CVE-2026-74315

In the Linux kernel, the following vulnerability has been resolved: lockd: Avoid hashing uninitialized bytes in nlm4svc_lookup_file() file_hash() digests the first LOCKD_FH_HASH_SIZE bytes of nfs_fh.data when bucketing nlm_files[], independent of fh.size. Commit 3de744ee4e45 ("lockd: Use xdrgen XDR functions for the NLMv4 TEST procedure") set .pc_argzero to zero for the converted procedures and moved file-handle population into nlm4svc_lookup_file(), which copies only xdr_lock->fh.len bytes into lock->fh.data. When an NLMv4 client presents a file handle shorter than LOCKD_FH_HASH_SIZE, bytes fh.len..31 retain whatever the argument buffer held from an earlier request. The same wire handle then hashes to different buckets across calls; nlm_lookup_file() misses the existing nlm_file entry, and lock-state lookups fail. Zero only the tail bytes that file_hash() would otherwise consume. Handles of LOCKD_FH_HASH_SIZE or larger already populate every byte that file_hash() reads.

Affected products

Kernel, Linux, Linux-Allwinner-5.19, Linux-Aws-5.0, Linux-Aws-5.11, Linux-Aws-5.13, Linux-Aws-5.19, Linux-Aws-5.3

CVSS 3.1

9.8 CRITICAL

EPSS

0.4% (31th percentile)

NVD status

Received

Published

2026-08-15

No exploit for CVE-2026-74315 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.