* [GIT PULL] selinux/selinux-pr-20260203
From: Paul Moore @ 2026-02-04 4:10 UTC (permalink / raw)
To: Linus Torvalds; +Cc: selinux, linux-security-module, linux-kernel
Linus,
This is a bit early, but due to some personal scheduling I'd rather send
this to you now, and you always mention you prefer to get pull requests
early (perhaps not this early?) so here is hoping this is a win-win.
Here are the highlights for the SELinux changes queued for the Linux v7.0
merge window:
- Add support for SELinux based access control of BPF tokens
We worked with the BPF devs to add the necessary LSM hooks when the BPF
token code was first introduced, but it took us a bit longer to add the
SELinux wiring and support. In order to preserve existing token-unaware
SELinux policies, the new code is gated by the new "bpf_token_perms"
policy capability.
Additional details regarding the new permissions, and behaviors can be
found in the associated commit.
- Remove a BUG() from the SELinux capability code
We now perform a similar check during compile time so we can safely
remove the BUG() call.
Paul
--
The following changes since commit 8f0b4cce4481fb22653697cced8d0d04027cb1e8:
Linux 6.19-rc1 (2025-12-14 16:05:07 +1200)
are available in the Git repository at:
https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux.git
tags/selinux-pr-20260203
for you to fetch changes up to ea64aa57d596c4cbe518ffd043c52ef64089708d:
selinux: drop the BUG() in cred_has_capability()
(2026-01-14 16:26:21 -0500)
----------------------------------------------------------------
selinux/stable-7.0 PR 20260203
----------------------------------------------------------------
Eric Suen (1):
selinux: add support for BPF token access control
Paul Moore (3):
selinux: move the selinux_blob_sizes struct
selinux: fix a capabilities parsing typo in
selinux_bpf_token_capable()
selinux: drop the BUG() in cred_has_capability()
security/selinux/hooks.c | 163 +++++++++++++++++----
security/selinux/include/classmap.h | 2
security/selinux/include/objsec.h | 3
security/selinux/include/policycap.h | 1
security/selinux/include/policycap_names.h | 1
security/selinux/include/security.h | 6
6 files changed, 151 insertions(+), 25 deletions(-)
--
paul-moore.com
^ permalink raw reply
* [PATCH v3 6/6] selftests/landlock: Add pathname socket variants for more tests
From: Tingmao Wang @ 2026-02-03 23:12 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, Justin Suess, linux-security-module
In-Reply-To: <cover.1770160146.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
relatively 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>
---
Changes in v3:
- Comment update, format
.../selftests/landlock/scoped_unix_test.c | 617 ++++++++++++------
1 file changed, 411 insertions(+), 206 deletions(-)
diff --git a/tools/testing/selftests/landlock/scoped_unix_test.c b/tools/testing/selftests/landlock/scoped_unix_test.c
index d117c85a2ca7..bc406c98f704 100644
--- a/tools/testing/selftests/landlock/scoped_unix_test.c
+++ b/tools/testing/selftests/landlock/scoped_unix_test.c
@@ -545,8 +545,12 @@ 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"
@@ -555,35 +559,79 @@ 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 &&
@@ -594,8 +642,7 @@ 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);
@@ -609,8 +656,7 @@ 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);
@@ -625,9 +671,7 @@ 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);
@@ -636,14 +680,12 @@ TEST_F(scoped_vs_unscoped, unix_scoping)
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_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);
@@ -661,15 +703,14 @@ TEST_F(scoped_vs_unscoped, unix_scoping)
/* Datagram sockets can "reconnect". */
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_err =
+ connect(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);
@@ -690,8 +731,7 @@ 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);
@@ -699,11 +739,11 @@ 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));
+ &child_stream_address->unix_addr,
+ 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_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));
@@ -717,19 +757,17 @@ 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));
@@ -743,57 +781,121 @@ 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, allow_dgram_child) {
+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, deny_dgram_server) {
+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, allow_stream_child) {
+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, deny_stream_server) {
+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, pathname_deny_dgram_server) {
+ /* clang-format on */
+ .child_socket = false,
+ .type = SOCK_DGRAM,
+ .abstract = false,
+};
+
+/* clang-format off */
+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, 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));
}
/*
@@ -807,6 +909,15 @@ 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));
@@ -821,8 +932,7 @@ 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;
@@ -832,8 +942,8 @@ 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);
@@ -848,8 +958,8 @@ 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 {
@@ -868,9 +978,8 @@ 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 {
@@ -879,10 +988,10 @@ 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));
@@ -897,52 +1006,90 @@ 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, pathname_socket_scoped_domain) {
+FIXTURE_VARIANT_ADD(various_address_sockets, scope_abstract) {
/* clang-format on */
- .domain = SCOPE_SANDBOX,
+ .scope_bits = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET,
};
/* clang-format off */
-FIXTURE_VARIANT_ADD(various_address_sockets, pathname_socket_other_domain) {
+FIXTURE_VARIANT_ADD(various_address_sockets, scope_pathname) {
/* clang-format on */
- .domain = OTHER_SANDBOX,
+ .scope_bits = LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET,
};
/* clang-format off */
-FIXTURE_VARIANT_ADD(various_address_sockets, pathname_socket_no_domain) {
+FIXTURE_VARIANT_ADD(various_address_sockets, scope_both) {
/* clang-format on */
- .domain = NO_SANDBOX,
+ .scope_bits = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
+ LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET,
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(various_address_sockets, scope_none) {
+ /* clang-format on */
+ .scope_bits = 0,
+};
+
+/* clang-format off */
+FIXTURE_VARIANT_ADD(various_address_sockets, no_domain) {
+ /* clang-format on */
+ .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;
@@ -951,25 +1098,10 @@ 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));
@@ -984,82 +1116,103 @@ 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 an 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);
-
- /* 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));
+ &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));
+ }
+
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);
@@ -1071,27 +1224,30 @@ 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]));
@@ -1101,24 +1257,31 @@ 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,
@@ -1134,30 +1297,76 @@ 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));
@@ -1177,9 +1386,9 @@ 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));
+ ASSERT_EQ(0, 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
@@ -1187,13 +1396,12 @@ 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
@@ -1201,8 +1409,8 @@ 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));
@@ -1219,10 +1427,11 @@ 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. */
@@ -1247,52 +1456,48 @@ 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));
+ ASSERT_EQ(-1, 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
* [PATCH v3 5/6] selftests/landlock: Repurpose scoped_abstract_unix_test.c for pathname sockets too
From: Tingmao Wang @ 2026-02-03 23:12 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, Justin Suess, linux-security-module
In-Reply-To: <cover.1770160146.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>
---
Changes in v3:
- Fix comment, style, formatting, and reflow the above message
- Update definition of log_match_remaining
...bstract_unix_test.c => scoped_unix_test.c} | 269 ++++++++++++++----
1 file changed, 217 insertions(+), 52 deletions(-)
rename tools/testing/selftests/landlock/{scoped_abstract_unix_test.c => scoped_unix_test.c} (80%)
diff --git a/tools/testing/selftests/landlock/scoped_abstract_unix_test.c b/tools/testing/selftests/landlock/scoped_unix_test.c
similarity index 80%
rename from tools/testing/selftests/landlock/scoped_abstract_unix_test.c
rename to tools/testing/selftests/landlock/scoped_unix_test.c
index 4a790e2d387d..d117c85a2ca7 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 +59,64 @@ 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 +127,7 @@ 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 +141,7 @@ 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 +151,8 @@ 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 +161,8 @@ 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 +175,16 @@ 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 +203,11 @@ 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 +215,14 @@ 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 +234,7 @@ 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 +247,7 @@ 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 +256,10 @@ 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 +276,7 @@ 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 +288,11 @@ 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 +313,79 @@ 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 +396,9 @@ 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 +416,22 @@ 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;
+ static const char abstract_log_regex[] = REGEX_LANDLOCK_PREFIX
+ " blockers=scope\\.abstract_unix_socket path=" ABSTRACT_SOCKET_PATH_PREFIX
+ "[0-9A-F]\\+$";
+ static const char pathname_log_template[] = REGEX_LANDLOCK_PREFIX
+ " blockers=scope\\.pathname_unix_socket path=\"%s\"$";
+ size_t log_match_remaining =
+ sizeof(abstract_log_regex) + PATH_MAX * 2 + 1;
+ char log_match[log_match_remaining];
+ char *log_match_cursor = log_match;
+
+ /* Make sure log_match_remaining calculation is correct */
+ static_assert(sizeof(pathname_log_template) <
+ sizeof(abstract_log_regex));
/* Makes sure there is no superfluous logged records. */
EXPECT_EQ(0, audit_count_records(self->audit_fd, &records));
@@ -330,8 +454,8 @@ 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 +469,9 @@ 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 +481,58 @@ 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, abstract_log_regex,
+ 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 *const 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\\.abstract_unix_socket path=" ABSTRACT_SOCKET_PATH_PREFIX
- "[0-9A-F]\\+$",
- NULL));
+ " blockers=scope\\.pathname_unix_socket path=\"",
+ log_match_remaining);
+ log_match_remaining =
+ sizeof(log_match) - (log_match_cursor - log_match);
+ ASSERT_NE(0, log_match_remaining);
+ log_match_cursor = regex_escape(absolute_path, log_match_cursor,
+ log_match_remaining);
+ free(absolute_path);
+ if (log_match_cursor < 0) {
+ TH_LOG("regex_escape() failed (buffer too small)");
+ return;
+ }
+ log_match_remaining =
+ sizeof(log_match) - (log_match_cursor - log_match);
+ ASSERT_NE(0, log_match_remaining);
+ log_match_cursor =
+ stpncpy(log_match_cursor, "\"$", 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 v3 4/6] selftests/landlock: Support pathname socket path in set_unix_address
From: Tingmao Wang @ 2026-02-03 23:12 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, Justin Suess, linux-security-module
In-Reply-To: <cover.1770160146.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 v3 3/6] samples/landlock: Support LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
From: Tingmao Wang @ 2026-02-03 23:12 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, Justin Suess, linux-security-module
In-Reply-To: <cover.1770160146.git.m@maowtm.org>
Add support for this new scope bit to the sandboxer via LL_SCOPED=u
Signed-off-by: Tingmao Wang <m@maowtm.org>
---
Changes in v3:
- Add message
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 v3 2/6] landlock: Implement LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
From: Tingmao Wang @ 2026-02-03 23:12 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, Justin Suess, linux-security-module
In-Reply-To: <cover.1770160146.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>
---
Changes in v3:
- missing dot in comment
- More accurate comment on check_socket_access
- Unix -> UNIX
Changes in v2:
- Factor out common code in hook_unix_stream_connect and
hook_unix_may_send into check_socket_access(), and inline
is_abstract_socket().
security/landlock/audit.c | 4 ++
security/landlock/audit.h | 1 +
security/landlock/task.c | 113 ++++++++++++++++++++++----------------
3 files changed, 71 insertions(+), 47 deletions(-)
diff --git a/security/landlock/audit.c b/security/landlock/audit.c
index 650bd7f5cb6b..97f0f503a836 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 104472060ef5..0e40fed17f21 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 833bc0cfe5c9..973de1efc08a 100644
--- a/security/landlock/task.c
+++ b/security/landlock/task.c
@@ -232,35 +232,85 @@ 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)
+/*
+ * 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 |
+ 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 cannot be used to reach a
+ * new peer.
+ */
+static int
+check_socket_access(struct sock *const other,
+ const struct landlock_cred_security *const subject,
+ const size_t handle_layer)
{
- struct unix_address *addr = unix_sk(sock)->addr;
+ const struct unix_address *addr = unix_sk(other)->addr;
+ access_mask_t scope;
+ enum landlock_request_type request_type;
+ /* Unnamed sockets are not restricted. */
if (!addr)
- return false;
+ return 0;
+ /*
+ * Abstract and pathname UNIX sockets have separate scope and audit
+ * request type.
