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 7587A423761 for ; Thu, 3 Sep 2026 08:22:06 +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=1788423727; cv=none; b=AynIE9u3lCXiMG1MguRCwvr5oTZU3r0szDVfQ9qukcTgDLSn9lNAkLVq/ssZHLjzQDbenheg+eNBB5WfTwYlexrfvbmu/yy61Vi23jxcEKr8+c5uRwlGt3k8igE0dWpCVlYfX75F325hl5xJfyCoLoA5xK+bwK3URQhwmgP9b3w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788423727; c=relaxed/simple; bh=JanD3CPNDm22hley/WVSgZDGbOUPAz9Ba626Kzb7qCk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=F8BZakbtBLJltV2NPtNFx7I0eb0KAmkBCNSOv1SZe1mWxLl/fDBTO4h3h2O+5Qj9lH9xJANsbsgwCxuH5sTjQ1F1o3gNqzzevGKFvzqtk6j5/pdK99O+KQxws/jTEi2iS310YE9hAiOEtzwm6qTakGKeLAXnopThdDjeMXaTF4A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lgGlBQ2h; 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="lgGlBQ2h" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 729221F000E9; Thu, 3 Sep 2026 08:22:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788423726; bh=xLdm62cXCE7Q7KspWDw2Z56TbNCnIOXOMl77Z+wjrbY=; h=From:To:Cc:Subject:Date:Reply-To; b=lgGlBQ2hmOkgi3YqJa6gU918b3bqTZZM1SLsqmC+7nwyA46avKAIpODhBLb5K4zsp yUAJq9XB0WnzJtxzlZw5lGCh/+3qYVLy8xhUQmBkYaGneeesFnqbi7o8MdSkNeNWpl lubm0xKisvr0WvLVB5ARXjgi2kYiSygLgb/RVi7o= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-80727: x86/mce: Set up the polling timer before CMCI discovery Date: Thu, 3 Sep 2026 10:21:56 +0200 Message-ID: <2026090357-CVE-2026-80727-af1b@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=3417; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=C1GREAwYMjxA2lmN64Soo0aeVkRnuhBS8qRs85zOMQs=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkz9VQLNBiLBB7P2jopeZ1Kf4WP58lNpUxJtx8ItH1zq WCuO6jVEcvCIMjEICumyPJlG8/R/RWHFL0MbU/DzGFlAhnCwMUpABP5d5RhnsbRrbapnXMM/ZZF fLt2T+nPEU/VPQwLlh4WWt5z997j/jfGE5uvt7EdWbpmEQA= 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: x86/mce: Set up the polling timer before CMCI discovery I hit the following on one of my machines: mce: CPU0 BANK15 CMCI inherited storm ------------[ cut here ]------------ ODEBUG: assert_init not available (active state 0) object: (____ptrval____) object type: timer_list hint: 0x0 WARNING: lib/debugobjects.c:632 at debug_object_assert_init+0x178/0x230, CPU#0: swapper/0/0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 7.2.0-rc5 #3 PREEMPTLAZY RIP: 0010:debug_object_assert_init+0x18f/0x230 Call Trace: __mod_timer mce_timer_kick cmci_discover intel_init_cmci mce_intel_feature_init mcheck_cpu_init identify_cpu identify_boot_cpu arch_cpu_finalize_init start_kernel A second splat follows right after, from timer_setup() finding that same timer already queued: ODEBUG: init active (active state 0) object: (____ptrval____) object type: timer_list hint: stub_timer+0x0/0x10 This is happening because CMCI storm detection is trying to modify the timer before latter was properly set up. Set up the timer first. __mcheck_cpu_setup_timer() only calls timer_setup(), and depends on neither the generic nor the vendor init. [ bp: Massage commit message. ] The Linux kernel CVE team has assigned CVE-2026-80727 to this issue. Affected and fixed versions =========================== Issue introduced in 6.8 with commit 1f68ce2a027250aeeb1756391110cdc4dc97c797 and fixed in 6.12.105 with commit 17ab68d0cf6a41bff61b1e13c6141d9e463736ae Issue introduced in 6.8 with commit 1f68ce2a027250aeeb1756391110cdc4dc97c797 and fixed in 6.18.45 with commit e708fc1566ebd4a2d3f2546e6310d64d362db80d Issue introduced in 6.8 with commit 1f68ce2a027250aeeb1756391110cdc4dc97c797 and fixed in 7.1.9 with commit 4f4cba3947d2f0eceb32727e198ca2c149a653a9 Issue introduced in 6.8 with commit 1f68ce2a027250aeeb1756391110cdc4dc97c797 and fixed in 7.2 with commit a213dfaa2596c1c0dc4dae91c14fbfa499c03223 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-2026-80727 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: arch/x86/kernel/cpu/mce/core.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/17ab68d0cf6a41bff61b1e13c6141d9e463736ae https://git.kernel.org/stable/c/e708fc1566ebd4a2d3f2546e6310d64d362db80d https://git.kernel.org/stable/c/4f4cba3947d2f0eceb32727e198ca2c149a653a9 https://git.kernel.org/stable/c/a213dfaa2596c1c0dc4dae91c14fbfa499c03223