* [PATCH v3 0/3] lsm: introduce lsm_config_self_policy() and lsm_config_system_policy() syscalls
@ 2025-06-24 14:30 Maxime Bélair
2025-06-24 14:30 ` [PATCH v3 1/3] Wire up lsm_config_self_policy and lsm_config_system_policy syscalls Maxime Bélair
` (2 more replies)
0 siblings, 3 replies; 10+ messages in thread
From: Maxime Bélair @ 2025-06-24 14:30 UTC (permalink / raw)
To: linux-security-module
Cc: john.johansen, paul, jmorris, serge, mic, kees,
stephen.smalley.work, casey, takedakn, penguin-kernel, song,
rdunlap, linux-api, apparmor, linux-kernel, Maxime Bélair
This patchset introduces two new syscalls: lsm_config_self_policy(),
lsm_config_system_policy() and the associated Linux Security Module hooks
security_lsm_config_*_policy(), providing a unified interface for loading
and managing LSM policies. These syscalls complement the existing per‑LSM
pseudo‑filesystem mechanism and work even when those filesystems are not
mounted or available.
With these new syscalls, users and administrators may lock down access to
the pseudo‑filesystem yet still manage LSM policies. Two tightly-scoped
entry points then replace the many file operations exposed by those
filesystems, significantly reducing the attack surface. This is
particularly useful in containers or processes already confined by
Landlock, where these pseudo‑filesystems are typically unavailable.
Because they provide a logical and unified interface, these syscalls are
simpler to use than several heterogeneous pseudo‑filesystems and avoid
edge cases such as partially loaded policies. They also eliminates VFS
overhead, yielding performance gains notably when many policies are
loaded, for instance at boot time.
This initial implementation is intentionally minimal to limit the scope
of changes. Currently, only policy loading is supported, and only
AppArmor registers this LSM hook. However, any LSM can adopt this
interface, and future patches could extend this syscall to support more
operations, such as replacing, removing, or querying loaded policies.
Landlock already provides three Landlock‑specific syscalls (e.g.
landlock_add_rule()) to restrict ambient rights for sets of processes
without touching any pseudo-filesystem. lsm_config_*_policy() generalizes
that approach to the entire LSM layer, so any module can choose to
support either or both of these syscalls, and expose its policy
operations through a uniform interface and reap the advantages outlined
above.
This patchset is available at [1], a minimal user space example
showing how to use lsm_config_system_policy with AppArmor is at [2] and a
performance benchmark of both syscalls is available at [3].
[1] https://github.com/emixam16/linux/tree/lsm_syscall
[2] https://gitlab.com/emixam16/apparmor/tree/lsm_syscall
[3] https://gitlab.com/-/snippets/4864908
---
Changes in v3
- Fix typos
Changes in v2
- Split lsm_manage_policy() into two distinct syscalls:
lsm_config_self_policy() and lsm_config_system_policy()
- The LSM hook now calls only the appropriate LSM (and not all LSMs)
- Add a configuration variable to limit the buffer size of these
syscalls
- AppArmor now allows stacking policies through lsm_config_self_policy()
and loading policies in any namespace through
lsm_config_system_policy()
---
Maxime Bélair (3):
Wire up lsm_config_self_policy and lsm_config_system_policy syscalls
lsm: introduce security_lsm_config_*_policy hooks
AppArmor: add support for lsm_config_self_policy and
lsm_config_system_policy
arch/alpha/kernel/syscalls/syscall.tbl | 2 +
arch/arm/tools/syscall.tbl | 2 +
arch/m68k/kernel/syscalls/syscall.tbl | 2 +
arch/microblaze/kernel/syscalls/syscall.tbl | 2 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 2 +
arch/mips/kernel/syscalls/syscall_n64.tbl | 2 +
arch/mips/kernel/syscalls/syscall_o32.tbl | 2 +
arch/parisc/kernel/syscalls/syscall.tbl | 2 +
arch/powerpc/kernel/syscalls/syscall.tbl | 2 +
arch/s390/kernel/syscalls/syscall.tbl | 2 +
arch/sh/kernel/syscalls/syscall.tbl | 2 +
arch/sparc/kernel/syscalls/syscall.tbl | 2 +
arch/x86/entry/syscalls/syscall_32.tbl | 2 +
arch/x86/entry/syscalls/syscall_64.tbl | 2 +
arch/xtensa/kernel/syscalls/syscall.tbl | 2 +
include/linux/lsm_hook_defs.h | 4 ++
include/linux/security.h | 18 +++++
include/linux/syscalls.h | 5 ++
include/uapi/asm-generic/unistd.h | 6 +-
include/uapi/linux/lsm.h | 8 +++
kernel/sys_ni.c | 2 +
security/Kconfig | 22 ++++++
security/apparmor/apparmorfs.c | 31 ++++++++
security/apparmor/include/apparmorfs.h | 3 +
security/apparmor/lsm.c | 71 +++++++++++++++++++
security/lsm_syscalls.c | 25 +++++++
security/security.c | 69 ++++++++++++++++++
tools/include/uapi/asm-generic/unistd.h | 6 +-
.../arch/x86/entry/syscalls/syscall_64.tbl | 2 +
29 files changed, 300 insertions(+), 2 deletions(-)
base-commit: 9c32cda43eb78f78c73aee4aa344b777714e259b
--
2.48.1
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v3 1/3] Wire up lsm_config_self_policy and lsm_config_system_policy syscalls
2025-06-24 14:30 [PATCH v3 0/3] lsm: introduce lsm_config_self_policy() and lsm_config_system_policy() syscalls Maxime Bélair
@ 2025-06-24 14:30 ` Maxime Bélair
2025-06-27 6:31 ` kernel test robot
2025-06-24 14:30 ` [PATCH v3 2/3] lsm: introduce security_lsm_config_*_policy hooks Maxime Bélair
2025-06-24 14:30 ` [PATCH v3 3/3] AppArmor: add support for lsm_config_self_policy and lsm_config_system_policy Maxime Bélair
2 siblings, 1 reply; 10+ messages in thread
From: Maxime Bélair @ 2025-06-24 14:30 UTC (permalink / raw)
To: linux-security-module
Cc: john.johansen, paul, jmorris, serge, mic, kees,
stephen.smalley.work, casey, takedakn, penguin-kernel, song,
rdunlap, linux-api, apparmor, linux-kernel, Maxime Bélair
Add support for the new lsm_config_self_policy and
lsm_config_system_policy syscalls, providing a unified API for loading
and modifying LSM policies, for the current user and for the entire
system, respectively without requiring the LSM’s pseudo-filesystems.
