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 3EC8F3F6613 for ; Wed, 26 Aug 2026 14:40:54 +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=1787755259; cv=none; b=l4/lv60g2Fp8XxtK+2kdj5y2Ac3Fh+EtXCskZHP731RJ5gCaVhrrTx/5QtcnsIcIERHEdlFZV8CfD/oR6e9O7KVc/c5O4Wvu9OdZxQrAs4YHFmz4FJ+a3/oeY1SdRjMHx2Ey8BKJiPwe9GjKyTLc0nUvrh7sSqaR7cB6XVzuZ5o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787755259; c=relaxed/simple; bh=zymqcAGLcL6lLIZ0Bc/+a4YZQkWX7vdnOG2M1AjYCHs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=FanIoGfJvfaVsv+4Mxig3SgiWjRTBI6DXam7hy1idXrf2UwHeUAfve0FjgnzZwPB4dS484KQZ2I645I0+X7vSc2dvvWh0dN9r1gwI+54i7XrQ+pHLfHaRSuujWJNxQPlYSN9e+qRFNt9q3bs/NIytS9wDQ4wnd1WT8rrbCS2wRg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZXFrHsyL; 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="ZXFrHsyL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEC491F00A3D; Wed, 26 Aug 2026 14:40:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787755252; bh=Sk0Wo1RMznB3TzF2c21BlvZcbLiz6HtYdIWVQs3gnGE=; h=From:To:Cc:Subject:Date:Reply-To; b=ZXFrHsyLMEWlVQ0bGVAkmVW+gnzw0qYPvvrFkX4mctxPMTcweGKTSb2ccmnws/jA9 H9+MQy6Lwkd+ZgPRdZwFgGXzKcMSzryeIWjGG3tEqU15zEs30p3LTSMZmwy5fqBnNG 7Lu076n48zf4R/QW1iFGYjflE0iymkhXRIAiB69A= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-80536: xfs: bounds-check buffer log item's dirty bitmap Date: Wed, 26 Aug 2026 16:37:32 +0200 Message-ID: <2026082604-CVE-2026-80536-5666@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=3396; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=lU9grCL6J0/2PIRvACo3tZqha/ZGRGvbKCdxv++MVlc=; b=owGbwMvMwCRo6H6F97bub03G02pJDFl9vwR2LnE9pOJpMnfBtchZFeo8UveedRhkJV+Oefb30 iOtbQJnOmJZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAim7kZ5mfNs3T7wfh5efqT mjcNJ15nSdv87WNYcPT5mj1O71oPXA06/Zgt+NIRv0dTPgIA 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: xfs: bounds-check buffer log item's dirty bitmap xlog_recover_do_reg_buffer() replays each dirty region described by a buffer log item's bitmap into the buffer read for that item: memcpy(xfs_buf_offset(bp, (uint)bit << XFS_BLF_SHIFT), item->ri_buf[i].iov_base, nbits << XFS_BLF_SHIFT); The destination offset (bit/nbits, from the logged dirty bitmap) and the buffer size (from the logged blf_len) are both attacker-controlled and otherwise unrelated, yet the only thing bounding the copy is an ASSERT(), which compiles away on production kernels. A crafted image logging a small blf_len together with a bitmap bit past the end of that buffer drives the memcpy() past the buffer's allocation, corrupting adjacent kernel heap during mount-time log recovery. This is reachable by anyone who can get a crafted image mounted -- the malicious-filesystem threat model XFS already guards against elsewhere. Turn the ASSERT() into a real XFS_IS_CORRUPT() check that aborts recovery of the buffer with -EFSCORRUPTED, consistent with the validate-and-fail idiom already used in xlog_recover_do_inode_buffer() and xfs_dquot_item_recover.c. xlog_recover_do_reg_buffer() therefore becomes STATIC int and its three callers propagate the error. Found and confirmed with KASAN on a CONFIG_XFS_DEBUG=n build: the crafted image trips a slab-out-of-bounds write before this change and fails recovery cleanly with -EFSCORRUPTED after it. The Linux kernel CVE team has assigned CVE-2026-80536 to this issue. Affected and fixed versions =========================== Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 6.18.46 with commit f8288214459ead7e87d26e5822f62c14a4f2ed6b Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 7.1.10 with commit edaf5b6bd625356893da20d69a259b34a9de2694 Issue introduced in 2.6.12 with commit 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and fixed in 7.2 with commit 813f8136a2ce1fee266d02a7df73db6e8a541604 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-2026-80536 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: fs/xfs/xfs_buf_item_recover.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/f8288214459ead7e87d26e5822f62c14a4f2ed6b https://git.kernel.org/stable/c/edaf5b6bd625356893da20d69a259b34a9de2694 https://git.kernel.org/stable/c/813f8136a2ce1fee266d02a7df73db6e8a541604