CVE-2025-40201
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.
Affected versions
Linux kernel versions
5.18
and later are affected. Fixed in
6.1.157,
6.6.113,
6.12.54,
6.17.4,
6.18
and their respective stable series.
References
The following references provide additional information about CVE-2025-40201 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/132f827e7bac7373e1522e89709d70b43cae5342
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PatchKernel patch commithttps://git.kernel.org/stable/c/19b45c84bd9fd42fa97ff80c6350d604cb871c75
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PatchKernel patch commithttps://git.kernel.org/stable/c/1bc0d9315ef5296abb2c9fd840336255850ded18
Frequently asked questions
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What is CVE-2025-40201?
CVE-2025-40201 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.18 onward and has been patched in 6.1.157, 6.6.113, 6.12.54 and others. CVE-2025-40201 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2025-40201?
Yes — CVE-2025-40201 has been patched. Fixed versions include 6.1.157, 6.6.113, 6.12.54 and others. If you are running Linux kernel 5.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-40201 actively exploited?
No — CVE-2025-40201 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.