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 093365867C4 for ; Fri, 11 Sep 2026 19:56:39 +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=1789156602; cv=none; b=cCX1EUqdIo9/Z5GQEIaAjHItv9jqRMPcXK6N0WqRQr3HErx2k0mDccmn0FaYWcHrj53TwIoFy27tAbAQteULHNeFmId6Cg+45PNBShbBXWJraFddOq3DOOGGNuOXS59+yyq0BNgB4Atszp14VBtt2zRDEYUt1/SjMEXvsNCgqS8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156602; c=relaxed/simple; bh=GwdeDA99TQZTJHRVip20eRObQkiyhktkzIEVuoYIRkY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=eQXjRfn2BuMJIoocHVvr85XDdnP1NmiIJrK0PSbVy9n9WzdJLx3LYcGEfcomuwqQ//YPCjfUBqz/dOjdc2utYNRVYqTqcgvqyD6NCZNuaGcpsLuAwA2O8sFV0Q9PdJg1ziO+5B1elRkOlOl1r5f2++XwVj4b6xVOSHQk8stbU4A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dK91BQjB; 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="dK91BQjB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B50641F00899; Fri, 11 Sep 2026 19:56:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156598; bh=hCoLnE5o+p++KWghrFKSOgQaZZ90IG9NCTdyaUJ39a4=; h=From:To:Cc:Subject:Date:Reply-To; b=dK91BQjBj85XnPtQ8P7qUkiJCB7dp2NIv/4HJDLl9SYrmAkPXF1Mxa/zyBftd3t5a WWMQv8btUWzGTfJgSfL5VKOP+DwmiYxR82RTwDCvTjeA3EPv97x8Xp58/2YAubyUXp rJmAu6Dca/aJEpahK19RoNcQVU0yeubbsR4sYv9M= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89570: cxl/mce: Make the MCE notifier per-region Date: Fri, 11 Sep 2026 21:44:19 +0200 Message-ID: <2026091125-CVE-2026-89570-445f@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=2873; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=Te0XL8YPYZK0KV+L67D2hR97RFIRGTZepWf6RWRSrXo=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLItO0YrzD5B6Jr7FfsHPX93UNdes9uYvOBNs1pk+xX b3b+ezOjlgWBkEmBlkxRZYv23iO7q84pOhlaHsaZg4rE8gQBi5OAZjI78MMC65e7DI1fW/aqir1 R/o6+9Sf90wnhzDMd/lQrnWpvFDqcUTxQbm/OWdWNkhfBQA= 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: cxl/mce: Make the MCE notifier per-region Flavien Solt reported lifetime issues with the CXL MCE notifier, which can lead to NULL dereferences and use-after-free in the MCE handler. The notifier was registered per memory device and stored in 'struct cxl_memdev_state', even though it only needs the region state (the region's SPA range and its extended linear cache size). Instead of keeping the memory device and endpoint alive, the correct fix is to move the notifier into 'struct cxl_region' and register it from cxl_region_probe() as it should be a per-region notifier. Setup the registration to only happen for regions that have an extended linear cache as that is the only current usage. Remove cxl_port_get_spa_cache_alias() as it is now dead code. [ dj: Update dev_warn() when notifier fails due to kconfig. (Ben) ] The Linux kernel CVE team has assigned CVE-2026-89570 to this issue. Affected and fixed versions =========================== Issue introduced in 6.15 with commit 516e5bd0b6bf4ae1ad072df637b428a737c3c870 and fixed in 6.18.51 with commit 5563db13c9528a56c7161260ec75ec8690dc5608 Issue introduced in 6.15 with commit 516e5bd0b6bf4ae1ad072df637b428a737c3c870 and fixed in 7.2.4 with commit 491d8c9ac98d55073bda778f88a5248d4cce3fa0 Issue introduced in 6.15 with commit 516e5bd0b6bf4ae1ad072df637b428a737c3c870 and fixed in 7.3-rc1 with commit 775d0f4558f4cec0ee0c8966595d1add1791f36e 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-2026-89570 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: drivers/cxl/core/mbox.c drivers/cxl/core/mce.c drivers/cxl/core/region.c drivers/cxl/cxl.h drivers/cxl/cxlmem.h 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/5563db13c9528a56c7161260ec75ec8690dc5608 https://git.kernel.org/stable/c/491d8c9ac98d55073bda778f88a5248d4cce3fa0 https://git.kernel.org/stable/c/775d0f4558f4cec0ee0c8966595d1add1791f36e