Benefits:
- Works even if the LSM pseudo-filesystem isn’t mounted or available
(e.g. in containers)
- Offers a logical and unified interface rather than multiple
heterogeneous pseudo-filesystems
- Avoids the overhead of other kernel interfaces for better efficiency
Signed-off-by: Maxime Bélair <maxime.belair@canonical.com>
---
arch/alpha/kernel/syscalls/syscall.tbl | 2 ++
arch/arm/tools/syscall.tbl | 2 ++
arch/m68k/kernel/syscalls/syscall.tbl | 2 ++
arch/microblaze/kernel/syscalls/syscall.tbl | 2 ++
arch/mips/kernel/syscalls/syscall_n32.tbl | 2 ++
arch/mips/kernel/syscalls/syscall_n64.tbl | 2 ++
arch/mips/kernel/syscalls/syscall_o32.tbl | 2 ++
arch/parisc/kernel/syscalls/syscall.tbl | 2 ++
arch/powerpc/kernel/syscalls/syscall.tbl | 2 ++
arch/s390/kernel/syscalls/syscall.tbl | 2 ++
arch/sh/kernel/syscalls/syscall.tbl | 2 ++
arch/sparc/kernel/syscalls/syscall.tbl | 2 ++
arch/x86/entry/syscalls/syscall_32.tbl | 2 ++
arch/x86/entry/syscalls/syscall_64.tbl | 2 ++
arch/xtensa/kernel/syscalls/syscall.tbl | 2 ++
include/linux/syscalls.h | 5 +++++
include/uapi/asm-generic/unistd.h | 6 +++++-
kernel/sys_ni.c | 2 ++
security/lsm_syscalls.c | 12 ++++++++++++
tools/include/uapi/asm-generic/unistd.h | 6 +++++-
tools/perf/arch/x86/entry/syscalls/syscall_64.tbl | 2 ++
21 files changed, 61 insertions(+), 2 deletions(-)
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 2dd6340de6b4..4fc75352220d 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -507,3 +507,5 @@
575 common listxattrat sys_listxattrat
576 common removexattrat sys_removexattrat
577 common open_tree_attr sys_open_tree_attr
+578 common lsm_config_self_policy sys_lsm_config_self_policy
+579 common lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 27c1d5ebcd91..326483cb94a4 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -482,3 +482,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common lsm_config_self_policy sys_lsm_config_self_policy
+469 common lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 9fe47112c586..d37364df1cd7 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -467,3 +467,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common lsm_config_self_policy sys_lsm_config_self_policy
+469 common lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 7b6e97828e55..9d58ebfcf967 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -473,3 +473,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common lsm_config_self_policy sys_lsm_config_self_policy
+469 common lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index aa70e371bb54..8627b5f56280 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -406,3 +406,5 @@
465 n32 listxattrat sys_listxattrat
466 n32 removexattrat sys_removexattrat
467 n32 open_tree_attr sys_open_tree_attr
+468 n32 lsm_config_self_policy sys_lsm_config_self_policy
+469 n32 lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
index 1e8c44c7b614..813207b61f58 100644
--- a/arch/mips/kernel/syscalls/syscall_n64.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
@@ -382,3 +382,5 @@
465 n64 listxattrat sys_listxattrat
466 n64 removexattrat sys_removexattrat
467 n64 open_tree_attr sys_open_tree_attr
+468 n64 lsm_config_self_policy sys_lsm_config_self_policy
+469 n64 lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 114a5a1a6230..9cd0946b4370 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -455,3 +455,5 @@
465 o32 listxattrat sys_listxattrat
466 o32 removexattrat sys_removexattrat
467 o32 open_tree_attr sys_open_tree_attr
+468 o32 lsm_config_self_policy sys_lsm_config_self_policy
+469 o32 lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index 94df3cb957e9..9db01dd55793 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -466,3 +466,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common lsm_config_self_policy sys_lsm_config_self_policy
+469 common lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 9a084bdb8926..97714acb39ab 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -558,3 +558,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common lsm_config_self_policy sys_lsm_config_self_policy
+469 common lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index a4569b96ef06..d2b0f14fb516 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -470,3 +470,5 @@
465 common listxattrat sys_listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr sys_open_tree_attr
+468 common lsm_config_self_policy sys_lsm_config_self_policy sys_lsm_config_self_policy
+469 common lsm_config_system_policy sys_lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 52a7652fcff6..210d7118ce16 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -471,3 +471,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common lsm_config_self_policy sys_lsm_config_self_policy
+469 common lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index 83e45eb6c095..494417d80680 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -513,3 +513,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common lsm_config_self_policy sys_lsm_config_self_policy
+469 common lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index ac007ea00979..36c2c538e04f 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -473,3 +473,5 @@
465 i386 listxattrat sys_listxattrat
466 i386 removexattrat sys_removexattrat
467 i386 open_tree_attr sys_open_tree_attr
+468 i386 lsm_config_self_policy sys_lsm_config_self_policy
+469 i386 lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index cfb5ca41e30d..7eefbccfe531 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -391,6 +391,8 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common lsm_config_self_policy sys_lsm_config_self_policy
+469 common lsm_config_system_policy sys_lsm_config_system_policy
#
# Due to a historical design error, certain syscalls are numbered differently
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index f657a77314f8..90d86a54a952 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -438,3 +438,5 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common lsm_config_self_policy sys_lsm_config_self_policy
+469 common lsm_config_system_policy sys_lsm_config_system_policy
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index e5603cc91963..15b0f35c42fe 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -988,6 +988,11 @@ asmlinkage long sys_lsm_get_self_attr(unsigned int attr, struct lsm_ctx __user *
asmlinkage long sys_lsm_set_self_attr(unsigned int attr, struct lsm_ctx __user *ctx,
u32 size, u32 flags);
asmlinkage long sys_lsm_list_modules(u64 __user *ids, u32 __user *size, u32 flags);
+asmlinkage long sys_lsm_config_self_policy(u32 lsm_id, u32 op, void __user *buf,
+ u32 __user *size, u32 flags);
+asmlinkage long sys_lsm_config_system_policy(u32 lsm_id, u32 op, void __user *buf,
+ u32 __user *size, u32 flags);
+
/*
* Architecture-specific system calls
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 2892a45023af..34278cc6a476 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -851,9 +851,13 @@ __SYSCALL(__NR_listxattrat, sys_listxattrat)
__SYSCALL(__NR_removexattrat, sys_removexattrat)
#define __NR_open_tree_attr 467
__SYSCALL(__NR_open_tree_attr, sys_open_tree_attr)
+#define __NR_lsm_config_self_policy 468
