From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-72218: lockd: Plug nlm_file refcount leak on cached nlm_do_fopen() failure
Date: Sat, 15 Aug 2026 15:04:57 +0900 [thread overview]
Message-ID: <2026081547-CVE-2026-72218-9e91@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
lockd: Plug nlm_file refcount leak on cached nlm_do_fopen() failure
The cached-file path in nlm_lookup_file() reaches the found: label
unconditionally, even when nlm_do_fopen() fails. At that label
*result and file->f_count are updated before the error is returned.
The wrappers nlm3svc_lookup_file() and nlm4svc_lookup_file() then
bail out of their switch without copying *result back to their
caller, so the proc handler's local nlm_file pointer remains NULL
and the cleanup path skips nlm_release_file(). The f_count
increment is never released, and nlm_traverse_files() can no
longer reap the file because its refcount never returns to zero
between requests.
Short-circuit the cached path so neither *result nor f_count is
touched when nlm_do_fopen() fails on a hashed nlm_file.
The Linux kernel CVE team has assigned CVE-2026-72218 to this issue.
Affected and fixed versions
===========================
Issue introduced in 5.10.220 with commit e580323ac0b51ad10ec2e181d1f777479b7983e7 and fixed in 5.10.261 with commit 6cd84cefd8b73e85b9eda17b319bd40a670f3a38
Issue introduced in 5.15 with commit 7f024fcd5c97dc70bb9121c80407cf3cf9be7159 and fixed in 5.15.212 with commit fe3b45b56b6c3d4b6b341de27fa291005287a21c
Issue introduced in 5.15 with commit 7f024fcd5c97dc70bb9121c80407cf3cf9be7159 and fixed in 6.1.178 with commit cb3420c047957e565101585bb4f15e1a6e3de6b0
Issue introduced in 5.15 with commit 7f024fcd5c97dc70bb9121c80407cf3cf9be7159 and fixed in 6.6.145 with commit 7ce4c23e783e766507b2cef27bbf97e9ca944f1a
Issue introduced in 5.15 with commit 7f024fcd5c97dc70bb9121c80407cf3cf9be7159 and fixed in 6.12.97 with commit 84008bf1860e0ef8059a7583a1163f36b704d08a
Issue introduced in 5.15 with commit 7f024fcd5c97dc70bb9121c80407cf3cf9be7159 and fixed in 6.18.40 with commit 46d59ff421824b6483549d87f14efffbbbd1f6cb
Issue introduced in 5.15 with commit 7f024fcd5c97dc70bb9121c80407cf3cf9be7159 and fixed in 7.1.5 with commit 3a5c55a19cad62f2973be25fe96a1a9e7f618e8a
Issue introduced in 5.15 with commit 7f024fcd5c97dc70bb9121c80407cf3cf9be7159 and fixed in 7.2-rc1 with commit 70a38f87bed7f0694fd07988b47b2db1e10d8df3
Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.
Unaffected versions might change over time as fixes are backported to
older supported kernel versions. The official CVE entry at
https://cve.org/CVERecord/?id=CVE-2026-72218
will be updated if fixes are backported, please check that for the most
up to date information about this issue.
Affected files
==============
The file(s) affected by this issue are:
fs/lockd/svcsubs.c
Mitigation
==========
The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes. Individual
changes are never tested alone, but rather are part of a larger kernel
release. Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all. If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
https://git.kernel.org/stable/c/6cd84cefd8b73e85b9eda17b319bd40a670f3a38
https://git.kernel.org/stable/c/fe3b45b56b6c3d4b6b341de27fa291005287a21c
https://git.kernel.org/stable/c/cb3420c047957e565101585bb4f15e1a6e3de6b0
https://git.kernel.org/stable/c/7ce4c23e783e766507b2cef27bbf97e9ca944f1a
https://git.kernel.org/stable/c/84008bf1860e0ef8059a7583a1163f36b704d08a
https://git.kernel.org/stable/c/46d59ff421824b6483549d87f14efffbbbd1f6cb
https://git.kernel.org/stable/c/3a5c55a19cad62f2973be25fe96a1a9e7f618e8a
https://git.kernel.org/stable/c/70a38f87bed7f0694fd07988b47b2db1e10d8df3
reply other threads:[~2026-08-15 6:17 UTC|newest]
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