GHSA-M4WQ-7WV4-XPQ8
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33In the Linux kernel, the following vulnerability has been resolved:
sunrpc: harden rq_procinfo lifecycle to prevent double-free
The svc_release_rqst() function executes the callback inside rqstp->rq_procinfo->pc_release. However, if a worker thread begins processing a new request and encounters an early error path (e.g., unsupported protocol, short frame, or bad auth) before a valid rq_procinfo is installed, a stale release hook can be re-triggered against reused state from the previous RPC, resulting in a double-free or use-after-free vulnerability.
Harden the lifecycle of rq_procinfo by: 1. Ensuring svc_release_rqst() always clears rq_procinfo after the optional pc_release() call, regardless of whether the hook exists. 2. Explicitly clearing rq_procinfo at request entry in svc_process() before any early decode or drop paths. 3. Ensuring svc_process_bc() does the same at backchannel entry.
This guarantees that error flows will not encounter a non-NULL stale rq_procinfo pointer when there is nothing to release.
{
"affected": [],
"aliases": [
"CVE-2026-72220"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:21:40Z",
"severity": "CRITICAL"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: harden rq_procinfo lifecycle to prevent double-free\n\nThe svc_release_rqst() function executes the callback inside\nrqstp-\u003erq_procinfo-\u003epc_release. However, if a worker thread begins\nprocessing a new request and encounters an early error path (e.g.,\nunsupported protocol, short frame, or bad auth) before a valid\nrq_procinfo is installed, a stale release hook can be re-triggered\nagainst reused state from the previous RPC, resulting in a double-free\nor use-after-free vulnerability.\n\nHarden the lifecycle of rq_procinfo by:\n1. Ensuring svc_release_rqst() always clears rq_procinfo after the\n optional pc_release() call, regardless of whether the hook exists.\n2. Explicitly clearing rq_procinfo at request entry in svc_process()\n before any early decode or drop paths.\n3. Ensuring svc_process_bc() does the same at backchannel entry.\n\nThis guarantees that error flows will not encounter a non-NULL stale\nrq_procinfo pointer when there is nothing to release.",
"id": "GHSA-m4wq-7wv4-xpq8",
"modified": "2026-08-17T06:33:16Z",
"published": "2026-08-15T06:32:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72220"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/18d216788bef06332ff8901670ecf1ed8f6eb614"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/31ba490c02d476a5e4f90b8845932ac9db8aa71b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/66014ab165cb01bfef5836939412a8ef98d5d5ff"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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.