+__SYSCALL(__NR_lsm_config_self_policy, lsm_config_self_policy)
+#define __NR_lsm_config_system_policy 469
+__SYSCALL(__NR_lsm_config_system_policy, lsm_config_system_policy)
#undef __NR_syscalls
-#define __NR_syscalls 468
+#define __NR_syscalls 470
/*
* 32 bit systems traditionally used different
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index c00a86931f8c..3ecebcd3fbe0 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -172,6 +172,8 @@ COND_SYSCALL_COMPAT(fadvise64_64);
COND_SYSCALL(lsm_get_self_attr);
COND_SYSCALL(lsm_set_self_attr);
COND_SYSCALL(lsm_list_modules);
+COND_SYSCALL(lsm_config_self_policy);
+COND_SYSCALL(lsm_config_system_policy);
/* CONFIG_MMU only */
COND_SYSCALL(swapon);
diff --git a/security/lsm_syscalls.c b/security/lsm_syscalls.c
index 8440948a690c..a3cb6dab8102 100644
--- a/security/lsm_syscalls.c
+++ b/security/lsm_syscalls.c
@@ -118,3 +118,15 @@ SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, u32 __user *, size,
return lsm_active_cnt;
}
+
+SYSCALL_DEFINE5(lsm_config_self_policy, u32, lsm_id, u32, op, void __user *,
+ buf, u32 __user *, size, u32, flags)
+{
+ return 0;
+}
+
+SYSCALL_DEFINE5(lsm_config_system_policy, u32, lsm_id, u32, op, void __user *,
+ buf, u32 __user *, size, u32, flags)
+{
+ return 0;
+}
diff --git a/tools/include/uapi/asm-generic/unistd.h b/tools/include/uapi/asm-generic/unistd.h
index 2892a45023af..34278cc6a476 100644
--- a/tools/include/uapi/asm-generic/unistd.h
+++ b/tools/include/uapi/asm-generic/unistd.h
@@ -851,9 +851,13 @@ __SYSCALL(__NR_listxattrat, sys_listxattrat)
__SYSCALL(__NR_removexattrat, sys_removexattrat)
#define __NR_open_tree_attr 467
__SYSCALL(__NR_open_tree_attr, sys_open_tree_attr)
+#define __NR_lsm_config_self_policy 468
+__SYSCALL(__NR_lsm_config_self_policy, lsm_config_self_policy)
+#define __NR_lsm_config_system_policy 469
+__SYSCALL(__NR_lsm_config_system_policy, lsm_config_system_policy)
#undef __NR_syscalls
-#define __NR_syscalls 468
+#define __NR_syscalls 470
/*
* 32 bit systems traditionally used different
diff --git a/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl b/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
index cfb5ca41e30d..7eefbccfe531 100644
--- a/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
@@ -391,6 +391,8 @@
465 common listxattrat sys_listxattrat
466 common removexattrat sys_removexattrat
467 common open_tree_attr sys_open_tree_attr
+468 common lsm_config_self_policy sys_lsm_config_self_policy
+469 common lsm_config_system_policy sys_lsm_config_system_policy
#
# Due to a historical design error, certain syscalls are numbered differently
--
2.48.1
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v3 2/3] lsm: introduce security_lsm_config_*_policy hooks
2025-06-24 14:30 [PATCH v3 0/3] lsm: introduce lsm_config_self_policy() and lsm_config_system_policy() syscalls Maxime Bélair
2025-06-24 14:30 ` [PATCH v3 1/3] Wire up lsm_config_self_policy and lsm_config_system_policy syscalls Maxime Bélair
@ 2025-06-24 14:30 ` Maxime Bélair
2025-06-25 0:42 ` kernel test robot
2025-06-25 1:08 ` Tetsuo Handa
2025-06-24 14:30 ` [PATCH v3 3/3] AppArmor: add support for lsm_config_self_policy and lsm_config_system_policy Maxime Bélair
2 siblings, 2 replies; 10+ messages in thread
From: Maxime Bélair @ 2025-06-24 14:30 UTC (permalink / raw)
To: linux-security-module
Cc: john.johansen, paul, jmorris, serge, mic, kees,
stephen.smalley.work, casey, takedakn, penguin-kernel, song,
rdunlap, linux-api, apparmor, linux-kernel, Maxime Bélair
Define two new LSM hooks: security_lsm_config_self_policy and
security_lsm_config_system_policy and wire them into the corresponding
lsm_config_*_policy() syscalls so that LSMs can register a unified
interface for policy management. This initial, minimal implementation
only supports the LSM_POLICY_LOAD operation to limit changes.
Signed-off-by: Maxime Bélair <maxime.belair@canonical.com>
---
include/linux/lsm_hook_defs.h | 4 ++
include/linux/security.h | 18 +++++++++
include/uapi/linux/lsm.h | 8 ++++
security/Kconfig | 22 +++++++++++
security/lsm_syscalls.c | 17 ++++++++-
security/security.c | 69 +++++++++++++++++++++++++++++++++++
6 files changed, 136 insertions(+), 2 deletions(-)
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index bf3bbac4e02a..fca490444643 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -464,3 +464,7 @@ LSM_HOOK(int, 0, bdev_alloc_security, struct block_device *bdev)
LSM_HOOK(void, LSM_RET_VOID, bdev_free_security, struct block_device *bdev)
LSM_HOOK(int, 0, bdev_setintegrity, struct block_device *bdev,
enum lsm_integrity_type type, const void *value, size_t size)
+LSM_HOOK(int, -EINVAL, lsm_config_self_policy, u32 lsm_id, u32 op,
+ void __user *buf, size_t size, u32 flags)
+LSM_HOOK(int, -EINVAL, lsm_config_system_policy, u32 lsm_id, u32 op,
+ void __user *buf, size_t size, u32 flags)
diff --git a/include/linux/security.h b/include/linux/security.h
index cc9b54d95d22..8ad988b87be4 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -581,6 +581,11 @@ void security_bdev_free(struct block_device *bdev);
int security_bdev_setintegrity(struct block_device *bdev,
enum lsm_integrity_type type, const void *value,
size_t size);
+int security_lsm_config_self_policy(u32 lsm_id, u32 op, void __user *buf,
+ size_t size, u32 flags);
+int security_lsm_config_system_policy(u32 lsm_id, u32 op, void __user *buf,
+ size_t size, u32 flags);
+
#else /* CONFIG_SECURITY */
/**
@@ -1603,6 +1608,19 @@ static inline int security_bdev_setintegrity(struct block_device *bdev,
return 0;
}
+static int security_lsm_config_self_policy(u32 lsm_id, u32 op, void __user *buf,
+ size_t size, u32 flags)
+{
+
+ return -EOPNOTSUPP;
+}
+
+static int security_lsm_config_system_policy(u32 lsm_id, u32 op, void __user *buf,
+ size_t size, u32 flags)
+{
+
+ return -EOPNOTSUPP;
+}
#endif /* CONFIG_SECURITY */
#if defined(CONFIG_SECURITY) && defined(CONFIG_WATCH_QUEUE)
diff --git a/include/uapi/linux/lsm.h b/include/uapi/linux/lsm.h
index 938593dfd5da..844279f819ce 100644
--- a/include/uapi/linux/lsm.h
+++ b/include/uapi/linux/lsm.h
@@ -90,4 +90,12 @@ struct lsm_ctx {
*/
#define LSM_FLAG_SINGLE 0x0001
+/*
+ * LSM_POLICY_XXX definitions identify the different operations
+ * configure lsm policies
+ */
+
+#define LSM_POLICY_UNDEF 0
+#define LSM_POLICY_LOAD 100
+
#endif /* _UAPI_LINUX_LSM_H */
diff --git a/security/Kconfig b/security/Kconfig
index 4816fc74f81e..b194f7f7a7c2 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -220,6 +220,28 @@ config STATIC_USERMODEHELPER_PATH
If you wish for all usermode helper programs to be disabled,
specify an empty string here (i.e. "").
+config LSM_CONFIG_SELF_POLICY_MAX_BUFFER_SIZE
+ int "Maximum buffer size for lsm_config_self_policy"
+ range 16384 1073741824
+ depends on SECURITY
+ default 4194304
+ help
+ The maximum size of the buffer argument of lsm_config_self_policy.
+
+ The default value of 4194304 (4MiB) is reasonable and should be large
+ enough to fit policies in for most cases.
+
+config LSM_CONFIG_SYSTEM_POLICY_MAX_BUFFER_SIZE
+ int "Maximum buffer size for lsm_config_system_policy"
+ range 16384 1073741824
+ depends on SECURITY
+ default 4194304
+ help
+ The maximum size of the buffer argument of lsm_config_system_policy.