+ */
if (addr->len >= offsetof(struct sockaddr_un, sun_path) + 1 &&
- addr->name->sun_path[0] == '\0')
- return true;
+ addr->name->sun_path[0] == '\0') {
+ 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;
+ }
- return false;
-}
+ if (!sock_is_scoped(other, subject->domain, scope))
+ return 0;
-static const struct access_masks unix_scope = {
- .scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET,
-};
+ landlock_log_denial(subject, &(struct landlock_request) {
+ .type = request_type,
+ .audit = {
+ .type = LSM_AUDIT_DATA_NET,
+ .u.net = &(struct lsm_network_audit) {
+ .sk = other,
+ },
+ },
+ .layer_plus_one = handle_layer + 1,
+ });
+ return -EPERM;
+}
static int hook_unix_stream_connect(struct sock *const sock,
struct sock *const other,
@@ -275,23 +325,7 @@ static int hook_unix_stream_connect(struct sock *const sock,
if (!subject)
return 0;
- if (!is_abstract_socket(other))
- return 0;
-
- if (!sock_is_scoped(other, subject->domain))
- return 0;
-
- landlock_log_denial(subject, &(struct landlock_request) {
- .type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET,
- .audit = {
- .type = LSM_AUDIT_DATA_NET,
- .u.net = &(struct lsm_network_audit) {
- .sk = other,
- },
- },
- .layer_plus_one = handle_layer + 1,
- });
- return -EPERM;
+ return check_socket_access(other, subject, handle_layer);
}
static int hook_unix_may_send(struct socket *const sock,
@@ -302,6 +336,7 @@ static int hook_unix_may_send(struct socket *const sock,
landlock_get_applicable_subject(current_cred(), unix_scope,
&handle_layer);
+ /* Quick return for non-landlocked tasks. */
if (!subject)
return 0;
@@ -312,23 +347,7 @@ 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))
- return 0;
-
- if (!sock_is_scoped(other->sk, subject->domain))
- return 0;
-
- landlock_log_denial(subject, &(struct landlock_request) {
- .type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET,
- .audit = {
- .type = LSM_AUDIT_DATA_NET,
- .u.net = &(struct lsm_network_audit) {
- .sk = other->sk,
- },
- },
- .layer_plus_one = handle_layer + 1,
- });
- return -EPERM;
+ return check_socket_access(other->sk, subject, handle_layer);
}
static const struct access_masks signal_scope = {
--
2.52.0
^ permalink raw reply related
* [PATCH v3 1/6] landlock: Add LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET scope bit to uAPI
From: Tingmao Wang @ 2026-02-03 23:12 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, Justin Suess, linux-security-module
In-Reply-To: <cover.1770160146.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 UNIX sockets.
Fix some minor cosmetic issue in landlock.h around the changed lines as
well.
Signed-off-by: Tingmao Wang <m@maowtm.org>
---
Changes in v3:
- Doc edit from review, update date
Changes in v2:
- Fix grammar
Note that in the code block in "Defining and enforcing a security policy"
the switch case currently jumps from 5 to 7. This should be fixed by
https://lore.kernel.org/all/20251216210248.4150777-1-samasth.norway.ananda@oracle.com/
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, 41 insertions(+), 12 deletions(-)
diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst
index 1d0c2c15c22e..b0d07051633b 100644
--- a/Documentation/userspace-api/landlock.rst
+++ b/Documentation/userspace-api/landlock.rst
@@ -8,7 +8,7 @@ Landlock: unprivileged access control
=====================================
:Author: Mickaël Salaün
-:Date: March 2025
+:Date: December 2025
The goal of Landlock is to enable restriction of ambient rights (e.g. global
filesystem or network access) for a set of processes. Because Landlock
@@ -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
@@ -127,6 +128,10 @@ 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 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.
@@ -328,10 +333,13 @@ 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.
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
@@ -604,6 +612,23 @@ 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 assume 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 75fd7f5e6cc3..7fa0e6c1a931 100644
--- a/include/uapi/linux/landlock.h
+++ b/include/uapi/linux/landlock.h
@@ -361,10 +361,14 @@ 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 v3 0/6] Landlock: Implement scope control for pathname Unix sockets
From: Tingmao Wang @ 2026-02-03 23:12 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Tingmao Wang, Günther Noack, Demi Marie Obenour, Alyssa Ross,
Jann Horn, Tahera Fahimi, Justin Suess, linux-security-module
This version contains some minor update based on feedback from Mickaël.
(Sending this anyway for completeness despite discussion in
https://lore.kernel.org/all/e6b6b069-384c-4c45-a56b-fa54b26bc72a@maowtm.org/ )
The rest is the same as the v2 cover letter:
Changes in v2:
Fix grammar in doc, rebased on mic/next, and extracted common code from
hook_unix_stream_connect and hook_unix_may_send into a separate
function.
The rest is the same as the v1 cover letter:
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 | 113 ++-
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} | 886 +++++++++++++-----
14 files changed, 787 insertions(+), 330 deletions(-)
rename tools/testing/selftests/landlock/{scoped_abstract_unix_test.c => scoped_unix_test.c} (50%)
base-commit: 24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7
prerequisite-patch-id: 5f3ab4d7ae2173abb98b510534b2eabc575944ed # https://lore.kernel.org/all/20251230103917.10549-3-gnoack3000@gmail.com/
prerequisite-patch-id: 0002366468db0afd2e68f4ee4f6cfb0d8e7ed315
--
2.52.0
^ permalink raw reply
* Re: [PATCH] xfrm: kill xfrm_dev_{state,policy}_flush_secctx_check()
From: Paul Moore @ 2026-02-03 22:40 UTC (permalink / raw)
To: Tetsuo Handa
Cc: SELinux, linux-security-module, Steffen Klassert, Herbert Xu,
David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
Simon Horman, Network Development
In-Reply-To: <f9b88268-03dc-4356-8b31-0bab73cc9b1e@I-love.SAKURA.ne.jp>
On Mon, Feb 2, 2026 at 10:48 PM Tetsuo Handa
<penguin-kernel@i-love.sakura.ne.jp> wrote:
> On 2026/02/02 13:07, Paul Moore wrote:
> > I'm asking you to verify that we have the LSM xfrm hooks in all of the
> > necessary locations to ensure that we are safely and comprehensively
> > gating all of the operations that result in removal of SPD and SAD
> > entries.
>
> That is impossible. We can't have the LSM xfrm hooks in all locations
> that result in removal of SPD and SAD entries.
It's a good thing that isn't what I said. I said "... LSM xfrm hooks
in all of the
necessary locations to ensure that we are safely and COMPREHENSIVELY
GATING all of the operations that result in removal of SPD and SAD
entries." I used the capitalization to emphasize the idea that the
goal is a comprehensive gating of the operations, not necessarily a
placement of LSM hooks in all of the functions. It can be a subtle
difference, but it is an important one as I think you can understand.
> It is your role (not my role) to verify that we have the LSM xfrm hooks in all
> of the necessary locations, for it is you who is wishing to ensure that we are
> safely and comprehensively gating all of the operations that result in removal
> of SPD and SAD entries.
All of us who contribute upstream have a responsibility to ensure the
proper operation and maintenance of the upstream Linux kernel, this is
especially true for individuals such as yourself who have accepted a
maintainer role.
You have identified what appear to be issues with the upstream kernel,
and have proposed changes to address that. While reviewing those
changes I asked you to verify that the LSM hooks associated with your
proposed change were still working as expected, since it was not clear
from the discussion, or the patch, that an investigation had taken
place. This is not an unusual request for such a proposed change, and
is something that I would expect a LSM maintainer to do without much
hesitation. If you are unwilling to investigate this, can you explain
why?
--
paul-moore.com
^ permalink raw reply
* Re: [PATCH net-next v2 0/4] net: uapi: Provide an UAPI definition of 'struct sockaddr'
From: Jakub Kicinski @ 2026-02-03 22:40 UTC (permalink / raw)
To: Thomas Weißschuh
Cc: Eric Dumazet, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn,
David S. Miller, Simon Horman, Shuah Khan, Matthieu Baerts,
Mat Martineau, Geliang Tang, Mickaël Salaün,
Günther Noack, Alexei Starovoitov, Daniel Borkmann,
Jesper Dangaard Brouer, John Fastabend, Stanislav Fomichev,
Andrii Nakryiko, Martin KaFai Lau, Eduard Zingerman, Song Liu,
Yonghong Song, KP Singh, Hao Luo, Jiri Olsa, netdev, linux-kernel,
linux-api, Arnd Bergmann, linux-kselftest, mptcp,
linux-security-module, bpf, libc-alpha, Carlos O'Donell,
Adhemerval Zanella, Rich Felker, klibc, Florian Weimer
In-Reply-To: <20260203122715-eeb304f9-4b42-4fc6-a527-658182a92ba5@linutronix.de>
On Tue, 3 Feb 2026 12:42:22 +0100 Thomas Weißschuh wrote:
> > FWIW the typelimits change broke compilation of ethtool, we'll see if
> > anyone "outside kernel community itself" complains.
>
> Can you point me to that breakage? I was unable to find it.
Not reported on the ML, and it's kinda annoying to repro because
the uAPI header sync script isn't committed :/ You have to check
this out
https://git.kernel.org/pub/scm/network/ethtool/ethtool.git/
and run a script like this to sync headers from the kernel (then build):
#!/bin/bash -e
sn="${0##*/}"
export ARCH="x86_64"
if [ ! -d "$LINUX_GIT" ]; then
echo "${sn}: LINUX_GIT not set" >&2
exit 1
fi
pushd "$LINUX_GIT"
if [ -n "$1" ]; then
git checkout "$1"
fi
desc=$(git describe --exact-match 2>/dev/null \
|| git show -s --abbrev=12 --pretty='commit %h')
kobj=$(mktemp -d)
make -j16 O="$kobj" allmodconfig
make -j16 O="$kobj" prepare
make -j16 O="$kobj" INSTALL_HDR_PATH="${kobj}/hdr" headers_install
popd
pushd uapi
find . -type f -name '*.h' -exec cp -v "${kobj}/hdr/include/{}" {} \;
popd
rm -rf "$kobj"
git add uapi
git commit -s -F - <<EOT
update UAPI header copies
Update to kernel ${desc}.
EOT
^ permalink raw reply
* Re: [PATCH v2 0/6] Landlock: Implement scope control for pathname Unix sockets
From: Tingmao Wang @ 2026-02-03 21:53 UTC (permalink / raw)
To: Günther Noack, Justin Suess, Mickaël Salaün
Cc: Günther Noack, Demi Marie Obenour, Alyssa Ross, Jann Horn,
Tahera Fahimi, linux-security-module
In-Reply-To: <aYI2OQhPMgdMAOiz@google.com>
On 2/3/26 17:54, Günther Noack wrote:
> On Tue, Feb 03, 2026 at 01:26:31AM +0000, Tingmao Wang wrote:
>> On 2/2/26 22:03, Justin Suess wrote:
>>> Regardless if you merge the patch series now in 7.0 or a later version, I think there is something to be said
>>> about having the filesystem and scoped unix access right merged in the same ABI version / merge window.
>>>
>>> As you pointed out earlier, the combination of the two flags is much flexible and useful to userspace
>>> consumers than one or the other, and if the features were merged separately, there would be an
>>> awkward middle ABI where user space consumers may have to make compromises or changes to
>>> sandbox between different versions or change application behavior.
>>> [...]
>>
>> Given that the scope bit and RESOLVE_UNIX access right are in some sense
>> part of the same system (they interact in an OR manner, after all), there
>> is some positive for having them introduced in the same version, but on
>> the other hand, with my above reasoning, I don't think these two
>> mechanisms (scope bit and RESOLVE_UNIX access) being in different ABI
>> versions would be too much of a problem. In either case, for applications
>> which require access to more "privileged" sockets, when running on a
>> kernel without the RESOLVE_UNIX access right support, no pathname socket
>> restrictions can be applied (i.e. it won't use the scope bit either, there
>> isn't much "compromise" it can make here). On the other hand, if
>> RESOLVE_UNIX is supported, then it knows that the scope bit is also
>> supported, and can just use it.
>
> Yes, but that does require additional subtle backwards compatibility
> logic in userspace libraries, to implement the "best effort" fallbacks.
>
> Assuming the scoped bit is added in v8 and the FS_RESOLVE_UNIX right in v9,
> if a user does this (in Go-landlock syntax):
>
> // restrict both scoped bit and FS RESOLVE_UNIX right, if possible
> landlock.V9.BestEffort().RestrictPaths(
> landlock.ResolveUnix("/tmp/socket"), // allow to connect to /tmp/socket
> )
>
> then if the system only supports ABI v8, it will have to clear both
> bits so that connections to /tmp/socket work,
> even though the scoped bit is technically supported on v8.
>
> **This requires additional logic in client libraries**,
> similar to our "refer" semantics (which users often get wrong):
>
> if (there is a rule that allows connections by path name)
> clear_the_scoped_bit_as_well();
> // even though the path name rule normally only affects a different bit
>
>
> In contrast, if both the scoped bit and FS_RESOLVE_UNIX were added in
> the same ABI version, then if a user does the above call, we are
> either equal-or-above that ABI version, in which case it works, or we
> are below that ABI version, in which case the two bits already get
> cleared from the landlock_ruleset_attr through the existing backwards
> compatibility mechanism.
>
> **In my mind, Justin is right that we should ideally introduce these
> together.** We have seen users implementing the "Refer" special case
> wrongly very often, it will likely happen here too, if we require
> extra logic in userspace libraries.
Ok, this makes sense to me. I will send the patch's next version as-is
anyway for completeness since it's basically done but I recognize that we
might change the plan based on this discussion.
>
>
> BTW, regarding the implementation: To have *OR* semantics for "within
> scope" and "allow-listed path", the implementation will be
> non-trivial, and I suspect we won't hit the merge window if we try to
> get them both in for 7.0. But in my mind, a simple UAPI is more
> important than trying to make it in time for the next merge window.
