kernel/git/stable/linux-stable.git/security/landlock, branch linux-6.16.y

landlock: opened file never has a negative dentry

2025-08-20T16:40:55+00:00

[ Upstream commit d1832e648d2be564e4b5e357f94d0f33156590dc ] Reviewed-by: Christian Brauner Acked-by: Mickaël Salaün Signed-off-by: Al Viro Signed-off-by: Sasha Levin

landlock: Fix warning from KUnit tests

2025-08-15T14:38:21+00:00

[ Upstream commit e0a69cf2c03e61bd8069becb97f66c173d0d1fa1 ] get_id_range() expects a positive value as first argument but get_random_u8() can return 0. Fix this by clamping it. Validated by running the test in a for loop for 1000 times. Note that MAX() is wrong as it is only supposed to be used for constants, but max() is good here. [..] ok 9 test_range2_rand1 [..] ok 10 test_range2_rand2 [..] ok 11 test_range2_rand15 [..] ------------[ cut here ]------------ [..] WARNING: CPU: 6 PID: 104 at security/landlock/id.c:99 test_range2_rand16 (security/landlock/id.c:99 (discriminator 1) security/landlock/id.c:234 (discriminator 1)) [..] Modules linked in: [..] CPU: 6 UID: 0 PID: 104 Comm: kunit_try_catch Tainted: G N 6.16.0-rc1-dev-00001-g314a2f98b65f #1 PREEMPT(undef) [..] Tainted: [N]=TEST [..] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [..] RIP: 0010:test_range2_rand16 (security/landlock/id.c:99 (discriminator 1) security/landlock/id.c:234 (discriminator 1)) [..] Code: 49 c7 c0 10 70 30 82 4c 89 ff 48 c7 c6 a0 63 1e 83 49 c7 45 a0 e0 63 1e 83 e8 3f 95 17 00 e9 1f ff ff ff 0f 0b e9 df fd ff ff <0f> 0b ba 01 00 00 00 e9 68 fe ff ff 49 89 45 a8 49 8d 4d a0 45 31 [..] RSP: 0000:ffff888104eb7c78 EFLAGS: 00010246 [..] RAX: 0000000000000000 RBX: 000000000870822c RCX: 0000000000000000 ^^^^^^^^^^^^^^^^ [..] [..] Call Trace: [..] [..] ---[ end trace 0000000000000000 ]--- [..] ok 12 test_range2_rand16 [..] # landlock_id: pass:12 fail:0 skip:0 total:12 [..] # Totals: pass:12 fail:0 skip:0 total:12 [..] ok 1 landlock_id Fixes: d9d2a68ed44b ("landlock: Add unique ID generator") Signed-off-by: Tingmao Wang Link: https://lore.kernel.org/r/73e28efc5b8cc394608b99d5bc2596ca917d7c4a.1750003733.git.m@maowtm.org [mic: Minor cosmetic improvements] Signed-off-by: Mickaël Salaün Signed-off-by: Sasha Levin

landlock: Improve bit operations in audit code

2025-05-12T09:38:53+00:00

Use the BIT() and BIT_ULL() macros in the new audit code instead of explicit shifts to improve readability. Use bitmask instead of modulo operation to simplify code. Add test_range1_rand15() and test_range2_rand15() KUnit tests to improve get_id_range() coverage. Signed-off-by: Günther Noack Link: https://lore.kernel.org/r/20250512093732.1408485-1-mic@digikod.net Signed-off-by: Mickaël Salaün

landlock: Remove KUnit test that triggers a warning

2025-05-03T06:55:42+00:00

A KUnit test checking boundaries triggers a canary warning, which may be disturbing. Let's remove this test for now. Hopefully, KUnit will soon get support for suppressing warning backtraces [1]. Cc: Alessandro Carminati Cc: Andrew Morton Cc: Günther Noack Reported-by: Tingmao Wang Closes: https://lore.kernel.org/r/20250327213807.12964-1-m@maowtm.org Link: https://lore.kernel.org/r/20250425193249.78b45d2589575c15f483c3d8@linux-foundation.org [1] Link: https://lore.kernel.org/r/20250503065359.3625407-1-mic@digikod.net Signed-off-by: Mickaël Salaün

landlock: Fix documentation for landlock_restrict_self(2)

