_in_currentns_nonzero(struct kunit *test)
+{
+ vfsuid_t vfsuid;
+ kuid_t kuid;
+
+ /* Create a non-zero UID */
+ kuid = KUIDT_INIT(1000);
+ vfsuid = VFSUIDT_INIT(kuid);
+
+ /* Non-zero UID should return false */
+ KUNIT_EXPECT_FALSE(test, vfsuid_root_in_currentns(vfsuid));
+}
+
+/**
+ * test_kuid_root_in_ns_init_ns_uid0 - Test kuid_root_in_ns with init namespace and UID 0
+ *
+ * Verifies that kuid_root_in_ns correctly identifies UID 0 in init namespace.
+ * This tests the core namespace traversal logic. In init namespace, UID 0
+ * maps to itself, so it should own the namespace.
+ *
+ * @test: KUnit test context
+ */
+static void test_kuid_root_in_ns_init_ns_uid0(struct kunit *test)
+{
+ kuid_t kuid;
+ struct user_namespace *init_ns;
+
+ kuid = KUIDT_INIT(0);
+ init_ns = &init_user_ns;
+
+ /* UID 0 should own init namespace */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(kuid, init_ns));
+}
+
+/**
+ * test_kuid_root_in_ns_init_ns_nonzero - Test kuid_root_in_ns with init namespace and non-zero UID
+ *
+ * Verifies that kuid_root_in_ns correctly rejects non-zero UIDs in init namespace.
+ * Only UID 0 should own a namespace.
+ *
+ * @test: KUnit test context
+ */
+static void test_kuid_root_in_ns_init_ns_nonzero(struct kunit *test)
+{
+ kuid_t kuid;
+ struct user_namespace *init_ns;
+
+ kuid = KUIDT_INIT(1000);
+ init_ns = &init_user_ns;
+
+ /* Non-zero UID should not own namespace */
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(kuid, init_ns));
+}
+
+/**
+ * create_test_user_ns_with_mapping - Create a mock user namespace with UID mapping
+ *
+ * Creates a minimal user namespace structure for testing where uid 0 in the
+ * namespace maps to a specific kuid in the parent namespace.
+ *
+ * @test: KUnit test context
+ * @parent_ns: Parent namespace (typically init_user_ns)
+ * @mapped_kuid: The kuid that uid 0 in this namespace maps to in parent
+ *
+ * Returns: Pointer to allocated namespace, or NULL on failure
+ */
+static struct user_namespace *create_test_user_ns_with_mapping(struct kunit *test,
+ struct user_namespace *parent_ns,
+ kuid_t mapped_kuid)
+{
+ struct user_namespace *ns;
+ struct uid_gid_extent extent;
+
+ /* Allocate a test namespace - use kzalloc to zero all fields */
+ ns = kunit_kzalloc(test, sizeof(*ns), GFP_KERNEL);
+ if (!ns)
+ return NULL;
+
+ /* Initialize basic namespace structure fields */
+ ns->parent = parent_ns;
+ ns->level = parent_ns ? parent_ns->level + 1 : 0;
+ ns->owner = mapped_kuid;
+ ns->group = KGIDT_INIT(0);
+
+ /* Initialize ns_common structure */
+ refcount_set(&ns->ns.__ns_ref, 1);
+ ns->ns.inum = 0; /* Mock inum */
+
+ /* Set up uid mapping: uid 0 in this namespace maps to mapped_kuid in parent
+ * Format: first (uid in ns) : lower_first (kuid in parent) : count
+ * So: uid 0 in ns -> kuid mapped_kuid in parent
+ * This means from_kuid(ns, mapped_kuid) returns 0
+ */
+ extent.first = 0; /* uid 0 in this namespace */
+ extent.lower_first = __kuid_val(mapped_kuid); /* maps to this kuid in parent */
+ extent.count = 1;
+
+ ns->uid_map.extent[0] = extent;
+ ns->uid_map.nr_extents = 1;
+
+ /* Set up gid mapping: gid 0 maps to gid 0 in parent (simplified) */
+ extent.first = 0;
+ extent.lower_first = 0;
+ extent.count = 1;
+
+ ns->gid_map.extent[0] = extent;
+ ns->gid_map.nr_extents = 1;
+
+ return ns;
+}
+
+/**
+ * test_kuid_root_in_ns_with_mapping - Test kuid_root_in_ns with namespace where uid 0
+ * maps to different kuid
+ *
+ * Creates a user namespace where uid 0 maps to kuid 1000 in the parent namespace.
+ * Verifies that kuid_root_in_ns correctly identifies kuid 1000 as owning the namespace.
+ *
+ * Note: kuid_root_in_ns walks up the namespace hierarchy, so it checks the current
+ * namespace first, then parent, then parent's parent, etc. So:
+ * - kuid 1000 owns test_ns because from_kuid(test_ns, 1000) == 0
+ * - kuid 0 also owns test_ns because from_kuid(init_user_ns, 0) == 0
+ * (checked in parent)
+ *
+ * This tests the actual functionality as requested: creating namespaces with
+ * different values for the namespace's uid 0.
+ *
+ * @test: KUnit test context
+ */
+static void test_kuid_root_in_ns_with_mapping(struct kunit *test)
+{
+ struct user_namespace *test_ns;
+ struct user_namespace *parent_ns;
+ kuid_t mapped_kuid, other_kuid;
+
+ parent_ns = &init_user_ns;
+ mapped_kuid = KUIDT_INIT(1000);
+ other_kuid = KUIDT_INIT(2000);
+
+ test_ns = create_test_user_ns_with_mapping(test, parent_ns, mapped_kuid);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_ns);
+
+ /* kuid 1000 should own test_ns because it maps to uid 0 in test_ns */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(mapped_kuid, test_ns));
+
+ /* kuid 0 should also own test_ns (checked via parent init_user_ns) */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), test_ns));
+
+ /* Other kuids should not own test_ns */
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(other_kuid, test_ns));
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(500), test_ns));
+}
+
+/**
+ * test_kuid_root_in_ns_with_different_mappings - Test with multiple namespaces
+ *
+ * Creates multiple user namespaces with different UID mappings to verify
+ * that kuid_root_in_ns correctly handles different namespace hierarchies.
+ *
+ * Since kuid_root_in_ns walks up the hierarchy, kuids that map to 0 in init_user_ns
+ * will own all namespaces, while kuids that only map to 0 in specific namespaces
+ * will only own those namespaces and their children.