>
> (The implementation is difficult because the path-based and
> scope-based check currently happen in different LSM hooks, and none of
> the two hooks has enough information to make the decision alone. The
> second hook only gets called if the first returns 0. It'll require
> some further discussion to make it work together.)
Right. In that case, would it make sense to pass sk into the new
security_unix_find() hook, perhaps with the new argument named `struct
sock *other`? Then we can use this hook for the scope check as well by
using landlock_cred(other->sk_socket->file->f_cred)->domain etc.
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 227467236930..db9d279b3883 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1223,24 +1223,24 @@ static struct sock *unix_find_bsd(struct sockaddr_un *sunaddr, int addr_len,
err = -ECONNREFUSED;
inode = d_backing_inode(path.dentry);
if (!S_ISSOCK(inode->i_mode))
goto path_put;
+ err = -ECONNREFUSED;
+ sk = unix_find_socket_byinode(inode);
+ if (!sk)
+ goto path_put;
+
/*
* We call the hook because we know that the inode is a socket
* and we hold a valid reference to it via the path.
*/
- err = security_unix_find(&path, type, flags);
+ err = security_unix_find(&path, sk, flags);
if (err)
- goto path_put;
-
- err = -ECONNREFUSED;
- sk = unix_find_socket_byinode(inode);
- if (!sk)
- goto path_put;
+ goto sock_put;
err = -EPROTOTYPE;
if (sk->sk_type == type)
touch_atime(&path);
else
goto sock_put;
By doing this we won't even need to pass `type` separately anymore. The
only change would be that now one can determine if a socket is bound or
not even without being allowed RESOLVE_UNIX access. I'm not sure how much
of an issue this is, but we could also call the hook anyway with a NULL in
place of the new argument, if unix_find_socket_byinode() fails. Other
LSMs can then decide what to do in that case (either return -ECONNREFUSED
or -EPERM).
>
>
>> Furthermore, an application / Landlock config etc can always opt to not
>> use the scope bit at all, if it "knows" all the locations where the
>> application's sockets would be placed, and just use RESOLVE_UNIX access
>> right (or nothing if it is not supported).
>>
>> (The following is a bit of a side note, not terribly relevant if we're
>> deciding to go with the patch as is.)
>>
>>>> [...]
>>>> Another way to put it is that, if FS-based and scope-based controls
>>>> interacts in the above proposed way, both mechanisms feel like "poking
>>>> holes" in the other. But as Mickaël said, one can think of the two
>>>> mechanisms not as independent controls, but rather as two interfaces for
>>>> the same control. The socket access control is "enabled" if either the
>>>> LANDLOCK_ACCESS_FS_RESOLVE_UNIX access is handled, or the scope bit
>>>> proposed in this patch is enabled.
>>>>
>>>> With that said, I can think of some alternative ways that might make this
>>>> API look "better" (from a subjective point of view, feedback welcome),
>>>> however it does mean more delays, and specifically, these will depend on
>>>> LANDLOCK_ACCESS_FS_RESOLVE_UNIX:
>>>>
>>>> One possibility is to simply always allow a Landlock domain to connect to
>>>> its own sockets (in the case where LANDLOCK_ACCESS_FS_RESOLVE_UNIX is
>>>> handled, otherwise all sockets are allowed). This might be reasonable, as
>>>> one can only connect to a socket it creates if it has the permission to
>>>> create it in the first place, which is already controlled by
>>>> LANDLOCK_ACCESS_FS_MAKE_SOCK, so we don't really lose any policy
>>>> flexibility here - if for some reason the sandboxer don't want to allow
>>>> access to any (pathname) sockets, even the sandboxed app's own ones, it
>>>> can just not allow LANDLOCK_ACCESS_FS_MAKE_SOCK anywhere.
>>>
>>> LANDLOCK_ACCESS_FS_MAKE_SOCK is only required to bind/listen to a
>>> socket, not to connect. I guess you was thinking about
>>> LANDLOCK_ACCESS_FS_RESOLVE_UNIX in this case?
>>
>> In this "allow same-scope connect unconditionally" proposal, the
>> application would still be able to (bind to and) connect to its own
>> sockets, even if LANDLOCK_ACCESS_FS_RESOLVE_UNIX is handled and nothing is
>> allowed to have LANDLOCK_ACCESS_FS_RESOLVE_UNIX access. But a sandboxer
>> which for whatever reason doesn't want this "allow same scope" default can
>> still prevent the use of (pathname) sockets by restricting
>> LANDLOCK_ACCESS_FS_MAKE_SOCK, because if an app can't connect to any
>> sockets it doesn't own, and can't create any sockets itself either, then
>> it effectively can't connect to any sockets at all.
>>
>> (Although on second thought, I guess there could be a case where an app
>> first creates some socket files before doing landlock_restrict_self(),
>> then it might still be able to bind to these even without
>> LANDLOCK_ACCESS_FS_MAKE_SOCK?)
>
> FWIW, I also really liked Tingmao's first of the two listed
> possibilities in [1], where she proposed to introduce both rights
> together. In my understanding, the arguments we have discussed so far
> for that are:
>
> IN FAVOR:
>
> (pro1) Connecting to a UNIX socket in the same scope is always safe,
> and it makes it possible to use named UNIX sockets between the
> processes within a Landlock domains. (Mickaël convinced me in
> discussion at FOSDEM that this is true.)
>
> If someone absolutely does not want that, they can restrict
> LANDLOCK_ACCESS_FS_MAKE_SOCK and achieve the same effect (as
> Tingmao said above).
>
> (pro2) The implementation of this is simpler.
>
> (I attempted to understand how the "or" semantics would be
> implemented, and I found it non-trivial when you try to do it
> for all layers at once. (Kernighan's Law applies, IMHO))
I think the logic would basically be:
1. if any layers deny the access due to handled RESOLVE_UNIX but does not
have the scope bit set, then we will deny rightaway, without calling
domain_is_scoped().
2. Call domain_is_scoped() with a bitmask of "rules_covered" layers where
there are RESOLVE_UNIX rules covering the socket being accessed, and
essentially ignore those layers in the scope violation check.
I definitely agree that it is tricky, but making same-scope access be
allowed (i.e. the suggested idea above) would only get rid of step 1,
which I think is the "simpler" bit. The extra logic in step 2 is still
needed.
I definitely agree with pro1 tho.
>
> AGAINST:
>
> (con1) It would work differently than the other scoped access rights
> that we already have.
>
> A speculative feature that could potentially be built with the
> scoped access rights is that we could add a rule to permit IPC
> to other Landlock scopes, e.g. introducing a new rule type
>
> struct landlock_scope_attr {
> __u64 allowed_access; /* for "scoped" bits */
> /* some way to identify domains */
> }
>
> so that we could make IPC access to other Landlock domains
> configurable.
>
> If the scoped bit and the FS RESOLVE_UNIX bit were both
> conflated in RESOLVE_UNIX, it would not be possible to make
> UNIX connections configurable in such a way.
This exact API would no longer work, but if we give up the equivalence
between scope bits and the landlock_scope_attr struct, then we can do
something like:
struct landlock_scope_attr {
__u64 ptrace:1; /* Note that this is not a (user controllable) scope bit! */
__u64 abstract_unix_socket:1;
__u64 pathname_unix_socket:1;
/* ... */
__u64 allowed_signals;
/*
* some way to identify domains, maybe we could use the audit domain
* ID, with 0 denoting "allow access to non-Landlocked processes?
*/
}
>
> (con2) Consistent behaviour between scoped flags and their
> interactions with other access rights:
>
> The existing scoped access rights (signal, abstract sockets)
> could hypothetically be extended with a related access right of
> another type. For instance, there could be an access right type
>
> __u64 handled_signal_number;
>
> and then you could add a rule to permit the use of certain
> signal numbers. The interaction between the scoped flags and
> other access rights should work the same.
>
>
> Constructive Proposal for consideration: Why not both?
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I will think about the following a bit more but I'm afraid that I feel
like it might get slightly confusing. With this, the only reason for
having LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET is for API consistency when we
later enable allowing access to other domains (if I understood correctly),
in which case I personally feel like the suggestion on landlock_scope_attr
above, where we essentially accept that it is decoupled with the scope
bits in the ruleset, might be simpler...?
>
> Why not do both what Tingmao proposed in [1] **and** reserve the
> option to add the matching "scoped flag" later?
>
> * Introduce LANDLOCK_ACCESS_FS_RESOLVE_UNIX.
>
> If it is handled, UNIX connections are allowed either:
>
> (1) if the connection is to a service in the same scope, or
> (2) if the path was allow-listed with a "path beneath" rule.
>
> * Add LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET later, if needed.
>
>
> Let's go through the arguments again:
>
> We have observed that it is harmless to allow connections to services
> in the same scope (1), and that if users absolutely don't want that,
> they can actually prohibit it through LANDLOCK_ACCESS_FS_MAKE_SOCK
> (pro1).
>
> (con1): Can we still implement the feature idea where we poke a hole
> to get UNIX-connect() access to other Landlock domains?
>
> I think the answer is yes. The implementation strategy is:
>
> * Add the scoped bit LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
> * The scoped bit can now be used to allow-list connections to
> other Landlock domains.
>
> For users, just setting the scoped bit on its own does the same as
> handling LANDLOCK_ACCESS_FS_RESOLVE_UNIX. That way, the kernel-side
> implementation can also stay simple. The only reason why the scoped
> bit is needed is because it makes it possible to allow-list
> connections to other Landlock domains, but at the same time, it is
> safe if libraries set the scoped bit once it exists, as it does not
> have any bad runtime impact either.
>
> (con2): Consistency: Do all the scoped flags interact with their
> corresponding access rights in the same way?
>
> The other scope flags do not have corresponding access rights, so
> far.
>
> If we were to add corresponding access rights for the other scope
> flags, I would argue that we could apply a consistent logic there,
> because IPC access within the same scope is always safe:
>
> - A hypothetical access right type for "signal numbers" would only
> restrict signals that go beyond the current scope.
>
> - A hypothetical access right type for "abstract UNIX domain socket
> names" would only restrict connections to abstract UNIX domain
> servers that go beyond the current scope.
>
> I can not come up with a scenario where this doesn't work.
>
>
> In conclusion, I think the approach has significant upsides:
>
> * Simpler UAPI: Users only have one access bit to deal with, in the
> near future. Once we do add a scope flag for UNIX connections, it
> does not interact in a surprising way with the corresponding FS
> access right, because with either of these, scoped access is
> allowed.
>
> If users absolutely need to restrict scoped access, they can
> restrict LANDLOCK_ACCESS_FS_MAKE_SOCK. It is a slightly obscure
> API, but in line with the "make easy things easy, make hard things
> possible" API philosophy. And needing this should be the
> exception rather than the norm, after all.
>
> * Consistent behaviour between scoped flags and regular access
> rights, also for speculative access rights affecting the existing
> scoped flags for signals and abstract UNIX domain sockets.
>
> I know this was a slightly long mail, but I thought long and tried to
> be structured. Please let me know what you think.
>
> —Günther
>
>
> [1] https://lore.kernel.org/all/f07fe41a-96c5-4d3a-9966-35b30b3a71f1@maowtm.org/
^ permalink raw reply related
* Re: [PATCH] man/man7/kernel_lockdown.7: remove Secure Boot untruth
From: Heinrich Schuchardt @ 2026-02-03 20:47 UTC (permalink / raw)
To: Alejandro Colomar, Alyssa Ross
Cc: David Howells, Nicolas Bouchinet, Xiu Jianfeng,
linux-security-module, linux-man
In-Reply-To: <aYJZ31jO5ZE1Z6Xp@devuan>
Am 3. Februar 2026 21:27:44 MEZ schrieb Alejandro Colomar <alx@kernel.org>:
>Hi Alyssa,
>
>On 2026-02-03T20:53:33+0100, Alyssa Ross wrote:
>> On Tue, Feb 03, 2026 at 08:50:01PM +0100, Alyssa Ross wrote:
>> > This is true for Fedora, where this page was sourced from, but I don't
>> > believe it has ever been true for the mainline kernel, because Linus
>> > rejected it.
>> >
>> > Link: https://bbs.archlinux.org/viewtopic.php?pid=2088704#p2088704
>> > Link: https://lore.kernel.org/lkml/CA+55aFzYbpRAdma0PvqE+9ygySuKzNKByqOzzMufBoovXVnfPw@mail.gmail.com/
>> > Fixes: bb509e6fc ("kernel_lockdown.7: New page documenting the Kernel Lockdown feature")
>
>I've now CCed you in an email documenting the format we use for these.
>It should be:
>
>Fixes: bb509e6fcbae (2020-10-16; "kernel_lockdown.7: New page documenting the Kernel Lockdown feature")
>
>I'll amend that myself.