+
+ The default value of 4194304 (4MiB) is reasonable and should be large
+ enough to fit policies in for most cases
+
source "security/selinux/Kconfig"
source "security/smack/Kconfig"
source "security/tomoyo/Kconfig"
diff --git a/security/lsm_syscalls.c b/security/lsm_syscalls.c
index a3cb6dab8102..dd016ba6976c 100644
--- a/security/lsm_syscalls.c
+++ b/security/lsm_syscalls.c
@@ -122,11 +122,24 @@ SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, u32 __user *, size,
SYSCALL_DEFINE5(lsm_config_self_policy, u32, lsm_id, u32, op, void __user *,
buf, u32 __user *, size, u32, flags)
{
- return 0;
+ size_t usize;
+
+ if (get_user(usize, size))
+ return -EFAULT;
+
+ return security_lsm_config_self_policy(lsm_id, op, buf, usize, flags);
}
SYSCALL_DEFINE5(lsm_config_system_policy, u32, lsm_id, u32, op, void __user *,
buf, u32 __user *, size, u32, flags)
{
- return 0;
+ size_t usize;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (get_user(usize, size))
+ return -EFAULT;
+
+ return security_lsm_config_system_policy(lsm_id, op, buf, usize, flags);
}
diff --git a/security/security.c b/security/security.c
index fb57e8fddd91..15bf3dab7892 100644
--- a/security/security.c
+++ b/security/security.c
@@ -5883,6 +5883,75 @@ int security_bdev_setintegrity(struct block_device *bdev,
}
EXPORT_SYMBOL(security_bdev_setintegrity);
+/**
+ * security_lsm_config_self_policy() - Configure caller's LSM policies
+ * @lsm_id: id of the LSM to target
+ * @op: Operation to perform (one of the LSM_POLICY_XXX values)
+ * @buf: userspace pointer to policy data
+ * @size: size of @buf
+ * @flags: lsm policy configuration flags
+ *
+ * Configure the policies of a LSM for the current domain/user. This notably
+ * allows to update them even when the lsmfs is unavailable or restricted.
+ * Currently, only LSM_POLICY_LOAD is supported.
+ *
+ * Return: Returns 0 on success, error on failure.
+ */
+int security_lsm_config_self_policy(u32 lsm_id, u32 op, void __user *buf,
+ size_t size, u32 flags)
+{
+ int rc = LSM_RET_DEFAULT(lsm_config_self_policy);
+ struct lsm_static_call *scall;
+
+ if (size > (CONFIG_LSM_CONFIG_SELF_POLICY_MAX_BUFFER_SIZE))
+ return -E2BIG;
+
+ lsm_for_each_hook(scall, lsm_config_self_policy) {
+ if ((scall->hl->lsmid->id) == lsm_id) {
+ rc = scall->hl->hook.lsm_config_self_policy(lsm_id, op, buf, size, flags);
+ break;
+ }
+ }
+
+ return rc;
+}
+EXPORT_SYMBOL(security_lsm_config_self_policy);
+
+/**
+ * security_lsm_config_system_policy() - Configure system LSM policies
+ * @lsm_id: id of the lsm to target
+ * @op: Operation to perform (one of the LSM_POLICY_XXX values)
+ * @buf: userspace pointer to policy data
+ * @size: size of @buf
+ * @flags: lsm policy configuration flags
+ *
+ * Configure the policies of a LSM for the whole system. This notably allows
+ * to update them even when the lsmfs is unavailable or restricted. Currently,
+ * only LSM_POLICY_LOAD is supported.
+ *
+ * Return: Returns 0 on success, error on failure.
+ */
+int security_lsm_config_system_policy(u32 lsm_id, u32 op, void __user *buf,
+ size_t size, u32 flags)
+{
+ int rc = LSM_RET_DEFAULT(lsm_config_system_policy);
+ struct lsm_static_call *scall;
+
+ if (size > (CONFIG_LSM_CONFIG_SYSTEM_POLICY_MAX_BUFFER_SIZE))
+ return -E2BIG;
+
+ lsm_for_each_hook(scall, lsm_config_system_policy) {
+ if ((scall->hl->lsmid->id) == lsm_id) {
+ rc = scall->hl->hook.lsm_config_system_policy(lsm_id, op, buf, size, flags);
+ break;
+ }
+ }
+
+ return rc;
+}
+EXPORT_SYMBOL(security_lsm_config_system_policy);
+
+
#ifdef CONFIG_PERF_EVENTS
/**
* security_perf_event_open() - Check if a perf event open is allowed
--
2.48.1
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v3 3/3] AppArmor: add support for lsm_config_self_policy and lsm_config_system_policy
2025-06-24 14:30 [PATCH v3 0/3] lsm: introduce lsm_config_self_policy() and lsm_config_system_policy() syscalls Maxime Bélair
2025-06-24 14:30 ` [PATCH v3 1/3] Wire up lsm_config_self_policy and lsm_config_system_policy syscalls Maxime Bélair
2025-06-24 14:30 ` [PATCH v3 2/3] lsm: introduce security_lsm_config_*_policy hooks Maxime Bélair
@ 2025-06-24 14:30 ` Maxime Bélair
2025-06-25 1:21 ` Tetsuo Handa
2 siblings, 1 reply; 10+ messages in thread
From: Maxime Bélair @ 2025-06-24 14:30 UTC (permalink / raw)
To: linux-security-module
Cc: john.johansen, paul, jmorris, serge, mic, kees,
stephen.smalley.work, casey, takedakn, penguin-kernel, song,
rdunlap, linux-api, apparmor, linux-kernel, Maxime Bélair
Enable users to manage AppArmor policies through the new hooks
lsm_config_self_policy and lsm_config_system_policy.
lsm_config_self_policy allows stacking existing policies in the kernel.
This ensures that it can only further restrict the caller and can never
be used to gain new privileges.
lsm_config_system_policy allows loading or replacing AppArmor policies in
any AppArmor namespace.
