CVE-2026-93231: Linux kernel · lockd: fix swapped arguments in nlmsvc_match_ip()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in d34c2ac447fe0490ede828e0143e2cbcb59e6c77 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:18 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in d34c2ac447fe0490ede828e0143e2cbcb59e6c77, b9060689f49dc663e9a3d069c4a65ff63a836e66, 21bcb609e0ab1dd60f39ca3498f85808933bcc9f +2
Exploitation evidence
Disclosed: evidence found.
CVE published 24 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: lockd: fix swapped arguments in nlmsvc_match_ip() When releasing locks by server IP address via /proc/fs/nfsd/unlock_ip, nlmsvc_unlock_all_by_ip() calls nlm_traverse_files() with the server sockaddr as the opaque @data argument: nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL); The match callback is later invoked from nlm_traverse_locks() as: match(lockhost, host); where the first argument is the nlm_host that owns the lock, and the second argument is the @data that was originally passed down (here the server sockaddr). This is the convention every other match callback relies on (nlmsvc_mark_host(), nlmsvc_same_host(), nlmsvc_is_client()): arg1 is the real nlm_host, arg2 is the caller-supplied reference value. nlmsvc_match_ip() has had these two arguments reversed ever since the unlock-by-IP feature was introduced in commit 4373ea84c84d ("lockd: unlock lockd locks associated with a given server ip"): return rpc_cmp_addr(nlm_srcaddr(host), datap); Here @host is actually the server sockaddr, so nlm_srcaddr(host) dereferences a struct sockaddr as a struct nlm_host and reads garbage at the offset of h_srcaddr; meanwhile @datap is actually the lock owner's nlm_host but is compared as a sockaddr. As a result the comparison practically never matches and locks are not released for the requested IP. Swap the arguments so the lock owner's source address is compared against the requested server address: return rpc_cmp_addr(nlm_srcaddr(datap), (struct sockaddr *)host); [ cel: fix the misleading typedef parameter names too ]
References
- git.kernel.org/stable/c/4fe2db296c9cd897dd1fe06cc0ae9cbc13beefc5 (opens in a new tab)
- git.kernel.org/stable/c/d34c2ac447fe0490ede828e0143e2cbcb59e6c77 (opens in a new tab)
- git.kernel.org/stable/c/0d72e78c9d38d5377a059a4837f82b65b91cdcf6 (opens in a new tab)
- git.kernel.org/stable/c/21bcb609e0ab1dd60f39ca3498f85808933bcc9f (opens in a new tab)
- git.kernel.org/stable/c/b9060689f49dc663e9a3d069c4a65ff63a836e66 (opens in a new tab)