>
>> > Signed-off-by: Alyssa Ross <hi@alyssa.is>
>>
>> Just noticed there's a long-open bug for this as well, so additionally:
>>
>> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=213577
>
>Thanks! I'll keep the patch for a few days, in case anyone wants to
>comment.
>
>
>Have a lovely night!
>Alex
>
Can we move the information from the Notes section to replace the removed statement? What causes lockdown is central for users.
Best regards
Heinrich
^ permalink raw reply
* Re: [PATCH] man/man7/kernel_lockdown.7: remove Secure Boot untruth
From: Alejandro Colomar @ 2026-02-03 20:27 UTC (permalink / raw)
To: Alyssa Ross
Cc: Heinrich Schuchardt, David Howells, Nicolas Bouchinet,
Xiu Jianfeng, linux-security-module, linux-man
In-Reply-To: <aYJSDDwK1T9xxca1@mbp.qyliss.net>
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Hi Alyssa,
On 2026-02-03T20:53:33+0100, Alyssa Ross wrote:
> On Tue, Feb 03, 2026 at 08:50:01PM +0100, Alyssa Ross wrote:
> > This is true for Fedora, where this page was sourced from, but I don't
> > believe it has ever been true for the mainline kernel, because Linus
> > rejected it.
> >
> > Link: https://bbs.archlinux.org/viewtopic.php?pid=2088704#p2088704
> > Link: https://lore.kernel.org/lkml/CA+55aFzYbpRAdma0PvqE+9ygySuKzNKByqOzzMufBoovXVnfPw@mail.gmail.com/
> > Fixes: bb509e6fc ("kernel_lockdown.7: New page documenting the Kernel Lockdown feature")
I've now CCed you in an email documenting the format we use for these.
It should be:
Fixes: bb509e6fcbae (2020-10-16; "kernel_lockdown.7: New page documenting the Kernel Lockdown feature")
I'll amend that myself.
> > Signed-off-by: Alyssa Ross <hi@alyssa.is>
>
> Just noticed there's a long-open bug for this as well, so additionally:
>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=213577
Thanks! I'll keep the patch for a few days, in case anyone wants to
comment.
Have a lovely night!
Alex
--
<https://www.alejandro-colomar.es>
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^ permalink raw reply
* Re: [PATCH] man/man7/kernel_lockdown.7: remove Secure Boot untruth
From: Alyssa Ross @ 2026-02-03 19:53 UTC (permalink / raw)
To: Alejandro Colomar
Cc: Heinrich Schuchardt, David Howells, Nicolas Bouchinet,
Xiu Jianfeng, linux-security-module, linux-man
In-Reply-To: <20260203195001.20131-1-hi@alyssa.is>
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On Tue, Feb 03, 2026 at 08:50:01PM +0100, Alyssa Ross wrote:
> This is true for Fedora, where this page was sourced from, but I don't
> believe it has ever been true for the mainline kernel, because Linus
> rejected it.
>
> Link: https://bbs.archlinux.org/viewtopic.php?pid=2088704#p2088704
> Link: https://lore.kernel.org/lkml/CA+55aFzYbpRAdma0PvqE+9ygySuKzNKByqOzzMufBoovXVnfPw@mail.gmail.com/
> Fixes: bb509e6fc ("kernel_lockdown.7: New page documenting the Kernel Lockdown feature")
> Signed-off-by: Alyssa Ross <hi@alyssa.is>
Just noticed there's a long-open bug for this as well, so additionally:
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=213577
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^ permalink raw reply
* [PATCH] man/man7/kernel_lockdown.7: remove Secure Boot untruth
From: Alyssa Ross @ 2026-02-03 19:50 UTC (permalink / raw)
To: Alejandro Colomar
Cc: Heinrich Schuchardt, David Howells, Nicolas Bouchinet,
Xiu Jianfeng, linux-security-module, linux-man
This is true for Fedora, where this page was sourced from, but I don't
believe it has ever been true for the mainline kernel, because Linus
rejected it.
Link: https://bbs.archlinux.org/viewtopic.php?pid=2088704#p2088704
Link: https://lore.kernel.org/lkml/CA+55aFzYbpRAdma0PvqE+9ygySuKzNKByqOzzMufBoovXVnfPw@mail.gmail.com/
Fixes: bb509e6fc ("kernel_lockdown.7: New page documenting the Kernel Lockdown feature")
Signed-off-by: Alyssa Ross <hi@alyssa.is>
---
man/man7/kernel_lockdown.7 | 3 ---
1 file changed, 3 deletions(-)
diff --git a/man/man7/kernel_lockdown.7 b/man/man7/kernel_lockdown.7
index 5090484ea..5986c8f01 100644
--- a/man/man7/kernel_lockdown.7
+++ b/man/man7/kernel_lockdown.7
@@ -23,9 +23,6 @@ Lockdown: X: Y is restricted, see man kernel_lockdown.7
.in
.P
where X indicates the process name and Y indicates what is restricted.
-.P
-On an EFI-enabled x86 or arm64 machine, lockdown will be automatically enabled
-if the system boots in EFI Secure Boot mode.
.\"
.SS Coverage
When lockdown is in effect, a number of features are disabled or have their
--
2.52.0
^ permalink raw reply related
* Re: [PATCH v2 0/6] Landlock: Implement scope control for pathname Unix sockets
From: Günther Noack @ 2026-02-03 17:54 UTC (permalink / raw)
To: Tingmao Wang
Cc: Justin Suess, Mickaël Salaün, Günther Noack,
Demi Marie Obenour, Alyssa Ross, Jann Horn, Tahera Fahimi,
linux-security-module
In-Reply-To: <16129d76-b6d3-4959-b241-dc79a32dd0cd@maowtm.org>
On Tue, Feb 03, 2026 at 01:26:31AM +0000, Tingmao Wang wrote:
> On 2/2/26 22:03, Justin Suess wrote:
> > Regardless if you merge the patch series now in 7.0 or a later version, I think there is something to be said
> > about having the filesystem and scoped unix access right merged in the same ABI version / merge window.
> >
> > As you pointed out earlier, the combination of the two flags is much flexible and useful to userspace
> > consumers than one or the other, and if the features were merged separately, there would be an
> > awkward middle ABI where user space consumers may have to make compromises or changes to
> > sandbox between different versions or change application behavior.
> > [...]
>
> Given that the scope bit and RESOLVE_UNIX access right are in some sense
> part of the same system (they interact in an OR manner, after all), there
> is some positive for having them introduced in the same version, but on
> the other hand, with my above reasoning, I don't think these two
> mechanisms (scope bit and RESOLVE_UNIX access) being in different ABI
> versions would be too much of a problem. In either case, for applications
> which require access to more "privileged" sockets, when running on a
> kernel without the RESOLVE_UNIX access right support, no pathname socket
> restrictions can be applied (i.e. it won't use the scope bit either, there
> isn't much "compromise" it can make here). On the other hand, if
> RESOLVE_UNIX is supported, then it knows that the scope bit is also
> supported, and can just use it.
Yes, but that does require additional subtle backwards compatibility
logic in userspace libraries, to implement the "best effort" fallbacks.
Assuming the scoped bit is added in v8 and the FS_RESOLVE_UNIX right in v9,
if a user does this (in Go-landlock syntax):
// restrict both scoped bit and FS RESOLVE_UNIX right, if possible
landlock.V9.BestEffort().RestrictPaths(
landlock.ResolveUnix("/tmp/socket"), // allow to connect to /tmp/socket
)
then if the system only supports ABI v8, it will have to clear both
bits so that connections to /tmp/socket work,
even though the scoped bit is technically supported on v8.
**This requires additional logic in client libraries**,
similar to our "refer" semantics (which users often get wrong):
if (there is a rule that allows connections by path name)
clear_the_scoped_bit_as_well();
// even though the path name rule normally only affects a different bit
In contrast, if both the scoped bit and FS_RESOLVE_UNIX were added in
the same ABI version, then if a user does the above call, we are
either equal-or-above that ABI version, in which case it works, or we
are below that ABI version, in which case the two bits already get
cleared from the landlock_ruleset_attr through the existing backwards
compatibility mechanism.
**In my mind, Justin is right that we should ideally introduce these
together.** We have seen users implementing the "Refer" special case
wrongly very often, it will likely happen here too, if we require
extra logic in userspace libraries.
BTW, regarding the implementation: To have *OR* semantics for "within
scope" and "allow-listed path", the implementation will be
non-trivial, and I suspect we won't hit the merge window if we try to
get them both in for 7.0. But in my mind, a simple UAPI is more
important than trying to make it in time for the next merge window.
(The implementation is difficult because the path-based and
scope-based check currently happen in different LSM hooks, and none of
the two hooks has enough information to make the decision alone. The
second hook only gets called if the first returns 0. It'll require
some further discussion to make it work together.)
> Furthermore, an application / Landlock config etc can always opt to not
> use the scope bit at all, if it "knows" all the locations where the
> application's sockets would be placed, and just use RESOLVE_UNIX access
> right (or nothing if it is not supported).
>
> (The following is a bit of a side note, not terribly relevant if we're
> deciding to go with the patch as is.)
>
> >> [...]
> >> Another way to put it is that, if FS-based and scope-based controls
> >> interacts in the above proposed way, both mechanisms feel like "poking
> >> holes" in the other. But as Mickaël said, one can think of the two
> >> mechanisms not as independent controls, but rather as two interfaces for
> >> the same control. The socket access control is "enabled" if either the
> >> LANDLOCK_ACCESS_FS_RESOLVE_UNIX access is handled, or the scope bit
> >> proposed in this patch is enabled.
> >>
> >> With that said, I can think of some alternative ways that might make this
> >> API look "better" (from a subjective point of view, feedback welcome),
> >> however it does mean more delays, and specifically, these will depend on
> >> LANDLOCK_ACCESS_FS_RESOLVE_UNIX:
> >>
> >> One possibility is to simply always allow a Landlock domain to connect to
> >> its own sockets (in the case where LANDLOCK_ACCESS_FS_RESOLVE_UNIX is
> >> handled, otherwise all sockets are allowed). This might be reasonable, as
> >> one can only connect to a socket it creates if it has the permission to
> >> create it in the first place, which is already controlled by
> >> LANDLOCK_ACCESS_FS_MAKE_SOCK, so we don't really lose any policy
> >> flexibility here - if for some reason the sandboxer don't want to allow
> >> access to any (pathname) sockets, even the sandboxed app's own ones, it
> >> can just not allow LANDLOCK_ACCESS_FS_MAKE_SOCK anywhere.
> >
> > LANDLOCK_ACCESS_FS_MAKE_SOCK is only required to bind/listen to a
> > socket, not to connect. I guess you was thinking about
> > LANDLOCK_ACCESS_FS_RESOLVE_UNIX in this case?
>
> In this "allow same-scope connect unconditionally" proposal, the
> application would still be able to (bind to and) connect to its own
> sockets, even if LANDLOCK_ACCESS_FS_RESOLVE_UNIX is handled and nothing is
> allowed to have LANDLOCK_ACCESS_FS_RESOLVE_UNIX access. But a sandboxer
> which for whatever reason doesn't want this "allow same scope" default can
> still prevent the use of (pathname) sockets by restricting
> LANDLOCK_ACCESS_FS_MAKE_SOCK, because if an app can't connect to any
> sockets it doesn't own, and can't create any sockets itself either, then
> it effectively can't connect to any sockets at all.
>
> (Although on second thought, I guess there could be a case where an app
> first creates some socket files before doing landlock_restrict_self(),
> then it might still be able to bind to these even without
> LANDLOCK_ACCESS_FS_MAKE_SOCK?)
FWIW, I also really liked Tingmao's first of the two listed
possibilities in [1], where she proposed to introduce both rights
together. In my understanding, the arguments we have discussed so far
for that are:
IN FAVOR:
(pro1) Connecting to a UNIX socket in the same scope is always safe,
and it makes it possible to use named UNIX sockets between the
processes within a Landlock domains. (Mickaël convinced me in
discussion at FOSDEM that this is true.)
If someone absolutely does not want that, they can restrict
LANDLOCK_ACCESS_FS_MAKE_SOCK and achieve the same effect (as
Tingmao said above).
(pro2) The implementation of this is simpler.
(I attempted to understand how the "or" semantics would be
implemented, and I found it non-trivial when you try to do it
for all layers at once. (Kernighan's Law applies, IMHO))
AGAINST:
(con1) It would work differently than the other scoped access rights
that we already have.
A speculative feature that could potentially be built with the
scoped access rights is that we could add a rule to permit IPC
to other Landlock scopes, e.g. introducing a new rule type
struct landlock_scope_attr {
__u64 allowed_access; /* for "scoped" bits */
/* some way to identify domains */
}
so that we could make IPC access to other Landlock domains
configurable.
If the scoped bit and the FS RESOLVE_UNIX bit were both
conflated in RESOLVE_UNIX, it would not be possible to make
UNIX connections configurable in such a way.