+ *
+ * @test: KUnit test context
+ */
+static void test_kuid_root_in_ns_with_different_mappings(struct kunit *test)
+{
+ struct user_namespace *ns1, *ns2, *ns3;
+
+ /* Create ns1 where uid 0 maps to kuid 1000 */
+ ns1 = create_test_user_ns_with_mapping(test, &init_user_ns, KUIDT_INIT(1000));
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ns1);
+
+ /* Create ns2 where uid 0 maps to kuid 2000 */
+ ns2 = create_test_user_ns_with_mapping(test, &init_user_ns, KUIDT_INIT(2000));
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ns2);
+
+ /* Create ns3 as a child of ns1 where uid 0 maps to kuid 3000 */
+ ns3 = create_test_user_ns_with_mapping(test, ns1, KUIDT_INIT(3000));
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ns3);
+
+ /* Test ns1: kuid 1000 owns it, kuid 0 owns it (via parent), kuid 2000 does not */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(1000), ns1));
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), ns1));
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(2000), ns1));
+
+ /* Test ns2: kuid 2000 owns it, kuid 0 owns it (via parent), kuid 1000 does not */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(2000), ns2));
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), ns2));
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(1000), ns2));
+
+ /* Test ns3: kuid 3000 owns it, kuid 1000 owns it (via parent ns1),
+ * kuid 0 owns it (via init_user_ns), kuid 2000 does not
+ */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(3000), ns3));
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(1000), ns3));
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), ns3));
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(2000), ns3));
+}
+
+static struct kunit_case commoncap_test_cases[] = {
+ KUNIT_CASE(test_vfsuid_root_in_currentns_init_ns),
+ KUNIT_CASE(test_vfsuid_root_in_currentns_invalid),
+ KUNIT_CASE(test_vfsuid_root_in_currentns_nonzero),
+ KUNIT_CASE(test_kuid_root_in_ns_init_ns_uid0),
+ KUNIT_CASE(test_kuid_root_in_ns_init_ns_nonzero),
+ KUNIT_CASE(test_kuid_root_in_ns_with_mapping),
+ KUNIT_CASE(test_kuid_root_in_ns_with_different_mappings),
+ {}
+};
+
+static struct kunit_suite commoncap_test_suite = {
+ .name = "commoncap",
+ .test_cases = commoncap_test_cases,
+};
+
+kunit_test_suite(commoncap_test_suite);
+
+MODULE_LICENSE("GPL");
+
+#endif /* CONFIG_SECURITY_COMMONCAP_KUNIT_TEST */
--
2.52.0
^ permalink raw reply related
* Re: [PATCH 3/6] samples/landlock: Support LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
From: Demi Marie Obenour @ 2025-12-29 2:48 UTC (permalink / raw)
To: Tingmao Wang, Mickaël Salaün
Cc: Günther Noack, Alyssa Ross, Jann Horn, Tahera Fahimi,
linux-security-module
In-Reply-To: <625fa7da41fa6abdebac9e48e824232465504c9f.1766925301.git.m@maowtm.org>
[-- Attachment #1.1.1: Type: text/plain, Size: 880 bytes --]
On 12/28/25 07:45, Tingmao Wang wrote:
> Signed-off-by: Tingmao Wang <m@maowtm.org>
>
> ---
>
> I've decided to use "u" as the character to control this scope bit since
> it stands for (normal) Unix sockets. Imo using "p" or "n" would make it less
> clear / memorable. Open to suggestions.
>
> Also, open to suggestion whether socket scoping (pathname and abstract)
> should be enabled by default, if LL_SCOPED is not set. This would break
> backward compatibility, but maybe we shouldn't guarentee backward
> compatibility of this sandboxer in the first place, and almost all cases
> of Landlock usage would want socket scoping.
I think almost all uses of Landlock would want to either scope pathname
sockets, or else only allow an allowlist of them to be accessed.
The latter is not currently possible.
--
Sincerely,
Demi Marie Obenour (she/her/hers)
[-- Attachment #1.1.2: OpenPGP public key --]
[-- Type: application/pgp-keys, Size: 7253 bytes --]
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
^ permalink raw reply
* Re: [PATCH v4] security: Add KUnit tests for kuid_root_in_ns and vfsuid_root_in_currentns
From: Serge E. Hallyn @ 2025-12-29 4:14 UTC (permalink / raw)
To: Ryan Foster; +Cc: linux-security-module, linux-kernel, paul, serge
In-Reply-To: <20251228194838.32214-2-foster.ryan.r@gmail.com>
On Sun, Dec 28, 2025 at 11:45:37AM -0800, Ryan Foster wrote:
> Add comprehensive KUnit tests for the namespace-related capability
> functions that Serge Hallyn refactored in commit 9891d2f79a9f
> ("Clarify the rootid_owns_currentns").
>
> The tests verify:
> - Basic functionality: UID 0 in init namespace, invalid vfsuid,
> non-zero UIDs
> - Actual namespace traversal: Creating user namespaces with different
> UID mappings where uid 0 maps to different kuids (e.g., 1000, 2000,
> 3000)
> - Hierarchy traversal: Testing multiple nested namespaces to verify
> correct namespace hierarchy traversal
>
> This addresses the feedback to "test the actual functionality" by
> creating real user namespaces with different values for the
> namespace's uid 0, rather than just basic input validation.
>
> The test file is included at the end of commoncap.c when
> CONFIG_SECURITY_COMMONCAP_KUNIT_TEST is enabled, following the
> standard kernel pattern (e.g., scsi_lib.c, ext4/mballoc.c). This
Thank you for pointing this out, as it seemed odd to me.
> allows tests to access static functions in the same compilation unit
> without modifying production code based on test configuration.
>
> The tests require CONFIG_USER_NS to be enabled since they rely on user
> namespace mapping functionality. The Kconfig dependency ensures the
> tests only build when this requirement is met.
>
> All 7 tests pass:
> - test_vfsuid_root_in_currentns_init_ns
> - test_vfsuid_root_in_currentns_invalid
> - test_vfsuid_root_in_currentns_nonzero
> - test_kuid_root_in_ns_init_ns_uid0
> - test_kuid_root_in_ns_init_ns_nonzero
> - test_kuid_root_in_ns_with_mapping
> - test_kuid_root_in_ns_with_different_mappings
>
> Updated MAINTAINER capabilities to include commoncap test
>
> Signed-off-by: Ryan Foster <foster.ryan.r@gmail.com>
Thanks! A few comments below. But the set of tests looks great.
