From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-89753: mm/vmscan: report RCU-tasks quiescent states in shrink_lruvec()
Date: Fri, 11 Sep 2026 21:47:22 +0200 [thread overview]
Message-ID: <2026091107-CVE-2026-89753-cf3b@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
mm/vmscan: report RCU-tasks quiescent states in shrink_lruvec()
I am seeing some rcu_tasks stalls in the Meta fleet during reclaim.
INFO: rcu_tasks detected stalls on tasks:
0000000088620d09: .. nvcsw: 6735/6735 holdout: 1 idle_cpu: -1/8
task:GlobalCPUThread state:R running task pid:2552016 tgid:2524552
Call Trace:
shrink_lruvec
mem_cgroup_iter
shrink_node
do_try_to_free_pages
try_to_free_pages
__alloc_frozen_pages_noprof
alloc_pages_noprof
pte_alloc_one
__pte_alloc
handle_mm_fault
Nothing promises direct reclaim returns in bounded time, and the scan loop
in shrink_lruvec() only calls cond_resched(), which is a no-op on
PREEMPTION kernels. Involuntary preemption is not a Tasks-RCU quiescent
state, so the reclaiming task never reports one and becomes a holdout.
Upgrade it to cond_resched_tasks_rcu_qs(), which reports a quiescent state
even when cond_resched() does nothing.
PS: This has been discussed in [1]
The Linux kernel CVE team has assigned CVE-2026-89753 to this issue.
Affected and fixed versions
===========================
Fixed in 6.12.109 with commit b5391676c61d94ffe3272dcf6723738b802f79e8
Fixed in 6.18.50 with commit 3fd50239986302cb050d3649351bcec00fa9d5ab
Fixed in 7.2.4 with commit cf3ba0911a1cf8680371ff113b90088edd01d2bb
Fixed in 7.3-rc1 with commit 25f52e81216884a7444bf07a606691feb09a94e3
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-2026-89753
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:
mm/vmscan.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/b5391676c61d94ffe3272dcf6723738b802f79e8
https://git.kernel.org/stable/c/3fd50239986302cb050d3649351bcec00fa9d5ab
https://git.kernel.org/stable/c/cf3ba0911a1cf8680371ff113b90088edd01d2bb
https://git.kernel.org/stable/c/25f52e81216884a7444bf07a606691feb09a94e3
reply other threads:[~2026-09-11 20:05 UTC|newest]
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