(con2) Consistent behaviour between scoped flags and their
interactions with other access rights:
The existing scoped access rights (signal, abstract sockets)
could hypothetically be extended with a related access right of
another type. For instance, there could be an access right type
__u64 handled_signal_number;
and then you could add a rule to permit the use of certain
signal numbers. The interaction between the scoped flags and
other access rights should work the same.
Constructive Proposal for consideration: Why not both?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Why not do both what Tingmao proposed in [1] **and** reserve the
option to add the matching "scoped flag" later?
* Introduce LANDLOCK_ACCESS_FS_RESOLVE_UNIX.
If it is handled, UNIX connections are allowed either:
(1) if the connection is to a service in the same scope, or
(2) if the path was allow-listed with a "path beneath" rule.
* Add LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET later, if needed.
Let's go through the arguments again:
We have observed that it is harmless to allow connections to services
in the same scope (1), and that if users absolutely don't want that,
they can actually prohibit it through LANDLOCK_ACCESS_FS_MAKE_SOCK
(pro1).
(con1): Can we still implement the feature idea where we poke a hole
to get UNIX-connect() access to other Landlock domains?
I think the answer is yes. The implementation strategy is:
* Add the scoped bit LANDLOCK_SCOPE_PATHNAME_UNIX_SOCKET
* The scoped bit can now be used to allow-list connections to
other Landlock domains.
For users, just setting the scoped bit on its own does the same as
handling LANDLOCK_ACCESS_FS_RESOLVE_UNIX. That way, the kernel-side
implementation can also stay simple. The only reason why the scoped
bit is needed is because it makes it possible to allow-list
connections to other Landlock domains, but at the same time, it is
safe if libraries set the scoped bit once it exists, as it does not
have any bad runtime impact either.
(con2): Consistency: Do all the scoped flags interact with their
corresponding access rights in the same way?
The other scope flags do not have corresponding access rights, so
far.
If we were to add corresponding access rights for the other scope
flags, I would argue that we could apply a consistent logic there,
because IPC access within the same scope is always safe:
- A hypothetical access right type for "signal numbers" would only
restrict signals that go beyond the current scope.
- A hypothetical access right type for "abstract UNIX domain socket
names" would only restrict connections to abstract UNIX domain
servers that go beyond the current scope.
I can not come up with a scenario where this doesn't work.
In conclusion, I think the approach has significant upsides:
* Simpler UAPI: Users only have one access bit to deal with, in the
near future. Once we do add a scope flag for UNIX connections, it
does not interact in a surprising way with the corresponding FS
access right, because with either of these, scoped access is
allowed.
If users absolutely need to restrict scoped access, they can
restrict LANDLOCK_ACCESS_FS_MAKE_SOCK. It is a slightly obscure
API, but in line with the "make easy things easy, make hard things
possible" API philosophy. And needing this should be the
exception rather than the norm, after all.
* Consistent behaviour between scoped flags and regular access
rights, also for speculative access rights affecting the existing
scoped flags for signals and abstract UNIX domain sockets.
I know this was a slightly long mail, but I thought long and tried to
be structured. Please let me know what you think.
—Günther
[1] https://lore.kernel.org/all/f07fe41a-96c5-4d3a-9966-35b30b3a71f1@maowtm.org/
^ permalink raw reply
* Re: [PATCH v4 15/17] module: Introduce hash-based integrity checking
From: Thomas Weißschuh @ 2026-02-03 12:59 UTC (permalink / raw)
To: Petr Pavlu
Cc: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Sami Tolvanen,
Daniel Gomez, Paul Moore, James Morris, Serge E. Hallyn,
Jonathan Corbet, Madhavan Srinivasan, Michael Ellerman,
Nicholas Piggin, Naveen N Rao, Mimi Zohar, Roberto Sassu,
Dmitry Kasatkin, Eric Snowberg, Nicolas Schier, Daniel Gomez,
Aaron Tomlin, Christophe Leroy (CS GROUP), Nicolas Schier,
Nicolas Bouchinet, Xiu Jianfeng, Fabian Grünbichler,
Arnout Engelen, Mattia Rizzolo, kpcyrd, Christian Heusel,
Câju Mihai-Drosi, Sebastian Andrzej Siewior, linux-kbuild,
linux-kernel, linux-arch, linux-modules, linux-security-module,
linux-doc, linuxppc-dev, linux-integrity
In-Reply-To: <fab2af64-e396-45f9-8876-feff4002e04b@suse.com>
On 2026-02-03 13:19:20+0100, Petr Pavlu wrote:
> On 1/13/26 1:28 PM, Thomas Weißschuh wrote:
> > The current signature-based module integrity checking has some drawbacks
> > in combination with reproducible builds. Either the module signing key
> > is generated at build time, which makes the build unreproducible, or a
> > static signing key is used, which precludes rebuilds by third parties
> > and makes the whole build and packaging process much more complicated.
> >
> > The goal is to reach bit-for-bit reproducibility. Excluding certain
> > parts of the build output from the reproducibility analysis would be
> > error-prone and force each downstream consumer to introduce new tooling.
> >
> > Introduce a new mechanism to ensure only well-known modules are loaded
> > by embedding a merkle tree root of all modules built as part of the full
> > kernel build into vmlinux.
> >
> > Non-builtin modules can be validated as before through signatures.
> >
> > Normally the .ko module files depend on a fully built vmlinux to be
> > available for modpost validation and BTF generation. With
> > CONFIG_MODULE_HASHES, vmlinux now depends on the modules
> > to build a merkle tree. This introduces a dependency cycle which is
> > impossible to satisfy. Work around this by building the modules during
> > link-vmlinux.sh, after vmlinux is complete enough for modpost and BTF
> > but before the final module hashes are
> >
> > The PKCS7 format which is used for regular module signatures can not
> > represent Merkle proofs, so a new kind of module signature is
> > introduced. As this signature type is only ever used for builtin
> > modules, no compatibility issues can arise.
>
> Nit: The description uses the term "builtin modules" in a misleading
> way. Typically, "builtin modules" refers to modules that are linked
> directly into vmlinux. However, this text uses the term to refer to
> loadable modules that are built together with the main kernel image,
> which is something different.
Agreed. I'll go through everything again, to consistently use "in-tree".
(...)
> > +
> > + while (fgets(line, PATH_MAX, in)) {
> > + struct file_entry *entry;
> > +
> > + fh_list = xreallocarray(fh_list, num_files + 1, sizeof(*fh_list));
>
> It might be useful to not reallocate this array for each file, although
> I don't immediately see that it contributes any significant time to the
> runtime.
The libc implementation should optimize this internally to not actually
grow one elemet at a time. I'd like to keep this as-is.
(...)
Ack to everything else.
^ permalink raw reply
* Re: [PATCH v4 15/17] module: Introduce hash-based integrity checking
From: Thomas Weißschuh @ 2026-02-03 12:55 UTC (permalink / raw)
To: Petr Pavlu
Cc: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Sami Tolvanen,
Daniel Gomez, Paul Moore, James Morris, Serge E. Hallyn,
Jonathan Corbet, Madhavan Srinivasan, Michael Ellerman,
Nicholas Piggin, Naveen N Rao, Mimi Zohar, Roberto Sassu,
Dmitry Kasatkin, Eric Snowberg, Nicolas Schier, Daniel Gomez,
Aaron Tomlin, Christophe Leroy (CS GROUP), Nicolas Schier,
Nicolas Bouchinet, Xiu Jianfeng, Fabian Grünbichler,
Arnout Engelen, Mattia Rizzolo, kpcyrd, Christian Heusel,
Câju Mihai-Drosi, Sebastian Andrzej Siewior, linux-kbuild,
linux-kernel, linux-arch, linux-modules, linux-security-module,
linux-doc, linuxppc-dev, linux-integrity
In-Reply-To: <db1ed045-d7b6-49dc-b111-9fea7c30f8ab@suse.com>
On 2026-01-30 18:06:20+0100, Petr Pavlu wrote:
> On 1/13/26 1:28 PM, Thomas Weißschuh wrote:
> > Normally the .ko module files depend on a fully built vmlinux to be
> > available for modpost validation and BTF generation. With
> > CONFIG_MODULE_HASHES, vmlinux now depends on the modules
> > to build a merkle tree. This introduces a dependency cycle which is
> > impossible to satisfy. Work around this by building the modules during
> > link-vmlinux.sh, after vmlinux is complete enough for modpost and BTF
> > but before the final module hashes are
>
> I wonder if this dependency cycle could be resolved by utilizing the
> split into vmlinux.unstripped and vmlinux that occurred last year.
>
> The idea is to create the following ordering: vmlinux.unstripped ->
> modules -> vmlinux, and to patch in .module_hashes only when building
> the final vmlinux.
>
> This would require the following:
> * Split scripts/Makefile.vmlinux into two Makefiles, one that builds the
> current vmlinux.unstripped and the second one that builds the final
> vmlinux from it.
> * Modify the top Makefile to recognize vmlinux.unstripped and update the
> BTF generation rule 'modules: vmlinux' to
> 'modules: vmlinux.unstripped'.
> * Add the 'vmlinux: modules' ordering in the top Makefile for
> CONFIG_MODULE_HASHES=y.
> * Remove the patching of vmlinux.unstripped in scripts/link-vmlinux.sh
> and instead move it into scripts/Makefile.vmlinux when running objcopy
> to produce the final vmlinux.
>
> I think this approach has two main advantages:
> * CONFIG_MODULE_HASHES can be made orthogonal to
> CONFIG_DEBUG_INFO_BTF_MODULES.
> * All dependencies are expressed at the Makefile level instead of having
> scripts/link-vmlinux.sh invoke 'make -f Makefile modules'.
>
> Below is a rough prototype that applies on top of this series. It is a
> bit verbose due to the splitting of part of scripts/Makefile.vmlinux
> into scripts/Makefile.vmlinux_unstripped.
That looks like a feasible alternative. Before adopting it, I'd like to
hear the preference of the kbuild folks.
> diff --git a/Makefile b/Makefile
> index 841772a5a260..19a3beb82fa7 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1259,7 +1259,7 @@ vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
> vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
> @:
>
> -PHONY += vmlinux
> +PHONY += vmlinux.unstripped vmlinux
> # LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
> # not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
> # unrelated; the decompressors just happen to have the same base name,
> @@ -1270,9 +1270,11 @@ PHONY += vmlinux
> # https://savannah.gnu.org/bugs/?61463
> # For Make > 4.4, the following simple code will work:
> # vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
> -vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
> -vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
> -vmlinux: vmlinux.o $(KBUILD_LDS) modpost
> +vmlinux.unstripped: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
> +vmlinux.unstripped: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
> +vmlinux.unstripped: vmlinux.o $(KBUILD_LDS) modpost
> + $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_unstripped
> +vmlinux: vmlinux.unstripped
> $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
Maybe we could keep them together in a single Makefile,
and instead have different targets in it.
(...)
> @@ -98,70 +44,15 @@ remove-symbols := -w --strip-unneeded-symbol='__mod_device_table__*'
> # To avoid warnings: "empty loadable segment detected at ..." from GNU objcopy,
> # it is necessary to remove the PT_LOAD flag from the segment.
> quiet_cmd_strip_relocs = OBJCOPY $@
> - cmd_strip_relocs = $(OBJCOPY) $(patsubst %,--set-section-flags %=noload,$(remove-section-y)) $< $@; \
> - $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) $(remove-symbols) $@
> + cmd_script_relocs = $(OBJCOPY) $(patsubst %,--set-section-flags %=noload,$(remove-section-y)) $< $@; \
> + $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) \
> + $(remove-symbols) \
> + $(patch-module-hashes) $@
cmd_script_relocs -> cmd_strip_relocs
(...)
^ permalink raw reply
* Re: [PATCH v4 13/17] module: Report signature type to users
From: Thomas Weißschuh @ 2026-02-03 12:44 UTC (permalink / raw)
To: Petr Pavlu
Cc: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Sami Tolvanen,
Daniel Gomez, Paul Moore, James Morris, Serge E. Hallyn,
Jonathan Corbet, Madhavan Srinivasan, Michael Ellerman,
Nicholas Piggin, Naveen N Rao, Mimi Zohar, Roberto Sassu,
Dmitry Kasatkin, Eric Snowberg, Nicolas Schier, Daniel Gomez,
Aaron Tomlin, Christophe Leroy (CS GROUP), Nicolas Schier,
Nicolas Bouchinet, Xiu Jianfeng, Fabian Grünbichler,
Arnout Engelen, Mattia Rizzolo, kpcyrd, Christian Heusel,
Câju Mihai-Drosi, Sebastian Andrzej Siewior, linux-kbuild,
linux-kernel, linux-arch, linux-modules, linux-security-module,
linux-doc, linuxppc-dev, linux-integrity
In-Reply-To: <fd19f9d3-b01c-4cc8-9fd5-642350e7b36b@suse.com>
On 2026-01-29 15:44:31+0100, Petr Pavlu wrote:
> On 1/13/26 1:28 PM, Thomas Weißschuh wrote:
> > The upcoming CONFIG_MODULE_HASHES will introduce a signature type.