> ---
> MAINTAINERS | 1 +
> security/Kconfig | 17 +++
> security/commoncap.c | 4 +
> security/commoncap_test.c | 290 ++++++++++++++++++++++++++++++++++++++
> 4 files changed, 312 insertions(+)
> create mode 100644 security/commoncap_test.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index c0030e126fc8..6f162c736dfb 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5682,6 +5682,7 @@ F: include/trace/events/capability.h
> F: include/uapi/linux/capability.h
> F: kernel/capability.c
> F: security/commoncap.c
> +F: security/commoncap_test.c
>
> CAPELLA MICROSYSTEMS LIGHT SENSOR DRIVER
> M: Kevin Tsai <ktsai@capellamicro.com>
> diff --git a/security/Kconfig b/security/Kconfig
> index 285f284dfcac..f47975284aab 100644
> --- a/security/Kconfig
> +++ b/security/Kconfig
> @@ -284,6 +284,23 @@ config LSM
>
> If unsure, leave this as the default.
>
> +config SECURITY_COMMONCAP_KUNIT_TEST
> + bool "Build KUnit tests for commoncap" if !KUNIT_ALL_TESTS
> + depends on KUNIT && USER_NS
> + default KUNIT_ALL_TESTS
I might be misunderstanding the syntax, but given that this is
only enabled (iiuc) if KUNIT_ALL_TESTS=false, then wouldn't it
be the same, and simpler, to say default false here?
I'm probably missing something.
> + help
> + This builds the commoncap KUnit tests.
> +
> + KUnit tests run during boot and output the results to the debug log
> + in TAP format (https://testanything.org/). Only useful for kernel devs
> + running KUnit test harness and are not for inclusion into a
> + production build.
> +
> + For more information on KUnit and unit tests in general please refer
> + to the KUnit documentation in Documentation/dev-tools/kunit/.
> +
> + If unsure, say N.
> +
> source "security/Kconfig.hardening"
>
> endmenu
> diff --git a/security/commoncap.c b/security/commoncap.c
> index 8a23dfab7fac..3399535808fe 100644
> --- a/security/commoncap.c
> +++ b/security/commoncap.c
> @@ -1521,3 +1521,7 @@ DEFINE_LSM(capability) = {
> };
>
> #endif /* CONFIG_SECURITY */
> +
> +#ifdef CONFIG_SECURITY_COMMONCAP_KUNIT_TEST
> +#include "commoncap_test.c"
> +#endif
> diff --git a/security/commoncap_test.c b/security/commoncap_test.c
> new file mode 100644
> index 000000000000..1088364a54e6
> --- /dev/null
> +++ b/security/commoncap_test.c
> @@ -0,0 +1,290 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * KUnit tests for commoncap.c security functions
> + *
> + * Tests for security-critical functions in the capability subsystem,
> + * particularly namespace-related capability checks.
> + */
> +
> +#include <kunit/test.h>
> +#include <linux/user_namespace.h>
> +#include <linux/uidgid.h>
> +#include <linux/cred.h>
> +#include <linux/mnt_idmapping.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/refcount.h>
> +
> +#ifdef CONFIG_SECURITY_COMMONCAP_KUNIT_TEST
> +
> +/* Functions are static in commoncap.c, but we can call them since we're
> + * included in the same compilation unit when tests are enabled.
> + */
> +
> +/**
> + * test_vfsuid_root_in_currentns_init_ns - Test vfsuid_root_in_currentns with init ns
> + *
> + * Verifies that UID 0 in the init namespace correctly owns the current
> + * namespace when running in init_user_ns.
> + *
> + * @test: KUnit test context
> + */
> +static void test_vfsuid_root_in_currentns_init_ns(struct kunit *test)
> +{
> + vfsuid_t vfsuid;
> + kuid_t kuid;
> +
> + /* Create UID 0 in init namespace */
> + kuid = KUIDT_INIT(0);
> + vfsuid = VFSUIDT_INIT(kuid);
> +
> + /* In init namespace, UID 0 should own current namespace */
> + KUNIT_EXPECT_TRUE(test, vfsuid_root_in_currentns(vfsuid));
> +}
> +
> +/**
> + * test_vfsuid_root_in_currentns_invalid - Test vfsuid_root_in_currentns with invalid vfsuid
> + *
> + * Verifies that an invalid vfsuid correctly returns false.
> + *
> + * @test: KUnit test context
> + */
> +static void test_vfsuid_root_in_currentns_invalid(struct kunit *test)
> +{
> + vfsuid_t invalid_vfsuid;
> +
> + /* Use the predefined invalid vfsuid */
> + invalid_vfsuid = INVALID_VFSUID;
> +
> + /* Invalid vfsuid should return false */
> + KUNIT_EXPECT_FALSE(test, vfsuid_root_in_currentns(invalid_vfsuid));
> +}
> +
> +/**
> + * test_vfsuid_root_in_currentns_nonzero - Test vfsuid_root_in_currentns with non-zero UID
> + *
> + * Verifies that a non-zero UID correctly returns false.
> + *
> + * @test: KUnit test context
> + */
> +static void test_vfsuid_root_in_currentns_nonzero(struct kunit *test)
> +{
> + vfsuid_t vfsuid;
> + kuid_t kuid;
> +
> + /* Create a non-zero UID */
> + kuid = KUIDT_INIT(1000);
> + vfsuid = VFSUIDT_INIT(kuid);
> +
> + /* Non-zero UID should return false */
> + KUNIT_EXPECT_FALSE(test, vfsuid_root_in_currentns(vfsuid));
> +}
> +
> +/**
> + * test_kuid_root_in_ns_init_ns_uid0 - Test kuid_root_in_ns with init namespace and UID 0
> + *
> + * Verifies that kuid_root_in_ns correctly identifies UID 0 in init namespace.
> + * This tests the core namespace traversal logic. In init namespace, UID 0
> + * maps to itself, so it should own the namespace.