Signed-off-by: Maxime Bélair <maxime.belair@canonical.com>
---
security/apparmor/apparmorfs.c | 31 +++++++++++
security/apparmor/include/apparmorfs.h | 3 ++
security/apparmor/lsm.c | 71 ++++++++++++++++++++++++++
3 files changed, 105 insertions(+)
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 6039afae4bfc..6df43299b045 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -439,6 +439,37 @@ static ssize_t policy_update(u32 mask, const char __user *buf, size_t size,
return error;
}
+/**
+ * aa_profile_load_ns_name - load a profile into the current namespace identified by name
+ * @name: The name of the namesapce to load the policy in. "" for root_ns
+ * @name_size: size of @name. 0 For root ns
+ * @buf: buffer containing the user-provided policy
+ * @size: size of @buf
+ * @ppos: position pointer in the file
+ *
+ * Returns: 0 on success, negative value on error
+ */
+ssize_t aa_profile_load_ns_name(char *name, size_t name_size, const void __user *buf,
+ size_t size, loff_t *ppos)
+{
+ struct aa_ns *ns;
+
+ if (name_size == 0)
+ ns = aa_get_ns(root_ns);
+ else
+ ns = aa_lookupn_ns(root_ns, name, name_size);
+
+ if (!ns)
+ return -EINVAL;
+
+ int error = policy_update(AA_MAY_LOAD_POLICY | AA_MAY_REPLACE_POLICY,
+ buf, size, ppos, ns);
+
+ aa_put_ns(ns);
+
+ return error >= 0 ? 0 : error;
+}
+
/* .load file hook fn to load policy */
static ssize_t profile_load(struct file *f, const char __user *buf, size_t size,
loff_t *pos)
diff --git a/security/apparmor/include/apparmorfs.h b/security/apparmor/include/apparmorfs.h
index 1e94904f68d9..fd415afb7659 100644
--- a/security/apparmor/include/apparmorfs.h
+++ b/security/apparmor/include/apparmorfs.h
@@ -112,6 +112,9 @@ int __aafs_profile_mkdir(struct aa_profile *profile, struct dentry *parent);
void __aafs_ns_rmdir(struct aa_ns *ns);
int __aafs_ns_mkdir(struct aa_ns *ns, struct dentry *parent, const char *name,
struct dentry *dent);
+ssize_t aa_profile_load_ns_name(char *name, size_t name_len, const void __user *buf,
+ size_t size, loff_t *ppos);
+
struct aa_loaddata;
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 9b6c2f157f83..7ca2eb8c0981 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1275,6 +1275,73 @@ static int apparmor_socket_shutdown(struct socket *sock, int how)
return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock);
}
+/**
+ * apparmor_lsm_config_self_policy - Stack a profile
+ * @lsm_id: AppArmor ID (LSM_ID_APPARMOR). Unused here
+ * @op: operation to perform. Currently, only LSM_POLICY_LOAD is supported
+ * @buf: buffer containing the user-provided name of the profile to stack
+ * @size: size of @buf
+ * @flags: reserved for future use; must be zero
+ *
+ * Returns: 0 on success, negative value on error
+ */
+static int apparmor_lsm_config_self_policy(u32 lsm_id, u32 op, void __user *buf,
+ size_t size, u32 flags)
+{
+ char *name = kvmalloc(size, GFP_KERNEL);
+ long name_size;
+ int ret;
+
+ if (!name)
+ return -ENOMEM;
+
+ if (op != LSM_POLICY_LOAD || flags)
+ return -EOPNOTSUPP;
+
+ name_size = strncpy_from_user(name, buf, size);
+ if (name_size < 0)
+ return name_size;
+
+ ret = aa_change_profile(name, AA_CHANGE_STACK);
+
+ kvfree(name);
+
+ return ret;
+}
+
+/**
+ * apparmor_lsm_config_system_policy - Load or replace a system policy
+ * @lsm_id: AppArmor ID (LSM_ID_APPARMOR). Unused here
+ * @op: operation to perform. Currently, only LSM_POLICY_LOAD is supported
+ * @buf: user-supplied buffer in the form "<ns>\0<policy>"
+ * <ns> is the namespace to load the policy into (empty string for root)
+ * <policy> is the policy to load
+ * @size: size of @buf
+ * @flags: reserved for future uses; must be zero
+ *
+ * Returns: 0 on success, negative value on error
+ */
+static int apparmor_lsm_config_system_policy(u32 lsm_id, u32 op, void __user *buf,
+ size_t size, u32 flags)
+{
+ loff_t pos = 0; // Partial writing is not currently supported
+ char name[256];
+ long name_size;
+
+ if (op != LSM_POLICY_LOAD || flags)
+ return -EOPNOTSUPP;
+
+ name_size = strncpy_from_user(name, buf, 256);
+ if (name_size < 0)
+ return name_size;
+ else if (name_size == 256)
+ return -E2BIG;
+
+ return aa_profile_load_ns_name(name, name_size, buf + name_size + 1,
+ size - name_size - 1, &pos);
+}
+
+
#ifdef CONFIG_NETWORK_SECMARK
/**
* apparmor_socket_sock_rcv_skb - check perms before associating skb to sk
@@ -1483,6 +1550,10 @@ static struct security_hook_list apparmor_hooks[] __ro_after_init = {
LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt),
LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt),
LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown),
+
+ LSM_HOOK_INIT(lsm_config_self_policy, apparmor_lsm_config_self_policy),
+ LSM_HOOK_INIT(lsm_config_system_policy,
+ apparmor_lsm_config_system_policy),
#ifdef CONFIG_NETWORK_SECMARK
LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb),
#endif
--
2.48.1
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v3 2/3] lsm: introduce security_lsm_config_*_policy hooks
2025-06-24 14:30 ` [PATCH v3 2/3] lsm: introduce security_lsm_config_*_policy hooks Maxime Bélair
@ 2025-06-25 0:42 ` kernel test robot
2025-06-25 1:08 ` Tetsuo Handa
1 sibling, 0 replies; 10+ messages in thread
From: kernel test robot @ 2025-06-25 0:42 UTC (permalink / raw)
To: Maxime Bélair, linux-security-module
Cc: oe-kbuild-all, john.johansen, paul, jmorris, serge, mic, kees,
stephen.smalley.work, casey, takedakn, penguin-kernel, song,
rdunlap, linux-api, apparmor, linux-kernel, Maxime Bélair
Hi Maxime,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 9c32cda43eb78f78c73aee4aa344b777714e259b]
url: https://github.com/intel-lab-lkp/linux/commits/Maxime-B-lair/Wire-up-lsm_config_self_policy-and-lsm_config_system_policy-syscalls/20250624-225008
base: 9c32cda43eb78f78c73aee4aa344b777714e259b
patch link: https://lore.kernel.org/r/20250624143211.436045-3-maxime.belair%40canonical.com
patch subject: [PATCH v3 2/3] lsm: introduce security_lsm_config_*_policy hooks
config: openrisc-allnoconfig (https://download.01.org/0day-ci/archive/20250625/202506250843.UnXrlnza-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250625/202506250843.UnXrlnza-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/202506250843.UnXrlnza-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from include/linux/perf_event.h:62,
from include/linux/trace_events.h:10,
from include/trace/syscall.h:7,
from include/linux/syscalls.h:94,
from init/main.c:21:
>> include/linux/security.h:1618:12: warning: 'security_lsm_config_system_policy' defined but not used [-Wunused-function]
1618 | static int security_lsm_config_system_policy(u32 lsm_id, u32 op, void __user *buf,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/security.h:1611:12: warning: 'security_lsm_config_self_policy' defined but not used [-Wunused-function]
1611 | static int security_lsm_config_self_policy(u32 lsm_id, u32 op, void __user *buf,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +/security_lsm_config_system_policy +1618 include/linux/security.h
1617
> 1618 static int security_lsm_config_system_policy(u32 lsm_id, u32 op, void __user *buf,
1619 size_t size, u32 flags)
1620 {
1621
1622 return -EOPNOTSUPP;
1623 }
1624 #endif /* CONFIG_SECURITY */
1625
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v3 2/3] lsm: introduce security_lsm_config_*_policy hooks
2025-06-24 14:30 ` [PATCH v3 2/3] lsm: introduce security_lsm_config_*_policy hooks Maxime Bélair
2025-06-25 0:42 ` kernel test robot
@ 2025-06-25 1:08 ` Tetsuo Handa
2025-07-01 9:16 ` Maxime Bélair
1 sibling, 1 reply; 10+ messages in thread
From: Tetsuo Handa @ 2025-06-25 1:08 UTC (permalink / raw)
To: Maxime Bélair, linux-security-module
Cc: john.johansen, paul, jmorris, serge, mic, kees,
stephen.smalley.work, casey, takedakn, song, rdunlap, linux-api,
apparmor, linux-kernel
On 2025/06/24 23:30, Maxime Bélair wrote:
> +config LSM_CONFIG_SELF_POLICY_MAX_BUFFER_SIZE
> + int "Maximum buffer size for lsm_config_self_policy"
> + range 16384 1073741824
> + depends on SECURITY
> + default 4194304
> + help
> + The maximum size of the buffer argument of lsm_config_self_policy.