> > This needs to be handled by callers differently than PKCS7 signatures.
> >
> > Report the signature type to the caller and let them verify it.
> >
> > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> > ---
> > [...]
> > diff --git a/kernel/module/main.c b/kernel/module/main.c
> > index d65bc300a78c..2a28a0ece809 100644
> > --- a/kernel/module/main.c
> > +++ b/kernel/module/main.c
> > @@ -3348,19 +3348,24 @@ static int module_integrity_check(struct load_info *info, int flags)
> > {
> > bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS |
> > MODULE_INIT_IGNORE_VERMAGIC);
> > + enum pkey_id_type sig_type;
> > size_t sig_len;
> > const u8 *sig;
> > int err = 0;
> >
> > if (IS_ENABLED(CONFIG_MODULE_SIG_POLICY)) {
> > err = mod_split_sig(info->hdr, &info->len, mangled_module,
> > - &sig_len, &sig, "module");
> > + &sig_type, &sig_len, &sig, "module");
> > if (err)
> > return err;
> > }
> >
> > - if (IS_ENABLED(CONFIG_MODULE_SIG))
> > + if (IS_ENABLED(CONFIG_MODULE_SIG) && sig_type == PKEY_ID_PKCS7) {
> > err = module_sig_check(info, sig, sig_len);
> > + } else {
> > + pr_err("module: not signed with expected PKCS#7 message\n");
> > + err = -ENOPKG;
> > + }
>
> The new else branch means that if the user chooses not to configure any
> module integrity policy, they will no longer be able to load any
> modules. I think this entire if-else part should be moved under the
> IS_ENABLED(CONFIG_MODULE_SIG_POLICY) block above, as I'm mentioning on
> patch #12.
Ack.
^ permalink raw reply
* Re: [PATCH v4 12/17] module: Move signature splitting up
From: Thomas Weißschuh @ 2026-02-03 12:42 UTC (permalink / raw)
To: Petr Pavlu
Cc: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Sami Tolvanen,
Daniel Gomez, Paul Moore, James Morris, Serge E. Hallyn,
Jonathan Corbet, Madhavan Srinivasan, Michael Ellerman,
Nicholas Piggin, Naveen N Rao, Mimi Zohar, Roberto Sassu,
Dmitry Kasatkin, Eric Snowberg, Nicolas Schier, Daniel Gomez,
Aaron Tomlin, Christophe Leroy (CS GROUP), Nicolas Schier,
Nicolas Bouchinet, Xiu Jianfeng, Fabian Grünbichler,
Arnout Engelen, Mattia Rizzolo, kpcyrd, Christian Heusel,
Câju Mihai-Drosi, Sebastian Andrzej Siewior, linux-kbuild,
linux-kernel, linux-arch, linux-modules, linux-security-module,
linux-doc, linuxppc-dev, linux-integrity
In-Reply-To: <aa92ce4a-d336-4d03-b87d-1c39b1c553da@suse.com>
On 2026-01-29 15:41:43+0100, Petr Pavlu wrote:
> On 1/13/26 1:28 PM, Thomas Weißschuh wrote:
> > The signature splitting will also be used by CONFIG_MODULE_HASHES.
> >
> > Move it up the callchain, so the result can be reused.
> >
> > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> > ---
> > [...]
> > diff --git a/kernel/module/main.c b/kernel/module/main.c
> > index c09b25c0166a..d65bc300a78c 100644
> > --- a/kernel/module/main.c
> > +++ b/kernel/module/main.c
> > @@ -3346,10 +3346,21 @@ static int early_mod_check(struct load_info *info, int flags)
> >
> > static int module_integrity_check(struct load_info *info, int flags)
> > {
> > + bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS |
> > + MODULE_INIT_IGNORE_VERMAGIC);
> > + size_t sig_len;
> > + const u8 *sig;
> > int err = 0;
> >
> > + if (IS_ENABLED(CONFIG_MODULE_SIG_POLICY)) {
> > + err = mod_split_sig(info->hdr, &info->len, mangled_module,
> > + &sig_len, &sig, "module");
> > + if (err)
> > + return err;
> > + }
> > +
> > if (IS_ENABLED(CONFIG_MODULE_SIG))
> > - err = module_sig_check(info, flags);
> > + err = module_sig_check(info, sig, sig_len);
> >
> > if (err)
> > return err;
>
> I suggest moving the IS_ENABLED(CONFIG_MODULE_SIG) block under the
> new IS_ENABLED(CONFIG_MODULE_SIG_POLICY) section. I realize that
> CONFIG_MODULE_SIG implies CONFIG_MODULE_SIG_POLICY, but I believe this
> change makes it more apparent that this it the case. Otherwise, one
> might for example wonder if sig_len in the module_sig_check() call can
> be undefined.
>
> if (IS_ENABLED(CONFIG_MODULE_SIG_POLICY)) {
> err = mod_split_sig(info->hdr, &info->len, mangled_module,
> &sig_len, &sig, "module");
> if (err)
> return err;
>
> if (IS_ENABLED(CONFIG_MODULE_SIG))
> err = module_sig_check(info, sig, sig_len);
> }
Ack.
^ permalink raw reply
* Re: [PATCH v4 08/17] module: Deduplicate signature extraction
From: Thomas Weißschuh @ 2026-02-03 12:41 UTC (permalink / raw)
To: Petr Pavlu
Cc: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Sami Tolvanen,
Daniel Gomez, Paul Moore, James Morris, Serge E. Hallyn,
Jonathan Corbet, Madhavan Srinivasan, Michael Ellerman,
Nicholas Piggin, Naveen N Rao, Mimi Zohar, Roberto Sassu,
Dmitry Kasatkin, Eric Snowberg, Nicolas Schier, Daniel Gomez,
Aaron Tomlin, Christophe Leroy (CS GROUP), Nicolas Schier,
Nicolas Bouchinet, Xiu Jianfeng, Fabian Grünbichler,
Arnout Engelen, Mattia Rizzolo, kpcyrd, Christian Heusel,
Câju Mihai-Drosi, Sebastian Andrzej Siewior, linux-kbuild,
linux-kernel, linux-arch, linux-modules, linux-security-module,
linux-doc, linuxppc-dev, linux-integrity
In-Reply-To: <52cbbccf-d5b6-4a33-b16a-4a09fe5e64d3@suse.com>
On 2026-01-27 16:20:15+0100, Petr Pavlu wrote:
> On 1/13/26 1:28 PM, Thomas Weißschuh wrote:
(...)
> > int module_sig_check(struct load_info *info, int flags)
> > {
> > - int err = -ENODATA;
> > - const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
> > + int err;
> > const char *reason;
> > const void *mod = info->hdr;
> > + size_t sig_len;
> > + const u8 *sig;
> > bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS |
> > MODULE_INIT_IGNORE_VERMAGIC);
> > - /*
> > - * Do not allow mangled modules as a module with version information
> > - * removed is no longer the module that was signed.
> > - */
> > - if (!mangled_module &&
> > - info->len > markerlen &&
> > - memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
> > - /* We truncate the module to discard the signature */
> > - info->len -= markerlen;
> > - err = mod_verify_sig(mod, info);
> > +
> > + err = mod_split_sig(info->hdr, &info->len, mangled_module, &sig_len, &sig, "module");
> > + if (!err) {
> > + err = verify_pkcs7_signature(mod, info->len, sig, sig_len,
> > + VERIFY_USE_SECONDARY_KEYRING,
> > + VERIFYING_MODULE_SIGNATURE,
> > + NULL, NULL);
> > if (!err) {
> > info->sig_ok = true;
> > return 0;
>
> The patch looks to modify the behavior when mangled_module is true.
>
> Previously, module_sig_check() didn't attempt to extract the signature
> in such a case and treated the module as unsigned. The err remained set
> to -ENODATA and the function subsequently consulted module_sig_check()
> and security_locked_down() to determine an appropriate result.
>
> Newly, module_sig_check() calls mod_split_sig(), which skips the
> extraction of the marker ("~Module signature appended~\n") from the end
> of the module and instead attempts to read it as an actual
> module_signature. The value is then passed to mod_check_sig() which
> should return -EBADMSG. The error is propagated to module_sig_check()
> and treated as fatal, without consulting module_sig_check() and
> security_locked_down().
>
> I think the mangled_module flag should not be passed to mod_split_sig()
> and it should be handled solely by module_sig_check().
Ack.
(...)
> > diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c
> > index 3265d744d5ce..a57342d39b07 100644
> > --- a/security/integrity/ima/ima_modsig.c
> > +++ b/security/integrity/ima/ima_modsig.c
> > @@ -40,44 +40,30 @@ struct modsig {
> > int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
> > struct modsig **modsig)
> > {
> > - const size_t marker_len = strlen(MODULE_SIG_STRING);
> > - const struct module_signature *sig;
> > + size_t buf_len_sz = buf_len;
> > struct modsig *hdr;
> > size_t sig_len;
> > - const void *p;
> > + const u8 *sig;
> > int rc;
> >
> > - if (buf_len <= marker_len + sizeof(*sig))
> > - return -ENOENT;
> > -
> > - p = buf + buf_len - marker_len;
> > - if (memcmp(p, MODULE_SIG_STRING, marker_len))
> > - return -ENOENT;
> > -
> > - buf_len -= marker_len;
> > - sig = (const struct module_signature *)(p - sizeof(*sig));
> > -
> > - rc = mod_check_sig(sig, buf_len, func_tokens[func]);
> > + rc = mod_split_sig(buf, &buf_len_sz, true, &sig_len, &sig, func_tokens[func]);
>
> Passing mangled=true to mod_split_sig() seems incorrect here. It causes
> that the function doesn't properly extract the signature marker at the
> end of the module, no?
Indeed, thanks.
I am thinking about dropping this patch from the series for now.
It was meant for IMA modsig compatibility, which is not part of the
series anymore.
> > if (rc)
> > return rc;
> >
> > - sig_len = be32_to_cpu(sig->sig_len);
> > - buf_len -= sig_len + sizeof(*sig);
> > -
> > /* Allocate sig_len additional bytes to hold the raw PKCS#7 data. */
> > hdr = kzalloc(struct_size(hdr, raw_pkcs7, sig_len), GFP_KERNEL);
> > if (!hdr)
> > return -ENOMEM;
> >
> > hdr->raw_pkcs7_len = sig_len;
> > - hdr->pkcs7_msg = pkcs7_parse_message(buf + buf_len, sig_len);
> > + hdr->pkcs7_msg = pkcs7_parse_message(sig, sig_len);
> > if (IS_ERR(hdr->pkcs7_msg)) {
> > rc = PTR_ERR(hdr->pkcs7_msg);
> > kfree(hdr);
> > return rc;
> > }
> >
> > - memcpy(hdr->raw_pkcs7, buf + buf_len, sig_len);
> > + memcpy(hdr->raw_pkcs7, sig, sig_len);
> >
> > /* We don't know the hash algorithm yet. */
> > hdr->hash_algo = HASH_ALGO__LAST;
> >
^ permalink raw reply
* Re: [PATCH v4 15/17] module: Introduce hash-based integrity checking
From: Petr Pavlu @ 2026-02-03 12:19 UTC (permalink / raw)
To: Thomas Weißschuh
Cc: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Sami Tolvanen,
Daniel Gomez, Paul Moore, James Morris, Serge E. Hallyn,
Jonathan Corbet, Madhavan Srinivasan, Michael Ellerman,
Nicholas Piggin, Naveen N Rao, Mimi Zohar, Roberto Sassu,
Dmitry Kasatkin, Eric Snowberg, Nicolas Schier, Daniel Gomez,
Aaron Tomlin, Christophe Leroy (CS GROUP), Nicolas Schier,
Nicolas Bouchinet, Xiu Jianfeng, Fabian Grünbichler,
Arnout Engelen, Mattia Rizzolo, kpcyrd, Christian Heusel,
Câju Mihai-Drosi, Sebastian Andrzej Siewior, linux-kbuild,
linux-kernel, linux-arch, linux-modules, linux-security-module,
linux-doc, linuxppc-dev, linux-integrity
In-Reply-To: <20260113-module-hashes-v4-15-0b932db9b56b@weissschuh.net>
On 1/13/26 1:28 PM, Thomas Weißschuh wrote:
> The current signature-based module integrity checking has some drawbacks
> in combination with reproducible builds. Either the module signing key
> is generated at build time, which makes the build unreproducible, or a
> static signing key is used, which precludes rebuilds by third parties
> and makes the whole build and packaging process much more complicated.
>
> The goal is to reach bit-for-bit reproducibility. Excluding certain
> parts of the build output from the reproducibility analysis would be
> error-prone and force each downstream consumer to introduce new tooling.
>
> Introduce a new mechanism to ensure only well-known modules are loaded
> by embedding a merkle tree root of all modules built as part of the full
> kernel build into vmlinux.
