GHSA-892H-JC8G-4JRG
Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-11 21:31In the Linux kernel, the following vulnerability has been resolved:
sunrpc: fix use-after-free in __rpc_clnt_handle_event and __rpc_clnt_remove_pipedir
Normal client creation goes through rpc_setup_pipedir(), which records clnt->pipefs_sb, but the mount-event path in __rpc_clnt_handle_event() calls rpc_setup_pipedir_sb() directly and never refreshes that field. The umount path also removes the directory without clearing clnt->pipefs_sb.
After a late pipefs mount or any remount, rpc_clnt_remove_pipedir() compares the current superblock against a stale pipefs_sb pointer and skips cleanup, leaving pipefs dentries whose inode private data still points at a freed rpc_clnt, leading to a potential use-after-free during subsequent rpc_info_open() or rpc_show_info() calls.
Fix this by properly updating clnt->pipefs_sb upon mount events and clearing it during unmount or failure paths.
{
"affected": [],
"aliases": [
"CVE-2026-89543"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-11T20:19:37Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: fix use-after-free in __rpc_clnt_handle_event and __rpc_clnt_remove_pipedir\n\nNormal client creation goes through rpc_setup_pipedir(), which records\nclnt-\u003epipefs_sb, but the mount-event path in __rpc_clnt_handle_event()\ncalls rpc_setup_pipedir_sb() directly and never refreshes that field.\nThe umount path also removes the directory without clearing\nclnt-\u003epipefs_sb.\n\nAfter a late pipefs mount or any remount, rpc_clnt_remove_pipedir()\ncompares the current superblock against a stale pipefs_sb pointer and\nskips cleanup, leaving pipefs dentries whose inode private data still\npoints at a freed rpc_clnt, leading to a potential use-after-free during\nsubsequent rpc_info_open() or rpc_show_info() calls.\n\nFix this by properly updating clnt-\u003epipefs_sb upon mount events and\nclearing it during unmount or failure paths.",
"id": "GHSA-892h-jc8g-4jrg",
"modified": "2026-09-11T21:31:31Z",
"published": "2026-09-11T21:31:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89543"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/932a8cf6abb2b2f8677b79153a823108d8861fe2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cdf7a233cb94774b0e7df42d9157077983f5022c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e769fcde3cc73e847b1eb3acd40c04a291cb0c0c"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.