From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-89749: tracing: Fix crash passing ERR_PTR to kthread_stop()
Date: Fri, 11 Sep 2026 21:47:18 +0200 [thread overview]
Message-ID: <2026091106-CVE-2026-89749-7161@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix crash passing ERR_PTR to kthread_stop()
event_test_stuff() calls kthread_run() and unconditionally passes the
returned task_struct pointer to kthread_stop(). kthread_run() returns an
error pointer such as ERR_PTR(-ENOMEM) when kthread creation fails, for
example under memory pressure during the boot-time event self-test.
kthread_stop() then dereferences the invalid pointer, crashing the kernel.
Check the result of kthread_run() before passing it to kthread_stop(). Use
WARN_ON() so that a failure to create the self-test thread does not go
unnoticed, matching the ring-buffer self-test fix in commit
91542863abad ("ring-buffer: Fix crash passing ERR_PTR to kthread_stop()").
The Linux kernel CVE team has assigned CVE-2026-89749 to this issue.
Affected and fixed versions
===========================
Issue introduced in 2.6.31 with commit e6187007d6c365b551c69ea3df46f06fd1c8bd19 and fixed in 6.12.109 with commit 12a499f741fc5be3731c8b0a0d909406575cc2eb
Issue introduced in 2.6.31 with commit e6187007d6c365b551c69ea3df46f06fd1c8bd19 and fixed in 6.18.50 with commit adadf4192f700bca82abfda9fa6d58c0bf37cc04
Issue introduced in 2.6.31 with commit e6187007d6c365b551c69ea3df46f06fd1c8bd19 and fixed in 7.2.4 with commit c40e0b4fa365969e67011529eabdfb66d1022256
Issue introduced in 2.6.31 with commit e6187007d6c365b551c69ea3df46f06fd1c8bd19 and fixed in 7.3-rc1 with commit 649bc7df3e5d7be6f7996a95084037dbf3cad1e5
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-2026-89749
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/trace/trace_events.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/12a499f741fc5be3731c8b0a0d909406575cc2eb
https://git.kernel.org/stable/c/adadf4192f700bca82abfda9fa6d58c0bf37cc04
https://git.kernel.org/stable/c/c40e0b4fa365969e67011529eabdfb66d1022256
https://git.kernel.org/stable/c/649bc7df3e5d7be6f7996a95084037dbf3cad1e5
reply other threads:[~2026-09-11 20:05 UTC|newest]
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