>
> Non-builtin modules can be validated as before through signatures.
>
> Normally the .ko module files depend on a fully built vmlinux to be
> available for modpost validation and BTF generation. With
> CONFIG_MODULE_HASHES, vmlinux now depends on the modules
> to build a merkle tree. This introduces a dependency cycle which is
> impossible to satisfy. Work around this by building the modules during
> link-vmlinux.sh, after vmlinux is complete enough for modpost and BTF
> but before the final module hashes are
>
> The PKCS7 format which is used for regular module signatures can not
> represent Merkle proofs, so a new kind of module signature is
> introduced. As this signature type is only ever used for builtin
> modules, no compatibility issues can arise.
Nit: The description uses the term "builtin modules" in a misleading
way. Typically, "builtin modules" refers to modules that are linked
directly into vmlinux. However, this text uses the term to refer to
loadable modules that are built together with the main kernel image,
which is something different.
> diff --git a/scripts/modules-merkle-tree.c b/scripts/modules-merkle-tree.c
> new file mode 100644
> index 000000000000..a6ec0e21213b
> --- /dev/null
> +++ b/scripts/modules-merkle-tree.c
> @@ -0,0 +1,467 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Compute hashes for modules files and build a merkle tree.
> + *
> + * Copyright (C) 2025 Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
> + * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net>
> + *
> + */
> +#define _GNU_SOURCE 1
> +#include <arpa/inet.h>
> +#include <err.h>
> +#include <unistd.h>
> +#include <fcntl.h>
> +#include <stdarg.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <stdbool.h>
> +#include <stdlib.h>
> +
> +#include <sys/stat.h>
> +#include <sys/mman.h>
> +
> +#include <openssl/evp.h>
> +#include <openssl/err.h>
> +
> +#include "ssl-common.h"
> +
> +static int hash_size;
> +static EVP_MD_CTX *ctx;
> +
> +struct module_signature {
> + uint8_t algo; /* Public-key crypto algorithm [0] */
> + uint8_t hash; /* Digest algorithm [0] */
> + uint8_t id_type; /* Key identifier type [PKEY_ID_PKCS7] */
> + uint8_t signer_len; /* Length of signer's name [0] */
> + uint8_t key_id_len; /* Length of key identifier [0] */
> + uint8_t __pad[3];
> + uint32_t sig_len; /* Length of signature data */
> +};
> +
> +#define PKEY_ID_MERKLE 3
> +
> +static const char magic_number[] = "~Module signature appended~\n";
It might make sense to put these common structures into a file under
scripts/include/ so they can be shared by both scripts/sign-file.c and
scripts/modules-merkle-tree.c.
> +
> +struct file_entry {
> + char *name;
> + unsigned int pos;
> + unsigned char hash[EVP_MAX_MD_SIZE];
> +};
> +
> +static struct file_entry *fh_list;
> +static size_t num_files;
> +
> +struct leaf_hash {
> + unsigned char hash[EVP_MAX_MD_SIZE];
> +};
> +
> +struct mtree {
> + struct leaf_hash **l;
> + unsigned int *entries;
> + unsigned int levels;
> +};
> +
> +static inline void *xcalloc(size_t n, size_t size)
> +{
> + void *p;
> +
> + p = calloc(n, size);
> + if (!p)
> + errx(1, "Memory allocation failed");
> +
> + return p;
> +}
> +
> +static void *xmalloc(size_t size)
> +{
> + void *p;
> +
> + p = malloc(size);
> + if (!p)
> + errx(1, "Memory allocation failed");
> +
> + return p;
> +}
> +
> +static inline void *xreallocarray(void *oldp, size_t n, size_t size)
> +{
> + void *p;
> +
> + p = reallocarray(oldp, n, size);
> + if (!p)
> + errx(1, "Memory allocation failed");
> +
> + return p;
> +}
> +
> +static inline char *xasprintf(const char *fmt, ...)
> +{
> + va_list ap;
> + char *strp;
> + int ret;
> +
> + va_start(ap, fmt);
> + ret = vasprintf(&strp, fmt, ap);
> + va_end(ap);
> + if (ret == -1)
> + err(1, "Memory allocation failed");
> +
> + return strp;
> +}
I believe it is preferable to use xmalloc() and related functions from
scripts/include/xalloc.h, instead of defining your own variants. If
something is missing in xalloc.h, it can be extended.
> +
> +static unsigned int get_pow2(unsigned int val)
> +{
> + return 31 - __builtin_clz(val);
> +}
> +
> +static unsigned int roundup_pow2(unsigned int val)
> +{
> + return 1 << (get_pow2(val - 1) + 1);
> +}
> +
> +static unsigned int log2_roundup(unsigned int val)
> +{
> + return get_pow2(roundup_pow2(val));
> +}
In the edge case when the kernel is built with only one module, the code
calls log2_roundup(1) -> roundup_pow2(1) -> get_pow2(0) ->
__builtin_clz(0). The return value of __builtin_clz() is undefined if
the input is zero.
> +
> +static void hash_data(void *p, unsigned int pos, size_t size, void *ret_hash)
> +{
> + unsigned char magic = 0x01;
> + unsigned int pos_be;
> +
> + pos_be = htonl(pos);
> +
> + ERR(EVP_DigestInit_ex(ctx, NULL, NULL) != 1, "EVP_DigestInit_ex()");
> + ERR(EVP_DigestUpdate(ctx, &magic, sizeof(magic)) != 1, "EVP_DigestUpdate(magic)");
> + ERR(EVP_DigestUpdate(ctx, &pos_be, sizeof(pos_be)) != 1, "EVP_DigestUpdate(pos)");
> + ERR(EVP_DigestUpdate(ctx, p, size) != 1, "EVP_DigestUpdate(data)");
> + ERR(EVP_DigestFinal_ex(ctx, ret_hash, NULL) != 1, "EVP_DigestFinal_ex()");
> +}
> +
> +static void hash_entry(void *left, void *right, void *ret_hash)
> +{
> + int hash_size = EVP_MD_CTX_get_size_ex(ctx);
Nit: The local variable hash_size can be removed, as the static variable
with the same name should hold the same value.
> + unsigned char magic = 0x02;
> +
> + ERR(EVP_DigestInit_ex(ctx, NULL, NULL) != 1, "EVP_DigestInit_ex()");
> + ERR(EVP_DigestUpdate(ctx, &magic, sizeof(magic)) != 1, "EVP_DigestUpdate(magic)");
> + ERR(EVP_DigestUpdate(ctx, left, hash_size) != 1, "EVP_DigestUpdate(left)");
> + ERR(EVP_DigestUpdate(ctx, right, hash_size) != 1, "EVP_DigestUpdate(right)");
> + ERR(EVP_DigestFinal_ex(ctx, ret_hash, NULL) != 1, "EVP_DigestFinal_ex()");
> +}
> +
> +static void hash_file(struct file_entry *fe)
> +{
> + struct stat sb;
> + int fd, ret;
> + void *mem;
> +
> + fd = open(fe->name, O_RDONLY);
> + if (fd < 0)
> + err(1, "Failed to open %s", fe->name);
> +
> + ret = fstat(fd, &sb);
> + if (ret)
> + err(1, "Failed to stat %s", fe->name);
> +
> + mem = mmap(NULL, sb.st_size, PROT_READ, MAP_SHARED, fd, 0);
> + close(fd);
> +
> + if (mem == MAP_FAILED)
> + err(1, "Failed to mmap %s", fe->name);
Nit: The err() call should be moved immediately after mmap(). In theory,
the interleaving close() could change the errno value, resulting in
err() printing a misleading error message.
> +
> + hash_data(mem, fe->pos, sb.st_size, fe->hash);
> +
> + munmap(mem, sb.st_size);
> +}
> +
> +static struct mtree *build_merkle(struct file_entry *fh, size_t num)
> +{
> + struct mtree *mt;
> + unsigned int le;
> +
> + if (!num)
> + return NULL;
> +
> + mt = xmalloc(sizeof(*mt));
> + mt->levels = log2_roundup(num);
> +
> + mt->l = xcalloc(sizeof(*mt->l), mt->levels);
> +
> + mt->entries = xcalloc(sizeof(*mt->entries), mt->levels);
> + le = num / 2;
> + if (num & 1)
> + le++;
> + mt->entries[0] = le;
> + mt->l[0] = xcalloc(sizeof(**mt->l), le);
> +
> + /* First level of pairs */
> + for (unsigned int i = 0; i < num; i += 2) {
> + if (i == num - 1) {
> + /* Odd number of files, no pair. Hash with itself */
> + hash_entry(fh[i].hash, fh[i].hash, mt->l[0][i / 2].hash);
> + } else {
> + hash_entry(fh[i].hash, fh[i + 1].hash, mt->l[0][i / 2].hash);
> + }
> + }
> + for (unsigned int i = 1; i < mt->levels; i++) {
> + int odd = 0;
> +
> + if (le & 1) {
> + le++;
> + odd++;
> + }
> +
> + mt->entries[i] = le / 2;
> + mt->l[i] = xcalloc(sizeof(**mt->l), le);
l[i] is overallocated. It needs only 'le / 2' entries.
> +
> + for (unsigned int n = 0; n < le; n += 2) {
> + if (n == le - 2 && odd) {
> + /* Odd number of pairs, no pair. Hash with itself */
> + hash_entry(mt->l[i - 1][n].hash, mt->l[i - 1][n].hash,
> + mt->l[i][n / 2].hash);
> + } else {
> + hash_entry(mt->l[i - 1][n].hash, mt->l[i - 1][n + 1].hash,
> + mt->l[i][n / 2].hash);
> + }
> + }
> + le = mt->entries[i];
Nit: It might be helpful to write both the first-level and other-level
loops in the same style to make them easier to understand, perhaps by
clearly separating the number of entries at each level. I suggest
something like the following:
static struct mtree *build_merkle(struct file_entry *fh, size_t num_files)
{
struct mtree *mt;
unsigned int num_cur_le, num_prev_le;
if (!num_files)
return NULL;
mt = xmalloc(sizeof(*mt));
mt->levels = log2_roundup(num_files);
mt->l = xcalloc(sizeof(*mt->l), mt->levels);
mt->entries = xcalloc(sizeof(*mt->entries), mt->levels);
num_cur_le = (num_files + 1) / 2;
mt->entries[0] = num_cur_le;
mt->l[0] = xcalloc(sizeof(**mt->l), num_cur_le);
/* First level of pairs */
for (unsigned int i = 0; i < num_files; i += 2) {
/* Hash the pair, or the last file with itself if it's odd. */
void *right = i + 1 < num_files ? fh[i + 1].hash : fh[i].hash;
hash_entry(fh[i].hash, right, mt->l[0][i / 2].hash);
}
for (unsigned int i = 1; i < mt->levels; i++) {
num_prev_le = num_cur_le;
num_cur_le = (num_prev_le + 1) / 2;
mt->entries[i] = num_cur_le;
mt->l[i] = xcalloc(sizeof(**mt->l), num_cur_le);
for (unsigned int n = 0; n < num_prev_le; n += 2) {
/* Hash the pair, or the last with itself if it's odd. */
void *right = n + 1 < num_prev_le ?
mt->l[i - 1][n + 1].hash :
mt->l[i - 1][n].hash;
hash_entry(mt->l[i - 1][n].hash, right,
mt->l[i][n / 2].hash);
}
}
return mt;
}
> + }
> + return mt;
> +}
> +
> +static void free_mtree(struct mtree *mt)
> +{
> + if (!mt)
> + return;
> +
> + for (unsigned int i = 0; i < mt->levels; i++)
> + free(mt->l[i]);
> +
> + free(mt->l);
> + free(mt->entries);
> + free(mt);
> +}
> +
> +static void write_be_int(int fd, unsigned int v)
> +{
> + unsigned int be_val = htonl(v);
> +
> + if (write(fd, &be_val, sizeof(be_val)) != sizeof(be_val))
> + err(1, "Failed writing to file");
> +}
> +
> +static void write_hash(int fd, const void *h)
> +{
> + ssize_t wr;
> +
> + wr = write(fd, h, hash_size);
> + if (wr != hash_size)
> + err(1, "Failed writing to file");
> +}
Nit: This could be
if (write(fd, h, hash_size) != hash_size)
to keep the style of write_be_int() and write_hash() consistent.
