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.
Metrics
Affected Vendors & Products
No advisories yet.
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Mon, 14 Sep 2026 12:30:00 +0000
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Sun, 13 Sep 2026 06:45:00 +0000
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| Metrics |
cvssV3_1
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cvssV3_1
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Sat, 12 Sep 2026 12:15:00 +0000
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| Weaknesses | CWE-825 | |
| References |
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| Metrics |
threat_severity
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cvssV3_1
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Fri, 11 Sep 2026 23:45:00 +0000
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| 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. | |
| Title | smack: fix cred UAF in smack_file_send_sigiotask() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
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Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-14T11:58:55.805Z
Reserved: 2026-08-26T14:34:25.802Z
Link: CVE-2026-80928
No data.
Status : Received
Published: 2026-09-11T20:18:56.513
Modified: 2026-09-14T13:18:49.050
Link: CVE-2026-80928
OpenCVE Enrichment
Updated: 2026-09-13T00:45:17Z