CVE-2025-40201kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths
Updated under an hour ago ()
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In the Linux kernel, the following vulnerability has been resolved: kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths The usage of task_lock(tsk->group_leader) in sys_prlimit64()->do_prlimit() path is very broken. sys_prlimit64() does get_task_struct(tsk) but this only protects task_struct itself. If tsk != current and tsk is not a leader, this process can exit/exec and task_lock(tsk->group_leader) may use the already freed task_struct. Another problem is that sys_prlimit64() can race with mt-exec which changes ->group_leader. In this case do_prlimit() may take the wrong lock, or (worse) ->group_leader may change between task_lock() and task_unlock(). Change sys_prlimit64() to take tasklist_lock when necessary. This is not nice, but I don't see a better fix for -stable.
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Deferred
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | 18c91bb2d87268d23868bf13508f5bc9cf04e89a builds before 1bc0d9315ef5296abb2c9fd840336255850ded18; from 18c91bb2d87268d23868bf13508f5bc9cf04e89a before 132f827e7bac7373e1522e89709d70b43cae5342; from 18c91bb2d87268d23868bf13508f5bc9cf04e89a before 19b45c84bd9fd42fa97ff80c6350d604cb871c75; from 18c91bb2d87268d23868bf13508f5bc9cf04e89a before 6796412decd2d8de8ec708213bbc958fab72f143; from 18c91bb2d87268d23868bf13508f5bc9cf04e89a before a15f37a40145c986cdf289a4b88390f35efdecc4 | CNA record |
References
- https://git.kernel.org/stable/c/1bc0d9315ef5296abb2c9fd840336255850ded18
- https://git.kernel.org/stable/c/132f827e7bac7373e1522e89709d70b43cae5342
- https://git.kernel.org/stable/c/19b45c84bd9fd42fa97ff80c6350d604cb871c75
- https://git.kernel.org/stable/c/6796412decd2d8de8ec708213bbc958fab72f143
- https://git.kernel.org/stable/c/a15f37a40145c986cdf289a4b88390f35efdecc4
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.