From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-89643: audit: avoid dropping live tree ref on fsnotify rule autoremove
Date: Fri, 11 Sep 2026 21:45:32 +0200 [thread overview]
Message-ID: <2026091142-CVE-2026-89643-d95f@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
audit: avoid dropping live tree ref on fsnotify rule autoremove
audit_del_rule() is used for both netlink deletion templates and internal
fsnotify autoremove. The former passes a parsed template which owns a
temporary tree reference; the latter passes the installed entry itself.
The unconditional audit_put_tree() at the end of audit_del_rule() assumes
the template case. For mixed AUDIT_DIR plus AUDIT_EXE rules, an fsnotify
autoremove event therefore drops the installed rule's live tree reference.
Repeating this across rules sharing the same tree can free the tree while
another rule still references it, and a later autoremove dereferences the
freed pathname while comparing rules.
Move the temporary-tree put to audit_rule_change(), the caller that owns
deletion templates. Keep it in the AUDIT_DEL_RULE cleanup so both
successful deletion and -ENOENT still release the parser-owned tree.
[PM: dropped unnecessary comment for line length reasons]
The Linux kernel CVE team has assigned CVE-2026-89643 to this issue.
Affected and fixed versions
===========================
Issue introduced in 4.3 with commit 34d99af52ad40bd498ba66970579a5bc1fb1a3bc and fixed in 6.12.109 with commit cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28
Issue introduced in 4.3 with commit 34d99af52ad40bd498ba66970579a5bc1fb1a3bc and fixed in 6.18.50 with commit 636a99bab36ba27515363d325866c0273ac83b3e
Issue introduced in 4.3 with commit 34d99af52ad40bd498ba66970579a5bc1fb1a3bc and fixed in 7.2.4 with commit 583cf579b32d99e3fe4e9c8ecc4d852e3708fbec
Issue introduced in 4.3 with commit 34d99af52ad40bd498ba66970579a5bc1fb1a3bc and fixed in 7.3-rc1 with commit 783f0f0974c156aca630f4ffff248671082a098d
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-2026-89643
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:
kernel/auditfilter.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/cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28
https://git.kernel.org/stable/c/636a99bab36ba27515363d325866c0273ac83b3e
https://git.kernel.org/stable/c/583cf579b32d99e3fe4e9c8ecc4d852e3708fbec
https://git.kernel.org/stable/c/783f0f0974c156aca630f4ffff248671082a098d
reply other threads:[~2026-09-11 20:00 UTC|newest]
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