nfsd: fix fcache_disposal UAF by inlining dispose state into nfsd_net
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 5.11, 5.16, 6.6.160, 6.12.114, 6.18.51, and 1 more
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix fcache_disposal UAF by inlining dispose state into nfsd_net nfsd_file_dispose_list_delayed() defers fput() to nfsd service threads via a per-net freeme queue, preventing the shrinker and GC worker from bearing the cost of closing files (see ffb402596147). However, the queue lives in a separately-allocated struct nfsd_fcache_disposal that is freed by nfsd_free_fcache_disposal_net() during per-net teardown. The global shrinker, laundrette, and fsnotify callbacks can still be inside nfsd_file_dispose_list_delayed() dereferencing that pointer, causing a use-after-free. Inline the spinlock and freeme list directly into struct nfsd_net (as fcache_dispose_lock and fcache_dispose_list), eliminating the separately allocated struct nfsd_fcache_disposal entirely. These fields now have the same lifetime as the net namespace itself, so there is no dangling pointer to chase. nfsd_file_cache_start_net() now just initializes the inline fields and cannot fail due to allocation. nfsd_file_cache_shutdown_net() drains the inline list directly instead of freeing a separate struct. The alloc/free helpers are removed.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 1463b38e7cf34d4cc60f41daff459ad807b2e408 · fixed in e6c3a43d0a41f03abae3764fc82a59369360c7e0; From 1463b38e7cf34d4cc60f41daff459ad807b2e408 · fixed in 9c8ac7c2b9b150e13b7ad0d0fae54f17747dce67; From 1463b38e7cf34d4cc60f41daff459ad807b2e408 · fixed in ba0ee9e04b7a0356c28d5a2fe445db675d24e572; From 1463b38e7cf34d4cc60f41daff459ad807b2e408 · fixed in cadc9036d5a8209f89e7026ddba7cfb1c716b03c; From 1463b38e7cf34d4cc60f41daff459ad807b2e408 · fixed in bbf13732f74351d21c5e0e8dd9bd8e1c48dc35d4; From 5.10.220 · fixed in 5.11; From 5.15.154 · fixed in 5.16
- Linux Linux
5.17
- KernelLinux
From 5.17.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.114; From 6.13.0 · fixed in 6.18.51; From 6.19.0 · fixed in 7.2.4