> + *
> + * @test: KUnit test context
> + */
> +static void test_kuid_root_in_ns_init_ns_uid0(struct kunit *test)
> +{
> + kuid_t kuid;
> + struct user_namespace *init_ns;
> +
> + kuid = KUIDT_INIT(0);
> + init_ns = &init_user_ns;
> +
> + /* UID 0 should own init namespace */
> + KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(kuid, init_ns));
> +}
> +
> +/**
> + * test_kuid_root_in_ns_init_ns_nonzero - Test kuid_root_in_ns with init namespace and non-zero UID
> + *
> + * Verifies that kuid_root_in_ns correctly rejects non-zero UIDs in init namespace.
> + * Only UID 0 should own a namespace.
> + *
> + * @test: KUnit test context
> + */
> +static void test_kuid_root_in_ns_init_ns_nonzero(struct kunit *test)
> +{
> + kuid_t kuid;
> + struct user_namespace *init_ns;
> +
> + kuid = KUIDT_INIT(1000);
> + init_ns = &init_user_ns;
> +
> + /* Non-zero UID should not own namespace */
> + KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(kuid, init_ns));
> +}
> +
> +/**
> + * create_test_user_ns_with_mapping - Create a mock user namespace with UID mapping
> + *
> + * Creates a minimal user namespace structure for testing where uid 0 in the
> + * namespace maps to a specific kuid in the parent namespace.
> + *
> + * @test: KUnit test context
> + * @parent_ns: Parent namespace (typically init_user_ns)
> + * @mapped_kuid: The kuid that uid 0 in this namespace maps to in parent
> + *
> + * Returns: Pointer to allocated namespace, or NULL on failure
> + */
> +static struct user_namespace *create_test_user_ns_with_mapping(struct kunit *test,
> + struct user_namespace *parent_ns,
> + kuid_t mapped_kuid)
> +{
> + struct user_namespace *ns;
> + struct uid_gid_extent extent;
> +
> + /* Allocate a test namespace - use kzalloc to zero all fields */
> + ns = kunit_kzalloc(test, sizeof(*ns), GFP_KERNEL);
> + if (!ns)
> + return NULL;
> +
> + /* Initialize basic namespace structure fields */
> + ns->parent = parent_ns;
> + ns->level = parent_ns ? parent_ns->level + 1 : 0;
> + ns->owner = mapped_kuid;
> + ns->group = KGIDT_INIT(0);
> +
> + /* Initialize ns_common structure */
> + refcount_set(&ns->ns.__ns_ref, 1);
> + ns->ns.inum = 0; /* Mock inum */
> +
> + /* Set up uid mapping: uid 0 in this namespace maps to mapped_kuid in parent
> + * Format: first (uid in ns) : lower_first (kuid in parent) : count
> + * So: uid 0 in ns -> kuid mapped_kuid in parent
> + * This means from_kuid(ns, mapped_kuid) returns 0
> + */
> + extent.first = 0; /* uid 0 in this namespace */
> + extent.lower_first = __kuid_val(mapped_kuid); /* maps to this kuid in parent */
> + extent.count = 1;
> +
> + ns->uid_map.extent[0] = extent;
> + ns->uid_map.nr_extents = 1;
> +
> + /* Set up gid mapping: gid 0 maps to gid 0 in parent (simplified) */
> + extent.first = 0;
> + extent.lower_first = 0;
> + extent.count = 1;
> +
> + ns->gid_map.extent[0] = extent;
> + ns->gid_map.nr_extents = 1;
> +
> + return ns;
> +}
> +
> +/**
> + * test_kuid_root_in_ns_with_mapping - Test kuid_root_in_ns with namespace where uid 0
> + * maps to different kuid
> + *
> + * Creates a user namespace where uid 0 maps to kuid 1000 in the parent namespace.
> + * Verifies that kuid_root_in_ns correctly identifies kuid 1000 as owning the namespace.
> + *
> + * Note: kuid_root_in_ns walks up the namespace hierarchy, so it checks the current
> + * namespace first, then parent, then parent's parent, etc. So:
> + * - kuid 1000 owns test_ns because from_kuid(test_ns, 1000) == 0
> + * - kuid 0 also owns test_ns because from_kuid(init_user_ns, 0) == 0
> + * (checked in parent)
> + *
> + * This tests the actual functionality as requested: creating namespaces with
> + * different values for the namespace's uid 0.
> + *
> + * @test: KUnit test context
> + */
> +static void test_kuid_root_in_ns_with_mapping(struct kunit *test)
> +{
> + struct user_namespace *test_ns;
> + struct user_namespace *parent_ns;
> + kuid_t mapped_kuid, other_kuid;
> +
> + parent_ns = &init_user_ns;
> + mapped_kuid = KUIDT_INIT(1000);
> + other_kuid = KUIDT_INIT(2000);
> +
> + test_ns = create_test_user_ns_with_mapping(test, parent_ns, mapped_kuid);
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_ns);
> +
> + /* kuid 1000 should own test_ns because it maps to uid 0 in test_ns */
> + KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(mapped_kuid, test_ns));
> +
> + /* kuid 0 should also own test_ns (checked via parent init_user_ns) */
> + KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), test_ns));
> +
> + /* Other kuids should not own test_ns */
> + KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(other_kuid, test_ns));
> + KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(500), test_ns));
> +}
> +
> +/**
> + * test_kuid_root_in_ns_with_different_mappings - Test with multiple namespaces
> + *
> + * Creates multiple user namespaces with different UID mappings to verify
> + * that kuid_root_in_ns correctly handles different namespace hierarchies.
> + *
> + * Since kuid_root_in_ns walks up the hierarchy, kuids that map to 0 in init_user_ns
> + * will own all namespaces, while kuids that only map to 0 in specific namespaces
> + * will only own those namespaces and their children.
> + *
> + * @test: KUnit test context
> + */
> +static void test_kuid_root_in_ns_with_different_mappings(struct kunit *test)
> +{
> + struct user_namespace *ns1, *ns2, *ns3;
> +
> + /* Create ns1 where uid 0 maps to kuid 1000 */
> + ns1 = create_test_user_ns_with_mapping(test, &init_user_ns, KUIDT_INIT(1000));
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ns1);
> +
> + /* Create ns2 where uid 0 maps to kuid 2000 */
> + ns2 = create_test_user_ns_with_mapping(test, &init_user_ns, KUIDT_INIT(2000));
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ns2);
> +
> + /* Create ns3 as a child of ns1 where uid 0 maps to kuid 3000 */
> + ns3 = create_test_user_ns_with_mapping(test, ns1, KUIDT_INIT(3000));
This is not really a valid configuration, though. If ns3 is a child of ns1,
then any kuids mapped into ns3 must also have been mapped into ns1.