> +
> +static void build_proof(struct mtree *mt, unsigned int n, int fd)
> +{
> + unsigned char cur[EVP_MAX_MD_SIZE];
> + unsigned char tmp[EVP_MAX_MD_SIZE];
> + struct file_entry *fe, *fe_sib;
> +
> + fe = &fh_list[n];
> +
> + if ((n & 1) == 0) {
> + /* No pair, hash with itself */
> + if (n + 1 == num_files)
> + fe_sib = fe;
> + else
> + fe_sib = &fh_list[n + 1];
> + } else {
> + fe_sib = &fh_list[n - 1];
> + }
> + /* First comes the node position into the file */
> + write_be_int(fd, n);
> +
> + if ((n & 1) == 0)
> + hash_entry(fe->hash, fe_sib->hash, cur);
> + else
> + hash_entry(fe_sib->hash, fe->hash, cur);
> +
> + /* Next is the sibling hash, followed by hashes in the tree */
> + write_hash(fd, fe_sib->hash);
> +
> + for (unsigned int i = 0; i < mt->levels - 1; i++) {
> + n >>= 1;
> + if ((n & 1) == 0) {
> + void *h;
> +
> + /* No pair, hash with itself */
> + if (n + 1 == mt->entries[i])
> + h = cur;
> + else
> + h = mt->l[i][n + 1].hash;
> +
> + hash_entry(cur, h, tmp);
> + write_hash(fd, h);
> + } else {
> + hash_entry(mt->l[i][n - 1].hash, cur, tmp);
> + write_hash(fd, mt->l[i][n - 1].hash);
> + }
> + memcpy(cur, tmp, hash_size);
> + }
> +
> + /* After all that, the end hash should match the root hash */
> + if (memcmp(cur, mt->l[mt->levels - 1][0].hash, hash_size))
> + errx(1, "hash mismatch");
> +}
> +
> +static void append_module_signature_magic(int fd, unsigned int sig_len)
> +{
> + struct module_signature sig_info = {
> + .id_type = PKEY_ID_MERKLE,
> + .sig_len = htonl(sig_len),
> + };
> +
> + if (write(fd, &sig_info, sizeof(sig_info)) < 0)
> + err(1, "write(sig_info) failed");
> +
> + if (write(fd, &magic_number, sizeof(magic_number) - 1) < 0)
> + err(1, "write(magic_number) failed");
Nit: Checking that the written size exactly matches the size of the
input data would be safer and consistent with other uses of write() in
write_be_int() and write_hash(). Additionally, it would be good to make
the error messages consistent in all cases.
> +}
> +
> +static void write_merkle_root(struct mtree *mt, const char *fp)
> +{
> + char buf[1024];
> + unsigned int levels;
> + unsigned char *h;
> + FILE *f;
> +
> + if (mt) {
> + levels = mt->levels;
> + h = mt->l[mt->levels - 1][0].hash;
> + } else {
> + levels = 0;
> + h = xcalloc(1, hash_size);
> + }
> +
> + f = fopen(fp, "w");
> + if (!f)
> + err(1, "Failed to create %s", buf);
The last parameter to err() should be fp. The buf variable is then
unused and can be removed.
> +
> + fprintf(f, "#include <linux/module_hashes.h>\n\n");
> + fprintf(f, "const struct module_hashes_root module_hashes_root __module_hashes_section = {\n");
> +
> + fprintf(f, "\t.levels = %u,\n", levels);
> + fprintf(f, "\t.hash = {");
> + for (unsigned int i = 0; i < hash_size; i++) {
> + char *space = "";
> +
> + if (!(i % 8))
> + fprintf(f, "\n\t\t");
> +
> + if ((i + 1) % 8)
> + space = " ";
> +
> + fprintf(f, "0x%02x,%s", h[i], space);
> + }
> + fprintf(f, "\n\t},");
> +
> + fprintf(f, "\n};\n");
> + fclose(f);
Is it ok not to check the return values when writing to this output
file? Other code checks that its output was successful.
> +
> + if (!mt)
> + free(h);
> +}
> +
> +static char *xstrdup_replace_suffix(const char *str, const char *new_suffix)
> +{
> + const char *current_suffix;
> + size_t base_len;
> +
> + current_suffix = strchr(str, '.');
It is safer to use strrchr() in case the module path happens to contain
a dot.
> + if (!current_suffix)
> + errx(1, "No existing suffix in '%s'", str);
> +
> + base_len = current_suffix - str;
> +
> + return xasprintf("%.*s%s", (int)base_len, str, new_suffix);
> +}
> +
> +static void read_modules_order(const char *fname, const char *suffix)
> +{
> + char line[PATH_MAX];
<limits.h> should be included at the top to provide the definition of
PATH_MAX.
> + FILE *in;
> +
> + in = fopen(fname, "r");
> + if (!in)
> + err(1, "fopen(%s)", fname);
Nit: The error message could be "Failed to open %s" to maintain
consistency with a similar error in write_merkle_root().
> +
> + while (fgets(line, PATH_MAX, in)) {
> + struct file_entry *entry;
> +
> + fh_list = xreallocarray(fh_list, num_files + 1, sizeof(*fh_list));
It might be useful to not reallocate this array for each file, although
I don't immediately see that it contributes any significant time to the
runtime.
> + entry = &fh_list[num_files];
> +
> + entry->pos = num_files;
> + entry->name = xstrdup_replace_suffix(line, suffix);
> + hash_file(entry);
> +
> + num_files++;
> + }
> +
> + fclose(in);
> +}
> +
> +static __attribute__((noreturn))
> +void format(void)
> +{
> + fprintf(stderr,
> + "Usage: scripts/modules-merkle-tree <root definition>\n");
The usage string should mention the second parameter, which is the
module suffix.
> + exit(2);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + const EVP_MD *hash_evp;
> + struct mtree *mt;
> +
> + if (argc != 3)
> + format();
> +
> + hash_evp = EVP_get_digestbyname("sha256");
> + ERR(!hash_evp, "EVP_get_digestbyname");
> +
> + ctx = EVP_MD_CTX_new();
> + ERR(!ctx, "EVP_MD_CTX_new()");
> +
> + hash_size = EVP_MD_get_size(hash_evp);
> + ERR(hash_size <= 0, "EVP_get_digestbyname");
> +
> + if (EVP_DigestInit_ex(ctx, hash_evp, NULL) != 1)
> + ERR(1, "EVP_DigestInit_ex()");
> +
> + read_modules_order("modules.order", argv[2]);
> +
> + mt = build_merkle(fh_list, num_files);
> + write_merkle_root(mt, argv[1]);
> + for (unsigned int i = 0; i < num_files; i++) {
> + char *signame;
> + int fd;
> +
> + signame = xstrdup_replace_suffix(fh_list[i].name, ".merkle");
> +
> + fd = open(signame, O_WRONLY | O_CREAT | O_TRUNC, 0644);
> + if (fd < 0)
> + err(1, "Can't create %s", signame);
> +
> + build_proof(mt, i, fd);
> + append_module_signature_magic(fd, lseek(fd, 0, SEEK_CUR));
> + close(fd);
The return code of close() should be checked, otherwise it is
meaningless to check the write() calls in
append_module_signature_magic().
> + }
> +
> + free_mtree(mt);
> + for (unsigned int i = 0; i < num_files; i++)
> + free(fh_list[i].name);
> + free(fh_list);
> +
> + EVP_MD_CTX_free(ctx);
> + return 0;
> +}
--
Thanks,
Petr
^ permalink raw reply
* Re: [PATCH net-next v2 0/4] net: uapi: Provide an UAPI definition of 'struct sockaddr'
From: Thomas Weißschuh @ 2026-02-03 11:42 UTC (permalink / raw)
To: Jakub Kicinski
Cc: Eric Dumazet, Kuniyuki Iwashima, Paolo Abeni, Willem de Bruijn,
David S. Miller, Simon Horman, Shuah Khan, Matthieu Baerts,
Mat Martineau, Geliang Tang, Mickaël Salaün,
Günther Noack, Alexei Starovoitov, Daniel Borkmann,
Jesper Dangaard Brouer, John Fastabend, Stanislav Fomichev,
Andrii Nakryiko, Martin KaFai Lau, Eduard Zingerman, Song Liu,
Yonghong Song, KP Singh, Hao Luo, Jiri Olsa, netdev, linux-kernel,
linux-api, Arnd Bergmann, linux-kselftest, mptcp,
linux-security-module, bpf, libc-alpha, Carlos O'Donell,
Adhemerval Zanella, Rich Felker, klibc, Florian Weimer
In-Reply-To: <20260131092517.6639d84c@kernel.org>
On Sat, Jan 31, 2026 at 09:25:17AM -0800, Jakub Kicinski wrote:
> On Sat, 31 Jan 2026 11:26:32 +0100 Thomas Weißschuh wrote:
> > Jan 30, 2026 17:17:46 Jakub Kicinski <kuba@kernel.org>:
> >
> > > On Fri, 30 Jan 2026 11:34:15 +0100 Thomas Weißschuh wrote:
> > >> Some of them get broken by the new 'struct sockaddr', but some others are
> > >> already broken just by the new transitive inclusion of libc-compat.h.
> > >> So any header starting to use the compatibility machinery may trigger breakage
> > >> in code including UAPI headers before libc header, even for completely new type
> > >> definitions which themselves would not conflict with libc.
> > >
> > > Let's split the uAPI header changes from any selftest changes.
> > > If you're saying the the selftests no longer build after the uAPI
> > > header changes then of course we can't apply the patches.
> >
> > Yes, the selftests don't build anymore after the uAPI changes.
> >
> > "can't apply" as in
> > * "can't apply separately"
> > * "are unacceptable in general"
>
> this one
>
> > * "are too late for this cycle"
> > ?
> >
> > None of this is urgent.
> > We can do the selftests in one cycle and the uAPI in another one.
> > Feel free to pick up the patches as you see fit.
> > (The mptcp changes already go through their tree, so need to be dropped here)
> > I can also resubmit the patches differently if preferred.
>
> The selftests are just a canary in the coalmine. If we break a bunch of
> selftests chances are we'll also break compilation of real applications
> for people. Subjective, but I don't see a sufficient upside here to do
> that.
Okay. We'll have around this inconsistency then.
> FWIW the typelimits change broke compilation of ethtool, we'll see if
> anyone "outside kernel community itself" complains.
Can you point me to that breakage? I was unable to find it.
Thomas
^ permalink raw reply
* Re: [PATCH v4 00/17] module: Introduce hash-based integrity checking
From: David Howells @ 2026-02-03 8:22 UTC (permalink / raw)
To: James Bottomley
Cc: dhowells, Mihai-Drosi Câju, linux, arnd, arnout, atomlin,
bigeasy, chleroy, christian, corbet, coxu, da.gomez, da.gomez,
dmitry.kasatkin, eric.snowberg, f.gruenbichler, jmorris, kpcyrd,
linux-arch, linux-doc, linux-integrity, linux-kbuild,
linux-kernel, linux-modules, linux-security-module, linuxppc-dev,
lkp, maddy, mattia, mcgrof, mpe, nathan, naveen,
nicolas.bouchinet, nicolas.schier, npiggin, nsc, paul, petr.pavlu,
roberto.sassu, samitolvanen, serge, xiujianfeng, zohar
In-Reply-To: <8b12f1d28d3859467c3b5f6bc352038ce7627e54.camel@HansenPartnership.com>
James Bottomley <James.Bottomley@HansenPartnership.com> wrote:
> > There is another issue too: If you have a static private key that you
> > use to sign modules (and probably other things), someone will likely
> > give you a GPL request to get it.
>
> The SFC just lost that exact point in the Vizio trial, so I think
> you're wrong on this under US law at least. There's no general ability
> under GPLv2 to demand long lived signing keys.
Cool :-). I just know that I've been sent GPL requests for kernel keys.
David
^ permalink raw reply
* Re: [PATCH v4 00/17] module: Introduce hash-based integrity checking
From: James Bottomley @ 2026-02-03 8:18 UTC (permalink / raw)
To: David Howells, Mihai-Drosi Câju
Cc: linux, arnd, arnout, atomlin, bigeasy, chleroy, christian, corbet,
coxu, da.gomez, da.gomez, dmitry.kasatkin, eric.snowberg,
f.gruenbichler, jmorris, kpcyrd, linux-arch, linux-doc,
linux-integrity, linux-kbuild, linux-kernel, linux-modules,
linux-security-module, linuxppc-dev, lkp, maddy, mattia, mcgrof,
mpe, nathan, naveen, nicolas.bouchinet, nicolas.schier, npiggin,
nsc, paul, petr.pavlu, roberto.sassu, samitolvanen, serge,
xiujianfeng, zohar
In-Reply-To: <2316630.1769965788@warthog.procyon.org.uk>
On Sun, 2026-02-01 at 17:09 +0000, David Howells wrote:
> Mihai-Drosi Câju <mcaju95@gmail.com> wrote:
>
> > > The current signature-based module integrity checking has some
> > > drawbacks
> > in combination with reproducible builds. Either the module signing
> > key is generated at build time, which makes the build
> > unreproducible, or a static signing key is used, which precludes
> > rebuilds by third parties and makes the whole build and packaging
> > process much more complicated.
>
> There is another issue too: If you have a static private key that you
> use to sign modules (and probably other things), someone will likely
> give you a GPL request to get it.
The SFC just lost that exact point in the Vizio trial, so I think
you're wrong on this under US law at least. There's no general ability
under GPLv2 to demand long lived signing keys.
Regards,
James
^ permalink raw reply
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