> +
> + The default value of 4194304 (4MiB) is reasonable and should be large
> + enough to fit policies in for most cases.
> +
Do we want to define LSM_CONFIG_{SELF,SYSTEM}_POLICY_MAX_BUFFER_SIZE as Kconfig?
If security_lsm_config_{self,system}_policy() are meant to be used by multiple
LSM modules, the upper limit each LSM module wants to impose would vary. Also,
1073741824 is larger than KMALLOC_MAX_SIZE; kmalloc()-based memory copying
functions will hit WARN_ON_ONCE_GFP() at __alloc_frozen_pages_noprof().
Since some of LSM modules might use vmalloc()-based memory copying functions from
security_lsm_config_{self,system}_policy(), the upper limit should be imposed by
individual LSM module which provides security_lsm_config_{self,system}_policy().
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v3 3/3] AppArmor: add support for lsm_config_self_policy and lsm_config_system_policy
2025-06-24 14:30 ` [PATCH v3 3/3] AppArmor: add support for lsm_config_self_policy and lsm_config_system_policy Maxime Bélair
@ 2025-06-25 1:21 ` Tetsuo Handa
2025-07-01 9:10 ` Maxime Bélair
0 siblings, 1 reply; 10+ messages in thread
From: Tetsuo Handa @ 2025-06-25 1:21 UTC (permalink / raw)
To: Maxime Bélair, linux-security-module
Cc: john.johansen, paul, jmorris, serge, mic, kees,
stephen.smalley.work, casey, takedakn, song, rdunlap, linux-api,
apparmor, linux-kernel
On 2025/06/24 23:30, Maxime Bélair wrote:
> +static int apparmor_lsm_config_self_policy(u32 lsm_id, u32 op, void __user *buf,
> + size_t size, u32 flags)
> +{
> + char *name = kvmalloc(size, GFP_KERNEL);
> + long name_size;
> + int ret;
> +
> + if (!name)
> + return -ENOMEM;
> +
> + if (op != LSM_POLICY_LOAD || flags)
Huge memory leak.
> + return -EOPNOTSUPP;
> +
> + name_size = strncpy_from_user(name, buf, size);
> + if (name_size < 0)
Here too. :-)
> + return name_size;
> +
> + ret = aa_change_profile(name, AA_CHANGE_STACK);
> +
> + kvfree(name);
> +
> + return ret;
> +}
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v3 1/3] Wire up lsm_config_self_policy and lsm_config_system_policy syscalls
2025-06-24 14:30 ` [PATCH v3 1/3] Wire up lsm_config_self_policy and lsm_config_system_policy syscalls Maxime Bélair
@ 2025-06-27 6:31 ` kernel test robot
0 siblings, 0 replies; 10+ messages in thread
From: kernel test robot @ 2025-06-27 6:31 UTC (permalink / raw)
To: Maxime Bélair, linux-security-module
Cc: oe-kbuild-all, john.johansen, paul, jmorris, serge, mic, kees,
stephen.smalley.work, casey, takedakn, penguin-kernel, song,
rdunlap, linux-api, apparmor, linux-kernel, Maxime Bélair
Hi Maxime,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 9c32cda43eb78f78c73aee4aa344b777714e259b]
url: https://github.com/intel-lab-lkp/linux/commits/Maxime-B-lair/Wire-up-lsm_config_self_policy-and-lsm_config_system_policy-syscalls/20250624-225008
base: 9c32cda43eb78f78c73aee4aa344b777714e259b
patch link: https://lore.kernel.org/r/20250624143211.436045-2-maxime.belair%40canonical.com
patch subject: [PATCH v3 1/3] Wire up lsm_config_self_policy and lsm_config_system_policy syscalls
config: riscv-randconfig-001-20250627 (https://download.01.org/0day-ci/archive/20250627/202506271432.Hsg0FzKQ-lkp@intel.com/config)
compiler: riscv32-linux-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250627/202506271432.Hsg0FzKQ-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/202506271432.Hsg0FzKQ-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from include/linux/compat.h:34,
from arch/riscv/include/asm/elf.h:12,
from include/linux/elf.h:6,
from include/linux/module.h:19,
from include/linux/bpf.h:20,
from include/linux/security.h:35,
from security/lsm_syscalls.c:13:
arch/riscv/include/asm/syscall_wrapper.h:35:14: warning: '__se_sys_lsm_set_self_attr' alias between functions of incompatible types 'long int(ulong, ulong, ulong, ulong, ulong, ulong, ulong)' {aka 'long int(long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int)'} and 'long int(long int, long int, long int, long int)' [-Wattribute-alias]
static long __se_##prefix##name(ulong, ulong, ulong, ulong, ulong, ulong, \
^~~~~
arch/riscv/include/asm/syscall_wrapper.h:82:2: note: in expansion of macro '__SYSCALL_SE_DEFINEx'
__SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__) \
^~~~~~~~~~~~~~~~~~~~
include/linux/syscalls.h:235:2: note: in expansion of macro '__SYSCALL_DEFINEx'
__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
^~~~~~~~~~~~~~~~~
include/linux/syscalls.h:227:36: note: in expansion of macro 'SYSCALL_DEFINEx'
#define SYSCALL_DEFINE4(name, ...) SYSCALL_DEFINEx(4, _##name, __VA_ARGS__)
^~~~~~~~~~~~~~~
security/lsm_syscalls.c:55:1: note: in expansion of macro 'SYSCALL_DEFINE4'
SYSCALL_DEFINE4(lsm_set_self_attr, unsigned int, attr, struct lsm_ctx __user *,
^~~~~~~~~~~~~~~
arch/riscv/include/asm/syscall_wrapper.h:41:14: note: aliased declaration here
static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
^~~~~~
arch/riscv/include/asm/syscall_wrapper.h:82:2: note: in expansion of macro '__SYSCALL_SE_DEFINEx'
__SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__) \
^~~~~~~~~~~~~~~~~~~~
include/linux/syscalls.h:235:2: note: in expansion of macro '__SYSCALL_DEFINEx'
__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
^~~~~~~~~~~~~~~~~
include/linux/syscalls.h:227:36: note: in expansion of macro 'SYSCALL_DEFINEx'
#define SYSCALL_DEFINE4(name, ...) SYSCALL_DEFINEx(4, _##name, __VA_ARGS__)
^~~~~~~~~~~~~~~
security/lsm_syscalls.c:55:1: note: in expansion of macro 'SYSCALL_DEFINE4'
SYSCALL_DEFINE4(lsm_set_self_attr, unsigned int, attr, struct lsm_ctx __user *,
^~~~~~~~~~~~~~~
>> arch/riscv/include/asm/syscall_wrapper.h:35:14: warning: '__se_sys_lsm_config_system_policy' alias between functions of incompatible types 'long int(ulong, ulong, ulong, ulong, ulong, ulong, ulong)' {aka 'long int(long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int)'} and 'long int(long int, long int, long int, long int, long int)' [-Wattribute-alias]
static long __se_##prefix##name(ulong, ulong, ulong, ulong, ulong, ulong, \
^~~~~
arch/riscv/include/asm/syscall_wrapper.h:82:2: note: in expansion of macro '__SYSCALL_SE_DEFINEx'
__SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__) \
^~~~~~~~~~~~~~~~~~~~
