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 3F62D18E025 for ; Sun, 19 Jul 2026 15:45:17 +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=1784475918; cv=none; b=aZYU786giQPMl3e/IYaCAT1aAYlGk7ItVqxHqXqBjBj9fCC72uYuxeiMLcCZR8Wy4ceBITpAPtMIAovzv9dGoDyI59COv3PAoEq/GP5coEEmwqSNx9aQOzrMoF2aH1j+hnIVnP6WR2gZJRki6azCmv3aWXFPfHPFHqhbcIE3+CA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784475918; c=relaxed/simple; bh=ouLkTjcHQV2GkEOLwNkfFL9XV4z8f4jk/cNk8ErO/VQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=DH284zP2lq9kJ/5i3zILjrnB5q3Qp0eW8zKnjz/1li9Ur6vTzwJj7G6TrU4vR3m9qETpfE0gh9R3kbn6gnH5oqnsX+H74WwLGGySt8O4kMhQlxq5AUTUyqtr/uhezlZkisLuPC7KN+HhrPSBOEKeuRknimvC6v8sXGk3ZCiasYU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CQ2sMfGS; 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="CQ2sMfGS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A28A91F000E9; Sun, 19 Jul 2026 15:45:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784475917; bh=EUQAPUNI11BRWvSy1pwmXBVa8AdMb3lE3Zpy86ftPGc=; h=From:To:Cc:Subject:Date:Reply-To; b=CQ2sMfGS1pFjEEmJtQlkvbAFCQJx8KYhYjgmGK/P2kvxQRqpTuuosnxZJaVPkB/tN i3NXizlTers1l5SCd/nxu/UHUh4vIxVWB3LT5vFmGQQR3+6fnhllmHC12C3CVWWCta exUnokdp+FgLkuyLNIigUsae8ThAajYZP0FnSlGU= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-64124: net: devmem: reject dma-buf bind with non-page-aligned size or SG length Date: Sun, 19 Jul 2026 17:39:46 +0200 Message-ID: <2026071925-CVE-2026-64124-0de6@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=2924; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=qXcxzaIPJcXU1brcQl6iBXf6dzS9XAu0v9Cgkcr7+Wk=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkx7wvttJgCbx5n6WdqmFFxupL/mtO3N92+DZ0Ls8LOR /qJSZ/uiGVhEGRikBVTZPmyjefo/opDil6Gtqdh5rAygQxh4OIUgImscWZYMHO6UJxAU0akyD+B mKiI1KMM/y8yMSyYU5eQLlfN/+rnzUh2Cf9osZK7YVwA 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: net: devmem: reject dma-buf bind with non-page-aligned size or SG length net_devmem_bind_dmabuf() trusts dmabuf->size and sg_dma_len() to be PAGE_SIZE multiples without checking: - tx_vec is sized dmabuf->size / PAGE_SIZE, and net_devmem_get_niov_at() only bounds-checks virt_addr < dmabuf->size before indexing tx_vec[virt_addr / PAGE_SIZE]. With size = N*PAGE_SIZE + r (1 <= r < PAGE_SIZE), sendmsg() at iov_base = N*PAGE_SIZE passes the bound check and reads tx_vec[N] -- one past. - owner->area.num_niovs = len / PAGE_SIZE while gen_pool_add_owner() covers the full byte len, so a non-page-multiple non-final sg desyncs num_niovs from the gen_pool region for every later sg, on both RX and TX. dma-buf does not require page-aligned sizes, so the bind path has to enforce what its own indexing assumes. Reject both with -EINVAL. The size check is TX-only (only tx_vec is sized off dmabuf->size); the SG-length check covers both directions. The Linux kernel CVE team has assigned CVE-2026-64124 to this issue. Affected and fixed versions =========================== Issue introduced in 6.16 with commit bd61848900bff597764238f3a8ec67c815cd316e and fixed in 6.18.35 with commit 134c517dfa63203287b2aad6558017f42435a02e Issue introduced in 6.16 with commit bd61848900bff597764238f3a8ec67c815cd316e and fixed in 7.0.11 with commit d5008e4e4ee6b739256b796702a7d1aae1b5c3b4 Issue introduced in 6.16 with commit bd61848900bff597764238f3a8ec67c815cd316e and fixed in 7.1 with commit 4eb82ba543421e9e38cc14e4e82058b78850df50 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-2026-64124 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/core/devmem.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/134c517dfa63203287b2aad6558017f42435a02e https://git.kernel.org/stable/c/d5008e4e4ee6b739256b796702a7d1aae1b5c3b4 https://git.kernel.org/stable/c/4eb82ba543421e9e38cc14e4e82058b78850df50