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 9CD9413A258 for ; Sun, 19 Jul 2026 15:46:11 +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=1784475972; cv=none; b=Ex6nzUk/ewLUpL1YjL5RV68gwkyJmt5N9bo4DF00SrCdaIwuyLFfI3NNnzJsh7LxSp+TbxPz+4KkgnNSLQG2WQdw8UYiZXykhmN7Uud3kRzVJVdRwcHZN9gVKQKcmTo4jHxd1uMFaTmVJ3zIfQyGvuVAzx+kQQ/mNCRbtEFQk1k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784475972; c=relaxed/simple; bh=rIqk8wm1Y8YC+sFldsTEQVhuByEUIii8KGUOJDPK0YU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Byci4VDNczy22epnk7L1UmNrxhlPYeuxm/byyAOyOUP3EzHYv97bd+SnjtbZGU3EvpaQaDpn3dUqpwBvQ6nrLNVgGqfEyXu4v1p3RXYx0ezPBrXvmCSBL74kf0gp4MKuuVWecw33hxmgwzEoqG8kRuvkHJrTYJ1djtuVVHARNY8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VoNRJUtK; 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="VoNRJUtK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D7BC1F000E9; Sun, 19 Jul 2026 15:46:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784475971; bh=ZEHeo/Gmc2TXrgBnz4cHNUh4p3yPi1OwG8f4SX3CDXg=; h=From:To:Cc:Subject:Date:Reply-To; b=VoNRJUtKAE4FJAIQ34dtJ4zSxtiEQdG5GF1HcxvdbwpPFr0k3Bvq8ljucIHd5qsff oNVun0E4VO3sXsUMleIaA72udbXWOhQSYXANnCfISib9A8w/VhAWKtOK/P2JcvLH6n QspBneiLou0EfluauMFRqchVcNVtqQLe0kLYZTgs= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-64149: dma-mapping: move dma_map_resource() sanity check into debug code Date: Sun, 19 Jul 2026 17:40:11 +0200 Message-ID: <2026071931-CVE-2026-64149-7a2b@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=3460; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=KkWfnpVAStKt68PG9HWVoRUDKmdJyPxom746pzq+Nao=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkx78ub/N84Nk+58od9qdy7662VjIx3G4o95f7JTeuwV ywoEC7tiGVhEGRikBVTZPmyjefo/opDil6Gtqdh5rAygQxh4OIUgImormFYsEfOZjvbjurJYvuf S2ZVVaqdW7XEnWHBrs1/upPT9y9z771dK2o9IXPfyVlbAA== 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: dma-mapping: move dma_map_resource() sanity check into debug code dma_map_resource() uses pfn_valid() to ensure the range is not RAM. However, pfn_valid() only checks for availability of the memory map for a PFN but it does not ensure that the PFN is actually backed by RAM. On ARM64 with SPARSEMEM (128MB section granularity), MMIO addresses that share a section with RAM will falsely trigger the WARN_ON_ONCE and cause dma_map_resource() to return DMA_MAPPING_ERROR. This causes a WARNING on Raspberry Pi 4 during spi_bcm2835 probe because the SPI FIFO register (0xfe204004) falls in the same sparsemem section as the end of RAM (0xf8000000-0xfbffffff), both in section 31 (0xf8000000-0xffffffff). Move the sanity check from dma_map_resource() into debug_dma_map_phys() and replace the unreliable pfn_valid() with pfn_valid() && !PageReserved(), which correctly identifies actual usable RAM without false positives for MMIO regions that happen to have struct pages. Since dma_map_resource() is dma_map_phys(DMA_ATTR_MMIO), the check applies equally to both APIs. Any non-reserved page represents kernel memory to a sufficient degree that using DMA_ATTR_MMIO on it is almost certainly wrong and risks breaking coherency on non-coherent platforms. ZONE_DEVICE pages used for PCI P2P DMA (MEMORY_DEVICE_PCI_P2PDMA) have PageReserved set, so they will not trigger a false positive. The check no longer blocks the mapping and uses err_printk() to integrate with dma-debug filtering. The Linux kernel CVE team has assigned CVE-2026-64149 to this issue. Affected and fixed versions =========================== Issue introduced in 6.18 with commit f7326196a781622b33bfbdabb00f5e72b5fb5679 and fixed in 6.18.34 with commit 181e67bc11c5ec5b87c6c512c2078752b23ca8d4 Issue introduced in 6.18 with commit f7326196a781622b33bfbdabb00f5e72b5fb5679 and fixed in 7.0.11 with commit 004a777879ff629f6e0ca3d09ad09fa3452bcc4d Issue introduced in 6.18 with commit f7326196a781622b33bfbdabb00f5e72b5fb5679 and fixed in 7.1 with commit af0c3f05866237f7592219bfe05387bc3bfc99b5 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-2026-64149 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: kernel/dma/debug.c kernel/dma/mapping.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/181e67bc11c5ec5b87c6c512c2078752b23ca8d4 https://git.kernel.org/stable/c/004a777879ff629f6e0ca3d09ad09fa3452bcc4d https://git.kernel.org/stable/c/af0c3f05866237f7592219bfe05387bc3bfc99b5