include/linux/syscalls.h:235:2: note: in expansion of macro '__SYSCALL_DEFINEx'
__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
^~~~~~~~~~~~~~~~~
include/linux/syscalls.h:228:36: note: in expansion of macro 'SYSCALL_DEFINEx'
#define SYSCALL_DEFINE5(name, ...) SYSCALL_DEFINEx(5, _##name, __VA_ARGS__)
^~~~~~~~~~~~~~~
security/lsm_syscalls.c:128:1: note: in expansion of macro 'SYSCALL_DEFINE5'
SYSCALL_DEFINE5(lsm_config_system_policy, u32, lsm_id, u32, op, void __user *,
^~~~~~~~~~~~~~~
arch/riscv/include/asm/syscall_wrapper.h:41:14: note: aliased declaration here
static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
^~~~~~
arch/riscv/include/asm/syscall_wrapper.h:82:2: note: in expansion of macro '__SYSCALL_SE_DEFINEx'
__SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__) \
^~~~~~~~~~~~~~~~~~~~
include/linux/syscalls.h:235:2: note: in expansion of macro '__SYSCALL_DEFINEx'
__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
^~~~~~~~~~~~~~~~~
include/linux/syscalls.h:228:36: note: in expansion of macro 'SYSCALL_DEFINEx'
#define SYSCALL_DEFINE5(name, ...) SYSCALL_DEFINEx(5, _##name, __VA_ARGS__)
^~~~~~~~~~~~~~~
security/lsm_syscalls.c:128:1: note: in expansion of macro 'SYSCALL_DEFINE5'
SYSCALL_DEFINE5(lsm_config_system_policy, u32, lsm_id, u32, op, void __user *,
^~~~~~~~~~~~~~~
>> arch/riscv/include/asm/syscall_wrapper.h:35:14: warning: '__se_sys_lsm_config_self_policy' alias between functions of incompatible types 'long int(ulong, ulong, ulong, ulong, ulong, ulong, ulong)' {aka 'long int(long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int)'} and 'long int(long int, long int, long int, long int, long int)' [-Wattribute-alias]
static long __se_##prefix##name(ulong, ulong, ulong, ulong, ulong, ulong, \
^~~~~
arch/riscv/include/asm/syscall_wrapper.h:82:2: note: in expansion of macro '__SYSCALL_SE_DEFINEx'
__SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__) \
^~~~~~~~~~~~~~~~~~~~
include/linux/syscalls.h:235:2: note: in expansion of macro '__SYSCALL_DEFINEx'
__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
^~~~~~~~~~~~~~~~~
include/linux/syscalls.h:228:36: note: in expansion of macro 'SYSCALL_DEFINEx'
#define SYSCALL_DEFINE5(name, ...) SYSCALL_DEFINEx(5, _##name, __VA_ARGS__)
^~~~~~~~~~~~~~~
security/lsm_syscalls.c:122:1: note: in expansion of macro 'SYSCALL_DEFINE5'
SYSCALL_DEFINE5(lsm_config_self_policy, u32, lsm_id, u32, op, void __user *,
^~~~~~~~~~~~~~~
arch/riscv/include/asm/syscall_wrapper.h:41:14: note: aliased declaration here
static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
^~~~~~
arch/riscv/include/asm/syscall_wrapper.h:82:2: note: in expansion of macro '__SYSCALL_SE_DEFINEx'
__SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__) \
^~~~~~~~~~~~~~~~~~~~
include/linux/syscalls.h:235:2: note: in expansion of macro '__SYSCALL_DEFINEx'
__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
^~~~~~~~~~~~~~~~~
include/linux/syscalls.h:228:36: note: in expansion of macro 'SYSCALL_DEFINEx'
#define SYSCALL_DEFINE5(name, ...) SYSCALL_DEFINEx(5, _##name, __VA_ARGS__)
^~~~~~~~~~~~~~~
security/lsm_syscalls.c:122:1: note: in expansion of macro 'SYSCALL_DEFINE5'
SYSCALL_DEFINE5(lsm_config_self_policy, u32, lsm_id, u32, op, void __user *,
^~~~~~~~~~~~~~~
arch/riscv/include/asm/syscall_wrapper.h:35:14: warning: '__se_sys_lsm_list_modules' alias between functions of incompatible types 'long int(ulong, ulong, ulong, ulong, ulong, ulong, ulong)' {aka 'long int(long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int)'} and 'long int(long int, long int, long int)' [-Wattribute-alias]
static long __se_##prefix##name(ulong, ulong, ulong, ulong, ulong, ulong, \
^~~~~
arch/riscv/include/asm/syscall_wrapper.h:82:2: note: in expansion of macro '__SYSCALL_SE_DEFINEx'
__SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__) \
^~~~~~~~~~~~~~~~~~~~
include/linux/syscalls.h:235:2: note: in expansion of macro '__SYSCALL_DEFINEx'
__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
^~~~~~~~~~~~~~~~~
include/linux/syscalls.h:226:36: note: in expansion of macro 'SYSCALL_DEFINEx'
#define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__)
^~~~~~~~~~~~~~~
security/lsm_syscalls.c:96:1: note: in expansion of macro 'SYSCALL_DEFINE3'
SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, u32 __user *, size,
^~~~~~~~~~~~~~~
arch/riscv/include/asm/syscall_wrapper.h:41:14: note: aliased declaration here
static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
^~~~~~
arch/riscv/include/asm/syscall_wrapper.h:82:2: note: in expansion of macro '__SYSCALL_SE_DEFINEx'
__SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__) \
^~~~~~~~~~~~~~~~~~~~
include/linux/syscalls.h:235:2: note: in expansion of macro '__SYSCALL_DEFINEx'
__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
^~~~~~~~~~~~~~~~~
include/linux/syscalls.h:226:36: note: in expansion of macro 'SYSCALL_DEFINEx'
#define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__)
^~~~~~~~~~~~~~~
security/lsm_syscalls.c:96:1: note: in expansion of macro 'SYSCALL_DEFINE3'
SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, u32 __user *, size,
^~~~~~~~~~~~~~~
arch/riscv/include/asm/syscall_wrapper.h:35:14: warning: '__se_sys_lsm_get_self_attr' alias between functions of incompatible types 'long int(ulong, ulong, ulong, ulong, ulong, ulong, ulong)' {aka 'long int(long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int)'} and 'long int(long int, long int, long int, long int)' [-Wattribute-alias]
static long __se_##prefix##name(ulong, ulong, ulong, ulong, ulong, ulong, \
^~~~~
arch/riscv/include/asm/syscall_wrapper.h:82:2: note: in expansion of macro '__SYSCALL_SE_DEFINEx'
__SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__) \
^~~~~~~~~~~~~~~~~~~~
include/linux/syscalls.h:235:2: note: in expansion of macro '__SYSCALL_DEFINEx'
__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
^~~~~~~~~~~~~~~~~
include/linux/syscalls.h:227:36: note: in expansion of macro 'SYSCALL_DEFINEx'
#define SYSCALL_DEFINE4(name, ...) SYSCALL_DEFINEx(4, _##name, __VA_ARGS__)
^~~~~~~~~~~~~~~
security/lsm_syscalls.c:77:1: note: in expansion of macro 'SYSCALL_DEFINE4'
SYSCALL_DEFINE4(lsm_get_self_attr, unsigned int, attr, struct lsm_ctx __user *,
^~~~~~~~~~~~~~~
arch/riscv/include/asm/syscall_wrapper.h:41:14: note: aliased declaration here
