From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4D30B58F07E for ; Fri, 11 Sep 2026 20:05:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789157154; cv=none; b=rjMf3sMhO0BqwefJm95JZzivZmUnjX+LP/Dp5x9u+DFJGC8BgldfrJHzRoiRsJNgmoFtt8u6FYFvnRJee01+eeGWnNbJj7JttTUY7pgrL6mhmX/04Bjxmyltgh6wjI5AFf3T9HiCqQmejJBgZKnPGebQP0VvRvc9OzgPBt4HmU8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789157154; c=relaxed/simple; bh=dQaBUj+k3Z10oxoSop2+JWyxiRNI1kyQk1vUFNGjAFQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Dt4MmUvcikoRLlsagZgTc84IdSwqmVEUG2+KhqRSRCbZD5LMn36wI+2dci0dUtEUYJW2T7MYaRWd0xe9I43HCCCs+G4A3axelE1oK4GlsA8+ct+kDxVXjA+r1VMcf2oBR8vFKc11lpTn0svHLOV6dee1WCrKOn72jMc4n4DV/Sc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=k97ZUcM2; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="k97ZUcM2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7ECE1F00899; Fri, 11 Sep 2026 20:05:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789157148; bh=HZLvK6Dnpt10hFZlN9HisKJ/PmCWkMIoGaI162uOuV8=; h=From:To:Cc:Subject:Date:Reply-To; b=k97ZUcM2q+0ohbq+0Sqn30l/+U31icGeErE6bjmE6w+CUnrvpiRDQQbVjzITDJ2Wv qgXNkTLmNpzRAyzsiW0ebwMLvAiVRcZ6JrUP7HV/OxUAOi00BZfJzYSXvyh4jph9vy Cr3gQ/95uWr0rR+Ff+FlqiNLdz2akcXgzkgwFB8Q= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89753: mm/vmscan: report RCU-tasks quiescent states in shrink_lruvec() Date: Fri, 11 Sep 2026 21:47:22 +0200 Message-ID: <2026091107-CVE-2026-89753-cf3b@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2814; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=1OeLs9P1ikRHQR7Z+PbuB0NOSjtVJRzwux6hMMALjNM=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIvvnqm1rXGSik7m/d34Yp2LX7C11Wll7uOed2bddc Ia5p8OBjlgWBkEmBlkxRZYv23iO7q84pOhlaHsaZg4rE8gQBi5OAZiIZDrDgsOOYssPTDO+cvzz 9OoTXuohd5ivZjDMU3Rk/3i47fAUtcmJHo8O2GsxZEmvBwA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman 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