ghsa-4mrm-9mrj-crwx
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
blk-cgroup: dropping parent refcount after pd_free_fn() is done
Some cgroup policies will access parent pd through child pd even after pd_offline_fn() is done. If pd_free_fn() for parent is called before child, then UAF can be triggered. Hence it's better to guarantee the order of pd_free_fn().
Currently refcount of parent blkg is dropped in __blkg_release(), which is before pd_free_fn() is called in blkg_free_work_fn() while blkg_free_work_fn() is called asynchronously.
This patch make sure pd_free_fn() called from removing cgroup is ordered by delaying dropping parent refcount after calling pd_free_fn() for child.
BTW, pd_free_fn() will also be called from blkcg_deactivate_policy() from deleting device, and following patches will guarantee the order.
{
"affected": [],
"aliases": [
"CVE-2023-54107"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-24T13:16:12Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nblk-cgroup: dropping parent refcount after pd_free_fn() is done\n\nSome cgroup policies will access parent pd through child pd even\nafter pd_offline_fn() is done. If pd_free_fn() for parent is called\nbefore child, then UAF can be triggered. Hence it\u0027s better to guarantee\nthe order of pd_free_fn().\n\nCurrently refcount of parent blkg is dropped in __blkg_release(), which\nis before pd_free_fn() is called in blkg_free_work_fn() while\nblkg_free_work_fn() is called asynchronously.\n\nThis patch make sure pd_free_fn() called from removing cgroup is ordered\nby delaying dropping parent refcount after calling pd_free_fn() for\nchild.\n\nBTW, pd_free_fn() will also be called from blkcg_deactivate_policy()\nfrom deleting device, and following patches will guarantee the order.",
"id": "GHSA-4mrm-9mrj-crwx",
"modified": "2025-12-24T15:30:38Z",
"published": "2025-12-24T15:30:38Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-54107"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c7241babf0855d8a6180cd1743ff0ec34de40b4e"
}
],
"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.