ghsa-r7m4-wpp2-9f3x
Vulnerability from github
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": [],
"aliases": [
"CVE-2025-40201"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-11-12T22:15:47Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nkernel/sys.c: fix the racy usage of task_lock(tsk-\u003egroup_leader) in sys_prlimit64() paths\n\nThe usage of task_lock(tsk-\u003egroup_leader) in sys_prlimit64()-\u003edo_prlimit()\npath is very broken.\n\nsys_prlimit64() does get_task_struct(tsk) but this only protects task_struct\nitself. If tsk != current and tsk is not a leader, this process can exit/exec\nand task_lock(tsk-\u003egroup_leader) may use the already freed task_struct.\n\nAnother problem is that sys_prlimit64() can race with mt-exec which changes\n-\u003egroup_leader. In this case do_prlimit() may take the wrong lock, or (worse)\n-\u003egroup_leader may change between task_lock() and task_unlock().\n\nChange sys_prlimit64() to take tasklist_lock when necessary. This is not\nnice, but I don\u0027t see a better fix for -stable.",
"id": "GHSA-r7m4-wpp2-9f3x",
"modified": "2025-11-13T00:30:18Z",
"published": "2025-11-13T00:30:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40201"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/132f827e7bac7373e1522e89709d70b43cae5342"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/19b45c84bd9fd42fa97ff80c6350d604cb871c75"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1bc0d9315ef5296abb2c9fd840336255850ded18"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6796412decd2d8de8ec708213bbc958fab72f143"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a15f37a40145c986cdf289a4b88390f35efdecc4"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.