I think I'm ok with saying "it doesn't matter for this test", but it should
probably be documented here that we're ignoring that as irrelevant to the
test.
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ns3);
> +
> + /* Test ns1: kuid 1000 owns it, kuid 0 owns it (via parent), kuid 2000 does not */
> + KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(1000), ns1));
> + KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), ns1));
> + KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(2000), ns1));
> +
> + /* Test ns2: kuid 2000 owns it, kuid 0 owns it (via parent), kuid 1000 does not */
> + KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(2000), ns2));
> + KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), ns2));
> + KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(1000), ns2));
> +
> + /* Test ns3: kuid 3000 owns it, kuid 1000 owns it (via parent ns1),
> + * kuid 0 owns it (via init_user_ns), kuid 2000 does not
> + */
> + KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(3000), ns3));
> + KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(1000), ns3));
> + KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), ns3));
> + KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(2000), ns3));
> +}
> +
> +static struct kunit_case commoncap_test_cases[] = {
> + KUNIT_CASE(test_vfsuid_root_in_currentns_init_ns),
> + KUNIT_CASE(test_vfsuid_root_in_currentns_invalid),
> + KUNIT_CASE(test_vfsuid_root_in_currentns_nonzero),
> + KUNIT_CASE(test_kuid_root_in_ns_init_ns_uid0),
> + KUNIT_CASE(test_kuid_root_in_ns_init_ns_nonzero),
> + KUNIT_CASE(test_kuid_root_in_ns_with_mapping),
> + KUNIT_CASE(test_kuid_root_in_ns_with_different_mappings),
> + {}
> +};
> +
> +static struct kunit_suite commoncap_test_suite = {
> + .name = "commoncap",
> + .test_cases = commoncap_test_cases,
> +};
> +
> +kunit_test_suite(commoncap_test_suite);
> +
> +MODULE_LICENSE("GPL");
> +
> +#endif /* CONFIG_SECURITY_COMMONCAP_KUNIT_TEST */
> --
> 2.52.0
^ permalink raw reply
* Re: [PATCH v4] security: Add KUnit tests for kuid_root_in_ns and vfsuid_root_in_currentns
From: kernel test robot @ 2025-12-29 13:56 UTC (permalink / raw)
To: Ryan Foster, linux-security-module
Cc: oe-kbuild-all, linux-kernel, paul, serge, Ryan Foster
In-Reply-To: <20251228194838.32214-2-foster.ryan.r@gmail.com>
Hi Ryan,
kernel test robot noticed the following build errors:
[auto build test ERROR on pcmoore-selinux/next]
[also build test ERROR on linus/master v6.19-rc3 next-20251219]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Ryan-Foster/security-Add-KUnit-tests-for-kuid_root_in_ns-and-vfsuid_root_in_currentns/20251229-035056
base: https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux.git next
patch link: https://lore.kernel.org/r/20251228194838.32214-2-foster.ryan.r%40gmail.com
patch subject: [PATCH v4] security: Add KUnit tests for kuid_root_in_ns and vfsuid_root_in_currentns
config: i386-randconfig-011-20251229 (https://download.01.org/0day-ci/archive/20251229/202512292101.U530Lg4A-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251229/202512292101.U530Lg4A-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512292101.U530Lg4A-lkp@intel.com/
All errors (new ones prefixed by >>):
ld: security/commoncap.o: in function `kunit_kmalloc':
>> include/kunit/test.h:501:(.text+0xb59): undefined reference to `kunit_kmalloc_array'
ld: security/commoncap.o: in function `test_kuid_root_in_ns_init_ns_nonzero':
>> security/commoncap_test.c:121:(.text+0x109c): undefined reference to `kunit_unary_assert_format'
>> ld: security/commoncap_test.c:121:(.text+0x10aa): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap.o: in function `test_kuid_root_in_ns_init_ns_uid0':
security/commoncap_test.c:101:(.text+0x1101): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:101:(.text+0x110f): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap.o: in function `test_vfsuid_root_in_currentns_nonzero':
security/commoncap_test.c:80:(.text+0x14aa): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:80:(.text+0x14b8): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap.o: in function `test_vfsuid_root_in_currentns_init_ns':
security/commoncap_test.c:42:(.text+0x1544): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:42:(.text+0x1552): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap.o: in function `test_kuid_root_in_ns_with_mapping':
security/commoncap_test.c:219:(.text+0x166a): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:219:(.text+0x1678): undefined reference to `__kunit_do_failed_assertion'
>> ld: security/commoncap_test.c:220:(.text+0x16ca): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:220:(.text+0x16d8): undefined reference to `__kunit_do_failed_assertion'
>> ld: security/commoncap_test.c:210:(.text+0x16f8): undefined reference to `kunit_ptr_not_err_assert_format'
ld: security/commoncap_test.c:210:(.text+0x1706): undefined reference to `__kunit_do_failed_assertion'
>> ld: security/commoncap_test.c:210:(.text+0x170d): undefined reference to `__kunit_abort'
ld: security/commoncap_test.c:213:(.text+0x172c): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:213:(.text+0x173a): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:216:(.text+0x175c): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:216:(.text+0x176a): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap.o: in function `test_kuid_root_in_ns_with_different_mappings':
security/commoncap_test.c:254:(.text+0x18fa): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:254:(.text+0x1908): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:259:(.text+0x19da): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:259:(.text+0x19e8): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:267:(.text+0x1af2): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:267:(.text+0x1b00): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:241:(.text+0x1b20): undefined reference to `kunit_ptr_not_err_assert_format'
ld: security/commoncap_test.c:241:(.text+0x1b2e): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:241:(.text+0x1b35): undefined reference to `__kunit_abort'
ld: security/commoncap_test.c:245:(.text+0x1b50): undefined reference to `kunit_ptr_not_err_assert_format'
ld: security/commoncap_test.c:245:(.text+0x1b61): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:245:(.text+0x1b68): undefined reference to `__kunit_abort'
ld: security/commoncap_test.c:249:(.text+0x1b80): undefined reference to `kunit_ptr_not_err_assert_format'
ld: security/commoncap_test.c:249:(.text+0x1b8e): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:249:(.text+0x1b95): undefined reference to `__kunit_abort'
ld: security/commoncap_test.c:252:(.text+0x1bb4): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:252:(.text+0x1bc5): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:266:(.text+0x1bec): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:266:(.text+0x1bfa): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:265:(.text+0x1c1c): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:265:(.text+0x1c2a): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:264:(.text+0x1c4c): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:264:(.text+0x1c5a): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:253:(.text+0x1c7c): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:253:(.text+0x1c8d): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:258:(.text+0x1cb4): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:258:(.text+0x1cc2): undefined reference to `__kunit_do_failed_assertion'
ld: security/commoncap_test.c:257:(.text+0x1ce4): undefined reference to `kunit_unary_assert_format'
ld: security/commoncap_test.c:257:(.text+0x1cf2): undefined reference to `__kunit_do_failed_assertion'
vim +501 include/kunit/test.h
7122debb4367ee Daniel Latypov 2021-05-03 487
7122debb4367ee Daniel Latypov 2021-05-03 488 /**
7122debb4367ee Daniel Latypov 2021-05-03 489 * kunit_kmalloc() - Like kmalloc() except the allocation is *test managed*.
