kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths
Published Nov 12, 2025
7.8
HIGHCVSS 3.1
EPSS 0.14%
Description
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 products
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- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version
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- Version 5.18StatusaffectedConstraints-
- Version 0StatusunaffectedConstraints<5.18
- Version 6.1.157StatusunaffectedConstraints<=6.1.*
- Version 6.12.54StatusunaffectedConstraints<=6.12.*
- Version 6.17.4StatusunaffectedConstraints<=6.17.*
- Version 6.18StatusunaffectedConstraints<=*
- Version 6.6.113StatusunaffectedConstraints<=6.6.*
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
| ||||||||||||||||||||||||
| Linux | Linux | affected |
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No data.
No data.
Red Hat Enterprise Linux 10
kernel
Affected
Red Hat Enterprise Linux 6
kernel
Out of support scope
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Not affected
Red Hat Enterprise Linux 8
kernel-rt
Not affected
Red Hat Enterprise Linux 9
kernel
Affected
Red Hat Enterprise Linux 9
kernel-rt
Affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel | Affected | n/a |
| Red Hat Enterprise Linux 9 | kernel-rt | Affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
References (11)
- https://access.redhat.com/security/cve/CVE-2025-40201 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2414726 Issue Tracking
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-150373 Advisory
- https://git.kernel.org/stable/c/132f827e7bac7373e1522e89709d70b43cae5342
- https://git.kernel.org/stable/c/19b45c84bd9fd42fa97ff80c6350d604cb871c75
- https://git.kernel.org/stable/c/1bc0d9315ef5296abb2c9fd840336255850ded18
- https://git.kernel.org/stable/c/6796412decd2d8de8ec708213bbc958fab72f143
- https://git.kernel.org/stable/c/a15f37a40145c986cdf289a4b88390f35efdecc4
- https://lore.kernel.org/linux-cve-announce/2025111246-CVE-2025-40201-b8fe@gregkh/T
- https://nvd.nist.gov/vuln/detail/CVE-2025-40201
- https://www.cve.org/CVERecord?id=CVE-2025-40201
Change history (0)
No recorded changes yet.