From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 32AF7217F27 for ; Mon, 6 Apr 2026 07:38:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775461118; cv=none; b=XChB+KmT7Pwi9J0I94oukBa+IIxEZRznbYJGL1x3vbanAiyXs8J1QaxyBXfLCWcsVUnBAtLyTZeNrEZBhywrGVL1PVvNhWzsHNxI65TPE6gavZc9sipL5eVErPr68UvIeAhcIR6GL4oC3ta1c2O+gWr3RWOVEyOOEFfhMv/xTvw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775461118; c=relaxed/simple; bh=2E9wwLYi7xiTRPGXMDEK93BN2P0F7Gb4r5E8K1v3uV0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=h1z89eK8pCpVnLaq+Hc1lqAfjcXTN0FTgm0Y/Nx/mWRQq7O8vvh0IeYx8egcKyxqlO6DXQucdlwRtbJYRPFzCfScVFPMpHhrPVccz/fCYZLDGhSibNpViiVCML0AkHOQFtZlDpMDpVeC7BN+PpgUs0L7j8AslrQ1z79lhdJPOQs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ebChzg0T; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ebChzg0T" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F918C4CEF7; Mon, 6 Apr 2026 07:38:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775461117; bh=2E9wwLYi7xiTRPGXMDEK93BN2P0F7Gb4r5E8K1v3uV0=; h=From:To:Cc:Subject:Date:Reply-To:From; b=ebChzg0T6pSuMIoucIbTTg1J8SVR8lwHNkc1HOYE/pf4n54uKREM1ENIzBHl4EKiu UjvgKHfNt7zcjsBaX93M5RgOxNmCayDWIfW7+L8DHiK61JzVyB1jI9MfsVGhBCvBso SS0mZq5R6m3QRf6atfB3JXkJBOFVjHvpvahMkE64= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-31406: xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini() Date: Mon, 6 Apr 2026 09:38:29 +0200 Message-ID: <2026040628-CVE-2026-31406-e2f3@gregkh> X-Mailer: git-send-email 2.53.0 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=3407; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=VvB+zvlxx33o1a5pepTP2crLVeBgFQK6Tfz8+SlN3Ss=; b=owGbwMvMwCRo6H6F97bub03G02pJDJmXk75UXTQQ7SxOvf714x1/jvQVSb9kp+W7Pz74IOfdO dbi1yZLO2JZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAiW24wzHft3spTufjyI7Vj VWnyHVxpU0sq3jDMFf8ctuvhVO9NXrvYNnBOP1B8YefPewA= 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: xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini() After cancel_delayed_work_sync() is called from xfrm_nat_keepalive_net_fini(), xfrm_state_fini() flushes remaining states via __xfrm_state_delete(), which calls xfrm_nat_keepalive_state_updated() to re-schedule nat_keepalive_work. The following is a simple race scenario: cpu0 cpu1 cleanup_net() [Round 1] ops_undo_list() xfrm_net_exit() xfrm_nat_keepalive_net_fini() cancel_delayed_work_sync(nat_keepalive_work); xfrm_state_fini() xfrm_state_flush() xfrm_state_delete(x) __xfrm_state_delete(x) xfrm_nat_keepalive_state_updated(x) schedule_delayed_work(nat_keepalive_work); rcu_barrier(); net_complete_free(); net_passive_dec(net); llist_add(&net->defer_free_list, &defer_free_list); cleanup_net() [Round 2] rcu_barrier(); net_complete_free() kmem_cache_free(net_cachep, net); nat_keepalive_work() // on freed net To prevent this, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync(). The Linux kernel CVE team has assigned CVE-2026-31406 to this issue. Affected and fixed versions =========================== Issue introduced in 6.11 with commit f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae and fixed in 6.12.80 with commit 32d0f44c2f14d60fe8e920e69a28c11051543ec1 Issue introduced in 6.11 with commit f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae and fixed in 6.18.21 with commit 2255ed6adbc3100d2c4a83abd9d0396d04b87792 Issue introduced in 6.11 with commit f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae and fixed in 6.19.11 with commit 21f2fc49ca6faa393c31da33b8a4e6c41fc84c13 Issue introduced in 6.11 with commit f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae and fixed in 7.0-rc6 with commit daf8e3b253aa760ff9e96c7768a464bc1d6b3c90 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-2026-31406 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: net/xfrm/xfrm_nat_keepalive.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/32d0f44c2f14d60fe8e920e69a28c11051543ec1 https://git.kernel.org/stable/c/2255ed6adbc3100d2c4a83abd9d0396d04b87792 https://git.kernel.org/stable/c/21f2fc49ca6faa393c31da33b8a4e6c41fc84c13 https://git.kernel.org/stable/c/daf8e3b253aa760ff9e96c7768a464bc1d6b3c90