7122debb4367ee Daniel Latypov 2021-05-03 490 * @test: The test context object.
7122debb4367ee Daniel Latypov 2021-05-03 491 * @size: The size in bytes of the desired memory.
7122debb4367ee Daniel Latypov 2021-05-03 492 * @gfp: flags passed to underlying kmalloc().
7122debb4367ee Daniel Latypov 2021-05-03 493 *
7122debb4367ee Daniel Latypov 2021-05-03 494 * See kmalloc() and kunit_kmalloc_array() for more information.
57e3cded99e9c8 David Gow 2023-05-25 495 *
57e3cded99e9c8 David Gow 2023-05-25 496 * Note that some internal context data is also allocated with GFP_KERNEL,
57e3cded99e9c8 David Gow 2023-05-25 497 * regardless of the gfp passed in.
7122debb4367ee Daniel Latypov 2021-05-03 498 */
7122debb4367ee Daniel Latypov 2021-05-03 499 static inline void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
7122debb4367ee Daniel Latypov 2021-05-03 500 {
7122debb4367ee Daniel Latypov 2021-05-03 @501 return kunit_kmalloc_array(test, 1, size, gfp);
7122debb4367ee Daniel Latypov 2021-05-03 502 }
0a756853586ce1 Brendan Higgins 2019-09-23 503
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply
* [PATCH v5] security: Add KUnit tests for kuid_root_in_ns and vfsuid_root_in_currentns
From: Ryan Foster @ 2025-12-29 14:23 UTC (permalink / raw)
To: serge; +Cc: linux-security-module, linux-kernel, paul, Ryan Foster
In-Reply-To: <aVIAFEUjPe6DhrKc@mail.hallyn.com>
Hi Serge,
Thanks for the review. I have updated the patch to address the feedback
and build error from the intel CI.
Changes:
- Fixed build error, changed dependency to KUNIT=y so always built in
and not a module
- Fixed test invalid namespace configuration. Made test ns children of
init_user_ns, simpler config and expected logic.
With regards to the kconfig default, I copied this pattern over without
fully understanding the design, e.g. from lib/Kconfig. I believe
it is used to auto enable tests when running full test suite by default,
otherwise allowing for individual opt-in tests.
Thanks,
Ryan
Signed-off-by: Ryan Foster <foster.ryan.r@gmail.com>
---
MAINTAINERS | 1 +
security/Kconfig | 17 +++
security/commoncap.c | 4 +
security/commoncap_test.c | 288 ++++++++++++++++++++++++++++++++++++++
4 files changed, 310 insertions(+)
create mode 100644 security/commoncap_test.c
diff --git a/MAINTAINERS b/MAINTAINERS
index c0030e126fc8..6f162c736dfb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5682,6 +5682,7 @@ F: include/trace/events/capability.h
F: include/uapi/linux/capability.h
F: kernel/capability.c
F: security/commoncap.c
+F: security/commoncap_test.c
CAPELLA MICROSYSTEMS LIGHT SENSOR DRIVER
M: Kevin Tsai <ktsai@capellamicro.com>
diff --git a/security/Kconfig b/security/Kconfig
index 285f284dfcac..6a4393fce9a1 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -284,6 +284,23 @@ config LSM
If unsure, leave this as the default.
+config SECURITY_COMMONCAP_KUNIT_TEST
+ bool "Build KUnit tests for commoncap" if !KUNIT_ALL_TESTS
+ depends on KUNIT=y && USER_NS
+ default KUNIT_ALL_TESTS
+ help
+ This builds the commoncap KUnit tests.
+
+ KUnit tests run during boot and output the results to the debug log
+ in TAP format (https://testanything.org/). Only useful for kernel devs
+ running KUnit test harness and are not for inclusion into a
+ production build.
+
+ For more information on KUnit and unit tests in general please refer
+ to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+ If unsure, say N.
+
source "security/Kconfig.hardening"
endmenu
diff --git a/security/commoncap.c b/security/commoncap.c
index 8a23dfab7fac..3399535808fe 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -1521,3 +1521,7 @@ DEFINE_LSM(capability) = {
};
#endif /* CONFIG_SECURITY */
+
+#ifdef CONFIG_SECURITY_COMMONCAP_KUNIT_TEST
+#include "commoncap_test.c"
+#endif
diff --git a/security/commoncap_test.c b/security/commoncap_test.c
new file mode 100644
index 000000000000..e9b278be37f1
--- /dev/null
+++ b/security/commoncap_test.c
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * KUnit tests for commoncap.c security functions
+ *
+ * Tests for security-critical functions in the capability subsystem,
+ * particularly namespace-related capability checks.
+ */
+
+#include <kunit/test.h>
+#include <linux/user_namespace.h>
+#include <linux/uidgid.h>
+#include <linux/cred.h>
+#include <linux/mnt_idmapping.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/refcount.h>
+
+#ifdef CONFIG_SECURITY_COMMONCAP_KUNIT_TEST
+
+/* Functions are static in commoncap.c, but we can call them since we're
+ * included in the same compilation unit when tests are enabled.
+ */
+
+/**
+ * test_vfsuid_root_in_currentns_init_ns - Test vfsuid_root_in_currentns with init ns
+ *
+ * Verifies that UID 0 in the init namespace correctly owns the current
+ * namespace when running in init_user_ns.
