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 EC73216F27F for ; Sat, 25 Jul 2026 08:51:08 +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=1784969470; cv=none; b=j5Bao+C26y7o2rLVaGv6xCb7tvpbZF26sJmM8P9zx1DCMMToSn16fysp7PyMnraQsPxVq8rKKX80xULXFav24HrS0DUvsDmPcDBH5oE2Q9r7nu5QcpZVtvFadUNsJXwVtu47eirOpVmdyWDYXGXizk9d4lojiLbzK4+Es+ITvHM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784969470; c=relaxed/simple; bh=3tWVLFkjIWnnY4XgXOY4nhG/EtA7CCuQ+IvdLU2Th4I=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=iGQ7MnWp3lt6BtNRsA4YFUq7TuqMnH85aO160Vnb1FYNde8f7Au71wLNiOJNDSF9F8fGDnFSDa+HIQNcctu8aSDmrjVchWW+80CkPdgVAqVQBHlvzEZ+BtCEL1OgJdY69/yu15NmBFJoh5k1ly+sELDMjH9uUXCA7RcFCRzx6q4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KbVaYVZe; 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="KbVaYVZe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A5631F000E9; Sat, 25 Jul 2026 08:51:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784969468; bh=4u3E9s6iVtiA6spIXgieEylNax01tKoQX/5RNaSTXIw=; h=From:To:Cc:Subject:Date:Reply-To; b=KbVaYVZehi6w3o2+lVGnvIGsbNL7qifKTiYUGATLd65HVqfukvu0GQFSXdtcA6e0Q gdLu5lgKOVT2upxDGqTnwM+cv7tE4oO6Xo9jEaybjqTKxg3qMIjL5UT9vvT2eQ3CVs pkZGKlRjGnppYSbR9hcF14vmTrA+DA15Wcz0OBdE= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-64267: fuse: avoid 32-bit prune notification count wrap Date: Sat, 25 Jul 2026 10:48:04 +0200 Message-ID: <2026072559-CVE-2026-64267-a265@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=2665; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=4s0JUYvZM1Cjet7ijn6CazTv1erT2X0hsLIBs5XM3Ak=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkpFfbHRHsdXNwD/t3JWfRzee/3eXkvct9tzVdOedCzU nBuVo9uRywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEwkXY9hwczd9budQk39my6+ M50Zv2fd9LmHXzIs2OKQm/DTQ+Du6btTGHZMWFbncOLHQwA= 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: fuse: avoid 32-bit prune notification count wrap FUSE_NOTIFY_PRUNE validates the nodeid payload length with: size - sizeof(outarg) != outarg.count * sizeof(u64) On 32-bit kernels, size_t is also 32 bits, so the daemon-controlled count multiplication can wrap. A prune notification with count 0x20000000 and no nodeid payload passes the check, enters the copy loop, and asks the device copy path to read nodeids that are not present in the userspace write buffer. In QEMU this reaches the fuse_copy_fill() BUG_ON(!err) path. Validate the payload length with array_size() instead. That accepts exactly the same valid messages, but avoids wrapping arithmetic before the copy loop consumes the count. The Linux kernel CVE team has assigned CVE-2026-64267 to this issue. Affected and fixed versions =========================== Issue introduced in 6.18 with commit 3f29d59e92a96d843c2ff10ebfed92ac26878658 and fixed in 6.18.39 with commit 6e2d84fdeac05bfd858e84a76353fdb84f23a43e Issue introduced in 6.18 with commit 3f29d59e92a96d843c2ff10ebfed92ac26878658 and fixed in 7.1.4 with commit c78c4b242299bc581e4987e5c2786c6f4760c516 Issue introduced in 6.18 with commit 3f29d59e92a96d843c2ff10ebfed92ac26878658 and fixed in 7.2-rc1 with commit 54243797cedf55447b4c5d560e8cd709900061ae 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-2026-64267 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/fuse/dev.c fs/fuse/notify.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/6e2d84fdeac05bfd858e84a76353fdb84f23a43e https://git.kernel.org/stable/c/c78c4b242299bc581e4987e5c2786c6f4760c516 https://git.kernel.org/stable/c/54243797cedf55447b4c5d560e8cd709900061ae