2025-04-17T09:09:10+00:00

Fix, deduplicate, and improve rendering of landlock_restrict_self(2)'s flags documentation. The flags are now rendered like the syscall's parameters and description. Cc: Günther Noack Cc: Paul Moore Link: https://lore.kernel.org/r/20250416154716.1799902-2-mic@digikod.net Signed-off-by: Mickaël Salaün

landlock: Fix documentation for landlock_create_ruleset(2)

2025-04-17T09:09:07+00:00

Move and fix the flags documentation, and improve formatting. It makes more sense and it eases maintenance to document syscall flags in landlock.h, where they are defined. This is already the case for landlock_restrict_self(2)'s flags. The flags are now rendered like the syscall's parameters and description. Cc: Günther Noack Cc: Paul Moore Link: https://lore.kernel.org/r/20250416154716.1799902-1-mic@digikod.net Signed-off-by: Mickaël Salaün

landlock: Log the TGID of the domain creator

2025-04-11T10:53:17+00:00

As for other Audit's "pid" fields, Landlock should use the task's TGID instead of its TID. Fix this issue by keeping a reference to the TGID of the domain creator. Existing tests already check for the PID but only with the thread group leader, so always the TGID. A following patch adds dedicated tests for non-leader thread. Remove the current_real_cred() check which does not make sense because we only reference a struct pid, whereas a previous version did reference a struct cred instead. Cc: Christian Brauner Cc: Paul Moore Reviewed-by: Günther Noack Link: https://lore.kernel.org/r/20250410171725.1265860-1-mic@digikod.net Signed-off-by: Mickaël Salaün

landlock: Remove incorrect warning

2025-04-08T17:18:20+00:00

landlock_put_hierarchy() can be called when an error occurs in landlock_merge_ruleset() due to insufficient memory. In this case, the domain's audit details might not have been allocated yet, which would cause landlock_free_hierarchy_details() to print a warning (but still safely handle this case). We could keep the WARN_ON_ONCE(!hierarchy) but it's not worth it for this kind of function, so let's remove it entirely. Cc: Paul Moore Reported-by: syzbot+8bca99e91de7e060e4ea@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20250331104709.897062-1-mic@digikod.net Reviewed-by: Günther Noack Signed-off-by: Mickaël Salaün

Merge tag 'landlock-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux

2025-03-28T19:37:13+00:00

Pull landlock updates from Mickaël Salaün: "This brings two main changes to Landlock: - A signal scoping fix with a new interface for user space to know if it is compatible with the running kernel. - Audit support to give visibility on why access requests are denied, including the origin of the security policy, missing access rights, and description of object(s). This was designed to limit log spam as much as possible while still alerting about unexpected blocked access. With these changes come new and improved documentation, and a lot of new tests" * tag 'landlock-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux: (36 commits) landlock: Add audit documentation selftests/landlock: Add audit tests for network selftests/landlock: Add audit tests for filesystem selftests/landlock: Add audit tests for abstract UNIX socket scoping selftests/landlock: Add audit tests for ptrace selftests/landlock: Test audit with restrict flags selftests/landlock: Add tests for audit flags and domain IDs selftests/landlock: Extend tests for landlock_restrict_self(2)'s flags selftests/landlock: Add test for invalid ruleset file descriptor samples/landlock: Enable users to log sandbox denials landlock: Add LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF landlock: Add LANDLOCK_RESTRICT_SELF_LOG_*_EXEC_* flags landlock: Log scoped denials landlock: Log TCP bind and connect denials landlock: Log truncate and IOCTL denials landlock: Factor out IOCTL hooks landlock: Log file-related denials landlock: Log mount-related denials landlock: Add AUDIT_LANDLOCK_DOMAIN and log domain status landlock: Add AUDIT_LANDLOCK_ACCESS and log ptrace denials ...

landlock: Add LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF

2025-03-26T12:59:43+00:00

Add LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF for the case of sandboxer tools, init systems, or runtime containers launching programs sandboxing themselves in an inconsistent way. Setting this flag should only depends on runtime configuration (i.e. not hardcoded). We don't create a new ruleset's option because this should not be part of the security policy: only the task that enforces the policy (not the one that create it) knows if itself or its children may request denied actions. This is the first and only flag that can be set without actually restricting the caller (i.e. without providing a ruleset). Extend struct landlock_cred_security with a u8 log_subdomains_off. struct landlock_file_security is still 16 bytes. Cc: Günther Noack Cc: Paul Moore Closes: https://github.com/landlock-lsm/linux/issues/3 Link: https://lore.kernel.org/r/20250320190717.2287696-19-mic@digikod.net [mic: Fix comment] Signed-off-by: Mickaël Salaün