static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
^~~~~~
arch/riscv/include/asm/syscall_wrapper.h:82:2: note: in expansion of macro '__SYSCALL_SE_DEFINEx'
__SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__) \
^~~~~~~~~~~~~~~~~~~~
include/linux/syscalls.h:235:2: note: in expansion of macro '__SYSCALL_DEFINEx'
__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
^~~~~~~~~~~~~~~~~
include/linux/syscalls.h:227:36: note: in expansion of macro 'SYSCALL_DEFINEx'
#define SYSCALL_DEFINE4(name, ...) SYSCALL_DEFINEx(4, _##name, __VA_ARGS__)
^~~~~~~~~~~~~~~
security/lsm_syscalls.c:77:1: note: in expansion of macro 'SYSCALL_DEFINE4'
SYSCALL_DEFINE4(lsm_get_self_attr, unsigned int, attr, struct lsm_ctx __user *,
^~~~~~~~~~~~~~~
vim +35 arch/riscv/include/asm/syscall_wrapper.h
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 16
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 17 #define __SYSCALL_SE_DEFINEx(x, prefix, name, ...) \
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 18 static long __se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 19 static long __se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 20
08d0ce30e0e4fc Sami Tolvanen 2023-07-10 21 #define SC_RISCV_REGS_TO_ARGS(x, ...) \
08d0ce30e0e4fc Sami Tolvanen 2023-07-10 22 __MAP(x,__SC_ARGS \
08d0ce30e0e4fc Sami Tolvanen 2023-07-10 23 ,,regs->orig_a0,,regs->a1,,regs->a2 \
08d0ce30e0e4fc Sami Tolvanen 2023-07-10 24 ,,regs->a3,,regs->a4,,regs->a5,,regs->a6)
08d0ce30e0e4fc Sami Tolvanen 2023-07-10 25
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 26 #else
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 27 /*
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 28 * Use type aliasing to ensure registers a0-a6 are correctly passed to the syscall
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 29 * implementation when >word-size arguments are used.
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 30 */
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 31 #define __SYSCALL_SE_DEFINEx(x, prefix, name, ...) \
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 32 __diag_push(); \
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 33 __diag_ignore(GCC, 8, "-Wattribute-alias", \
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 34 "Type aliasing is used to sanitize syscall arguments"); \
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 @35 static long __se_##prefix##name(ulong, ulong, ulong, ulong, ulong, ulong, \
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 36 ulong) \
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 37 __attribute__((alias(__stringify(___se_##prefix##name)))); \
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 38 __diag_pop(); \
653650c468be21 Sami Tolvanen 2024-03-26 39 static long noinline ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
653650c468be21 Sami Tolvanen 2024-03-26 40 __used; \
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 41 static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
a9ad73295cc1e3 Sami Tolvanen 2024-03-11 42
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v3 3/3] AppArmor: add support for lsm_config_self_policy and lsm_config_system_policy
2025-06-25 1:21 ` Tetsuo Handa
@ 2025-07-01 9:10 ` Maxime Bélair
0 siblings, 0 replies; 10+ messages in thread
From: Maxime Bélair @ 2025-07-01 9:10 UTC (permalink / raw)
To: Tetsuo Handa, linux-security-module
Cc: john.johansen, paul, jmorris, serge, mic, kees,
stephen.smalley.work, casey, takedakn, song, rdunlap, linux-api,
apparmor, linux-kernel
On 6/25/25 03:21, Tetsuo Handa wrote:
> Huge memory leak.
> Here too. :-)
Nice catch, this is fixed in the next iteration.
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v3 2/3] lsm: introduce security_lsm_config_*_policy hooks
2025-06-25 1:08 ` Tetsuo Handa
@ 2025-07-01 9:16 ` Maxime Bélair
0 siblings, 0 replies; 10+ messages in thread
From: Maxime Bélair @ 2025-07-01 9:16 UTC (permalink / raw)
To: Tetsuo Handa, linux-security-module
Cc: john.johansen, paul, jmorris, serge, mic, kees,
stephen.smalley.work, casey, takedakn, song, rdunlap, linux-api,
apparmor, linux-kernel
On 6/25/25 03:08, Tetsuo Handa wrote:
> On 2025/06/24 23:30, Maxime Bélair wrote:
>> +config LSM_CONFIG_SELF_POLICY_MAX_BUFFER_SIZE
>> + int "Maximum buffer size for lsm_config_self_policy"
>> + range 16384 1073741824
>> + depends on SECURITY
>> + default 4194304
>> + help
>> + The maximum size of the buffer argument of lsm_config_self_policy.
>> +
>> + The default value of 4194304 (4MiB) is reasonable and should be large
>> + enough to fit policies in for most cases.
>> +
>
> Do we want to define LSM_CONFIG_{SELF,SYSTEM}_POLICY_MAX_BUFFER_SIZE as Kconfig?
>
> If security_lsm_config_{self,system}_policy() are meant to be used by multiple
> LSM modules, the upper limit each LSM module wants to impose would vary. Also,
> 1073741824 is larger than KMALLOC_MAX_SIZE; kmalloc()-based memory copying
> functions will hit WARN_ON_ONCE_GFP() at __alloc_frozen_pages_noprof().
>
> Since some of LSM modules might use vmalloc()-based memory copying functions from
> security_lsm_config_{self,system}_policy(), the upper limit should be imposed by
> individual LSM module which provides security_lsm_config_{self,system}_policy().
>
That makes sense. I removed this global Kconfig and the maximum buffer
size is now defined per module.
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2025-07-01 9:16 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-06-24 14:30 [PATCH v3 0/3] lsm: introduce lsm_config_self_policy() and lsm_config_system_policy() syscalls Maxime Bélair
2025-06-24 14:30 ` [PATCH v3 1/3] Wire up lsm_config_self_policy and lsm_config_system_policy syscalls Maxime Bélair
2025-06-27 6:31 ` kernel test robot
2025-06-24 14:30 ` [PATCH v3 2/3] lsm: introduce security_lsm_config_*_policy hooks Maxime Bélair
2025-06-25 0:42 ` kernel test robot
2025-06-25 1:08 ` Tetsuo Handa
2025-07-01 9:16 ` Maxime Bélair
2025-06-24 14:30 ` [PATCH v3 3/3] AppArmor: add support for lsm_config_self_policy and lsm_config_system_policy Maxime Bélair
2025-06-25 1:21 ` Tetsuo Handa
2025-07-01 9:10 ` Maxime Bélair
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