{"id":"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-\u003efh.len bytes\ninto lock-\u003efh.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.","modified":"2026-08-18T03:56:46.332127212Z","published":"2026-08-15T05:58:13.504Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74315.json"},"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3de744ee4e4557da0d63be8a97ad44b4dad58912"},{"fixed":"686c2434f9f16b87aeed18d76cc562df9f2695ab"},{"fixed":"6e4c62caecf792e8a15ad9bc7f371e57c17e3302"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74315.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.1.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74315.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}