+ *
+ * @test: KUnit test context
+ */
+static void test_vfsuid_root_in_currentns_init_ns(struct kunit *test)
+{
+ vfsuid_t vfsuid;
+ kuid_t kuid;
+
+ /* Create UID 0 in init namespace */
+ kuid = KUIDT_INIT(0);
+ vfsuid = VFSUIDT_INIT(kuid);
+
+ /* In init namespace, UID 0 should own current namespace */
+ KUNIT_EXPECT_TRUE(test, vfsuid_root_in_currentns(vfsuid));
+}
+
+/**
+ * test_vfsuid_root_in_currentns_invalid - Test vfsuid_root_in_currentns with invalid vfsuid
+ *
+ * Verifies that an invalid vfsuid correctly returns false.
+ *
+ * @test: KUnit test context
+ */
+static void test_vfsuid_root_in_currentns_invalid(struct kunit *test)
+{
+ vfsuid_t invalid_vfsuid;
+
+ /* Use the predefined invalid vfsuid */
+ invalid_vfsuid = INVALID_VFSUID;
+
+ /* Invalid vfsuid should return false */
+ KUNIT_EXPECT_FALSE(test, vfsuid_root_in_currentns(invalid_vfsuid));
+}
+
+/**
+ * test_vfsuid_root_in_currentns_nonzero - Test vfsuid_root_in_currentns with non-zero UID
+ *
+ * Verifies that a non-zero UID correctly returns false.
+ *
+ * @test: KUnit test context
+ */
+static void test_vfsuid_root_in_currentns_nonzero(struct kunit *test)
+{
+ vfsuid_t vfsuid;
+ kuid_t kuid;
+
+ /* Create a non-zero UID */
+ kuid = KUIDT_INIT(1000);
+ vfsuid = VFSUIDT_INIT(kuid);
+
+ /* Non-zero UID should return false */
+ KUNIT_EXPECT_FALSE(test, vfsuid_root_in_currentns(vfsuid));
+}
+
+/**
+ * test_kuid_root_in_ns_init_ns_uid0 - Test kuid_root_in_ns with init namespace and UID 0
+ *
+ * Verifies that kuid_root_in_ns correctly identifies UID 0 in init namespace.
+ * This tests the core namespace traversal logic. In init namespace, UID 0
+ * maps to itself, so it should own the namespace.
+ *
+ * @test: KUnit test context
+ */
+static void test_kuid_root_in_ns_init_ns_uid0(struct kunit *test)
+{
+ kuid_t kuid;
+ struct user_namespace *init_ns;
+
+ kuid = KUIDT_INIT(0);
+ init_ns = &init_user_ns;
+
+ /* UID 0 should own init namespace */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(kuid, init_ns));
+}
+
+/**
+ * test_kuid_root_in_ns_init_ns_nonzero - Test kuid_root_in_ns with init namespace and non-zero UID
+ *
+ * Verifies that kuid_root_in_ns correctly rejects non-zero UIDs in init namespace.
+ * Only UID 0 should own a namespace.
+ *
+ * @test: KUnit test context
+ */
+static void test_kuid_root_in_ns_init_ns_nonzero(struct kunit *test)
+{
+ kuid_t kuid;
+ struct user_namespace *init_ns;
+
+ kuid = KUIDT_INIT(1000);
+ init_ns = &init_user_ns;
+
+ /* Non-zero UID should not own namespace */
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(kuid, init_ns));
+}
+
+/**
+ * create_test_user_ns_with_mapping - Create a mock user namespace with UID mapping
+ *
+ * Creates a minimal user namespace structure for testing where uid 0 in the
+ * namespace maps to a specific kuid in the parent namespace.
+ *
+ * @test: KUnit test context
+ * @parent_ns: Parent namespace (typically init_user_ns)
+ * @mapped_kuid: The kuid that uid 0 in this namespace maps to in parent
+ *
+ * Returns: Pointer to allocated namespace, or NULL on failure
+ */
+static struct user_namespace *create_test_user_ns_with_mapping(struct kunit *test,
+ struct user_namespace *parent_ns,
+ kuid_t mapped_kuid)
+{
+ struct user_namespace *ns;
+ struct uid_gid_extent extent;
+
+ /* Allocate a test namespace - use kzalloc to zero all fields */
+ ns = kunit_kzalloc(test, sizeof(*ns), GFP_KERNEL);
+ if (!ns)
+ return NULL;
+
+ /* Initialize basic namespace structure fields */
+ ns->parent = parent_ns;
+ ns->level = parent_ns ? parent_ns->level + 1 : 0;
+ ns->owner = mapped_kuid;
+ ns->group = KGIDT_INIT(0);
+
+ /* Initialize ns_common structure */
+ refcount_set(&ns->ns.__ns_ref, 1);
+ ns->ns.inum = 0; /* Mock inum */
+
+ /* Set up uid mapping: uid 0 in this namespace maps to mapped_kuid in parent
+ * Format: first (uid in ns) : lower_first (kuid in parent) : count
+ * So: uid 0 in ns -> kuid mapped_kuid in parent
+ * This means from_kuid(ns, mapped_kuid) returns 0
+ */
+ extent.first = 0; /* uid 0 in this namespace */
+ extent.lower_first = __kuid_val(mapped_kuid); /* maps to this kuid in parent */
+ extent.count = 1;
+
+ ns->uid_map.extent[0] = extent;
+ ns->uid_map.nr_extents = 1;
+
+ /* Set up gid mapping: gid 0 maps to gid 0 in parent (simplified) */
+ extent.first = 0;
+ extent.lower_first = 0;
+ extent.count = 1;
+
+ ns->gid_map.extent[0] = extent;
+ ns->gid_map.nr_extents = 1;
+
+ return ns;
+}
+
+/**
+ * test_kuid_root_in_ns_with_mapping - Test kuid_root_in_ns with namespace where uid 0
+ * maps to different kuid
+ *
+ * Creates a user namespace where uid 0 maps to kuid 1000 in the parent namespace.
+ * Verifies that kuid_root_in_ns correctly identifies kuid 1000 as owning the namespace.
+ *
+ * Note: kuid_root_in_ns walks up the namespace hierarchy, so it checks the current
+ * namespace first, then parent, then parent's parent, etc. So:
+ * - kuid 1000 owns test_ns because from_kuid(test_ns, 1000) == 0
+ * - kuid 0 also owns test_ns because from_kuid(init_user_ns, 0) == 0
+ * (checked in parent)
+ *
+ * This tests the actual functionality as requested: creating namespaces with
+ * different values for the namespace's uid 0.
