Skip to content
CVE PROGRAM SOURCE RECORD7.1 High

CVE-2026-89691

nfsd: clear opcnt on compound arg release to prevent OOB read

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: clear opcnt on compound arg release to prevent OOB read nfsd4_release_compoundargs() resets args->ops to the inline iops[8] array when the dynamically-allocated ops buffer is freed, but leaves args->opcnt at its original value (which can be up to 200 for NFSv4.1+ compounds). If rq_status_counter is stuck at an odd value (which can happen when nfsd_dispatch() hits an error path after setting it odd), the RPC status dumpit handler reads min(opcnt, 16) entries from args->ops[]. Since iops only has 8 elements and is the last field in struct nfsd4_compoundargs, reading indices 8-15 accesses adjacent slab memory and leaks it to userspace via netlink. Zero opcnt unconditionally in nfsd4_release_compoundargs() so stale compound metadata is never exposed through the status interface. [ cel: Remove the kvfree_rcu_mightsleep() sleep from the exposure window ]

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • bd9d6a3efa9709e653aafbeb859289feccb8e70c to < 58bcdfb2b2e412088839ae740b1a95154dc0b8d0affected
  • bd9d6a3efa9709e653aafbeb859289feccb8e70c to < e879148867bd4c4cac42e063ffaffa187dddc6feaffected
  • bd9d6a3efa9709e653aafbeb859289feccb8e70c to < c1a4f7b1848f95302df598217e1c7a1410c2d0c5affected
  • bd9d6a3efa9709e653aafbeb859289feccb8e70c to < ae4c38555e81563b8dc5eae55ffd70f0ea97aa5aaffected

Linux Linux

Default version status: affected

  • 6.7affected
  • 0 to < 6.7unaffected
  • 6.12.109 to ≤ 6.12.*unaffected
  • 6.18.50 to ≤ 6.18.*unaffected
  • 7.2.4 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References