CVE-2026-80928

smack: fix cred UAF in smack_file_send_sigiotask()

State: Published
Severity: 7.8 High
Published: Sep 11, 2026
Updated: Oct 19, 2026
Reserved: Aug 26, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

smack: fix cred UAF in smack_file_send_sigiotask()

When inspecting the credentials of another task, objective credentials (->real_cred, accessed with __task_cred()) must always be used.

Accessing ->cred on a non-current task is forbidden unless that task is being created or destroyed; a task is allowed to change its own ->cred pointer with no synchronization, and changing ->cred should only affect the current syscall.

smack_file_send_sigiotask() was accessing both sets of credentials: First tsk->cred, then __task_cred(tsk).

Fix it, always access the objective credentials here.

I have tested that this bug can lead to a KASAN-reported UAF of struct cred in smack_file_send_sigiotask(), and that this fix prevents the race.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before a512366d84e134a9eefc2cc40eeb6e80e2ec162cAffected 3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before 7c7fe043f3099d0d35002b248967f75e55345b93Affected 3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before f9c7b1f2b9d8f4176d2632743f51400855978aceAffected 3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before b5bcf3adfa27279da4401ab8f1e1a706601a92beAffected 3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before ed64aa505875a3b4defd504ee8e59e1949246a62Affected 3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before b791401bf389a1546a830d2b381ca60fe94c7870Affected 3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before fedc88e38ce979a720cd2de042578cb5df3dc8deAffected
LinuxLinux	2.6.29Affected before 2.6.29Not affected 5.15.221 through 5.15.Not affected 6.1.188 through 6.1.Not affected 6.6.157 through 6.6.Not affected 6.12.109 through 6.12.Not affected 6.18.50 through 6.18.Not affected 7.2.4 through 7.2.Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before a512366d84e134a9eefc2cc40eeb6e80e2ec162cAffected
3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before 7c7fe043f3099d0d35002b248967f75e55345b93Affected
3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before f9c7b1f2b9d8f4176d2632743f51400855978aceAffected
3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before b5bcf3adfa27279da4401ab8f1e1a706601a92beAffected
3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before ed64aa505875a3b4defd504ee8e59e1949246a62Affected
3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before b791401bf389a1546a830d2b381ca60fe94c7870Affected
3b11a1decef07c19443d24ae926982bc8ec9f4c0 to before fedc88e38ce979a720cd2de042578cb5df3dc8deAffected

LinuxLinux

2.6.29Affected
before 2.6.29Not affected
5.15.221 through 5.15.*Not affected
6.1.188 through 6.1.*Not affected
6.6.157 through 6.6.*Not affected
6.12.109 through 6.12.*Not affected
6.18.50 through 6.18.*Not affected
7.2.4 through 7.2.*Not affected
7.3 and laterNot affected

References

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