Paper/Archive/CVE-2026-72220

CVE-2026-72220

Linux Linux — sunrpc: harden rq_procinfo lifecycle to prevent double-free

Description · from the CVE record

In 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

ProductAffectedFixed inSource
Linuxd9adbb6e10bf7d4223d3d521ede1b2052903bc5e – < 66014ab165cb01bfef5836939412a8ef98d5d5ff66014ab165cb01bfef5836939412a8ef98d5d5ffCNA
Linuxd9adbb6e10bf7d4223d3d521ede1b2052903bc5e – < 31ba490c02d476a5e4f90b8845932ac9db8aa71b31ba490c02d476a5e4f90b8845932ac9db8aa71bCNA
Linuxd9adbb6e10bf7d4223d3d521ede1b2052903bc5e – < 18d216788bef06332ff8901670ecf1ed8f6eb61418d216788bef06332ff8901670ecf1ed8f6eb614CNA
Linux6.186.18.40CNA

Scores by source

Linux (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

refgit.kernel.org/stable/c/66014ab165cb01bfef5836939412a8ef98d5d5ffrefgit.kernel.org/stable/c/31ba490c02d476a5e4f90b8845932ac9db8aa71brefgit.kernel.org/stable/c/18d216788bef06332ff8901670ecf1ed8f6eb614