{"id":"CVE-2026-74315","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74315","summary":"lockd: Avoid hashing uninitialized bytes in nlm4svc_lookup_file()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nlockd: Avoid hashing uninitialized bytes in nlm4svc_lookup_file()\n\nfile_hash() digests the first LOCKD_FH_HASH_SIZE bytes of\nnfs_fh.data when bucketing nlm_files[], independent of fh.size.\nCommit 3de744ee4e45 (\"lockd: Use xdrgen XDR functions for the\nNLMv4 TEST procedure\") set .pc_argzero to zero for the converted\nprocedures and moved file-handle population into\nnlm4svc_lookup_file(), which copies only xdr_lock->fh.len bytes\ninto lock->fh.data.\n\nWhen an NLMv4 client presents a file handle shorter than\nLOCKD_FH_HASH_SIZE, bytes fh.len..31 retain whatever the argument\nbuffer held from an earlier request.  The same wire handle then\nhashes to different buckets across calls; nlm_lookup_file() misses\nthe existing nlm_file entry, and lock-state lookups fail.\n\nZero only the tail bytes that file_hash() would otherwise consume.\nHandles of LOCKD_FH_HASH_SIZE or larger already populate every byte\nthat file_hash() reads.","published":"2026-08-15T05:58:13.504Z","modified":"2026-08-18T03:56:46.332127212Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"7.1.5"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/686c2434f9f16b87aeed18d76cc562df9f2695ab"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6e4c62caecf792e8a15ad9bc7f371e57c17e3302"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74315.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74315"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:46.332127212Z"}}