+ *
+ * @test: KUnit test context
+ */
+static void test_kuid_root_in_ns_with_mapping(struct kunit *test)
+{
+ struct user_namespace *test_ns;
+ struct user_namespace *parent_ns;
+ kuid_t mapped_kuid, other_kuid;
+
+ parent_ns = &init_user_ns;
+ mapped_kuid = KUIDT_INIT(1000);
+ other_kuid = KUIDT_INIT(2000);
+
+ test_ns = create_test_user_ns_with_mapping(test, parent_ns, mapped_kuid);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_ns);
+
+ /* kuid 1000 should own test_ns because it maps to uid 0 in test_ns */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(mapped_kuid, test_ns));
+
+ /* kuid 0 should also own test_ns (checked via parent init_user_ns) */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), test_ns));
+
+ /* Other kuids should not own test_ns */
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(other_kuid, test_ns));
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(500), test_ns));
+}
+
+/**
+ * test_kuid_root_in_ns_with_different_mappings - Test with multiple namespaces
+ *
+ * Creates multiple user namespaces with different UID mappings to verify
+ * that kuid_root_in_ns correctly distinguishes between namespaces.
+ *
+ * Each namespace maps uid 0 to a different kuid, and we verify that each
+ * kuid only owns its corresponding namespace (plus kuid 0 owns all via
+ * init_user_ns parent).
+ *
+ * @test: KUnit test context
+ */
+static void test_kuid_root_in_ns_with_different_mappings(struct kunit *test)
+{
+ struct user_namespace *ns1, *ns2, *ns3;
+
+ /* Create three independent namespaces, each mapping uid 0 to different kuids */
+ ns1 = create_test_user_ns_with_mapping(test, &init_user_ns, KUIDT_INIT(1000));
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ns1);
+
+ ns2 = create_test_user_ns_with_mapping(test, &init_user_ns, KUIDT_INIT(2000));
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ns2);
+
+ ns3 = create_test_user_ns_with_mapping(test, &init_user_ns, KUIDT_INIT(3000));
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ns3);
+
+ /* Test ns1: kuid 1000 owns it, kuid 0 owns it (via parent), others do not */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(1000), ns1));
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), ns1));
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(2000), ns1));
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(3000), ns1));
+
+ /* Test ns2: kuid 2000 owns it, kuid 0 owns it (via parent), others do not */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(2000), ns2));
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), ns2));
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(1000), ns2));
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(3000), ns2));
+
+ /* Test ns3: kuid 3000 owns it, kuid 0 owns it (via parent), others do not */
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(3000), ns3));
+ KUNIT_EXPECT_TRUE(test, kuid_root_in_ns(KUIDT_INIT(0), ns3));
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(1000), ns3));
+ KUNIT_EXPECT_FALSE(test, kuid_root_in_ns(KUIDT_INIT(2000), ns3));
+}
+
+static struct kunit_case commoncap_test_cases[] = {
+ KUNIT_CASE(test_vfsuid_root_in_currentns_init_ns),
+ KUNIT_CASE(test_vfsuid_root_in_currentns_invalid),
+ KUNIT_CASE(test_vfsuid_root_in_currentns_nonzero),
+ KUNIT_CASE(test_kuid_root_in_ns_init_ns_uid0),
+ KUNIT_CASE(test_kuid_root_in_ns_init_ns_nonzero),
+ KUNIT_CASE(test_kuid_root_in_ns_with_mapping),
+ KUNIT_CASE(test_kuid_root_in_ns_with_different_mappings),
+ {}
+};
+
+static struct kunit_suite commoncap_test_suite = {
+ .name = "commoncap",
+ .test_cases = commoncap_test_cases,
+};
+
+kunit_test_suite(commoncap_test_suite);
+
+MODULE_LICENSE("GPL");
+
+#endif /* CONFIG_SECURITY_COMMONCAP_KUNIT_TEST */
--
2.52.0
^ permalink raw reply related
* Re: [RFC 00/11] Reintroduce Hornet LSM
From: Ryan Foster @ 2025-12-29 17:12 UTC (permalink / raw)
To: bboscaccy
Cc: James.Bottomley, akpm, bpf, corbet, dhowells, foster.ryan.r,
gnoack, jmorris, linux-doc, linux-kernel, linux-security-module,
linux, mic, paul, serge
In-Reply-To: <87v7i4hpi4.fsf@microsoft.com>
Hi all,
I am considering how to reconcile the TOCTOU concern with the "don't touch BPF internals" feedback, I think a very small API might help:
Minimal API draft: BPF integrity measurement
Goal: kernel-generated measurement of the final relocated program + declared inputs, so attach/link can be enforced without poking internals.
1) New BPF cmd
- BPF_MEASURE_PROG (or BPF_PROG_MEASURE)
- Input: prog_fd
- Output: opaque measurement blob + metadata
struct bpf_prog_measure_opts {
__u32 size;
__u32 flags;
__u32 sig_len;
__u64 sig_ptr;
__u64 prog_id;
__u64 meas_id;
};
Semantics
- Kernel computes measurement over final relocated insns + inputs explicitly in the integrity contract (e.g., sealed maps).
- Measurement is kernel-owned and stable for a program state.
2) Per-prog integrity state
enum lsm_integrity_verdict {
LSM_INT_VERDICT_UNSIGNED,
LSM_INT_VERDICT_PARTIAL,
LSM_INT_VERDICT_OK,
LSM_INT_VERDICT_BADSIG,
};
struct bpf_prog_integrity {
__u64 meas_id;
enum lsm_integrity_verdict v;
};
- Attach/link allowed only if policy verdict passes.
- Any input mutation invalidates meas_id and resets verdict.
3) Input immutability
- Only sealed/frozen maps can be measured.
- Any write to a measured map invalidates the measurement.
4) LSM integration
- Hornet (or another integrity LSM) consumes the measurement blob, verifies signatures, stores verdict.
- SELinux/IPE/BPF LSMs can gate attach/link based on verdict.
Why this helps
- TOCTOU: verification tied to final relocated program + frozen inputs; mutations invalidate.
- No BPF internals: LSMs use a stable syscall API, not map internals.
- Minimal blast radius: one syscall + small per-prog state.
A thought for future iterations, happy to help refine if this seems useful.
Thanks,
Ryan
^ permalink raw reply
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