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 DEEB93D1715 for ; Fri, 28 Aug 2026 06:50:34 +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=1787899836; cv=none; b=hAZCq+HCyuLGqTYDA+b4BzmZW3sSrPI2fOg1aVm0bQ/HHZv2Vwb/dGFvf8T1Whu/iw8AcZZ9YbaJI3XnqgWzmOMpxwDkkMZhKDi1QacLT4IF3/XSj5cXwLdvvPxw1JUPlumNfTujWnQLR9bXrjZLb0TGd3PqR0IjT/LLVBi/qiA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787899836; c=relaxed/simple; bh=Qyd+8D7RfWvjvuA9fJntbaKzNf6wKYSORz9+/cp+qcI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=pMrYPnPMz7jbo8vwkgM/9VAjjGFbso6VwuR8JfdMZ2qP+J6x0ofH8cV1VKutRrg9vL7701jYRo7esktUVMK2iN2Gt6vreeHzx9ZrmVTVWBkN2U8+t4e1HkuRbmbhi/DeWAVVr0wG/TxwrbyeTOVXQbCIve1e6zlwut9cHRoRDQc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=q0OoqDuA; 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="q0OoqDuA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F12FF1F000E9; Fri, 28 Aug 2026 06:50:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787899834; bh=TJPv5eR1W8xY2tp6MCwQWLOtBBTWz5Dx3HJESYT9Nrs=; h=From:To:Cc:Subject:Date:Reply-To; b=q0OoqDuAQbf4gtNiJdU4nGuikgT3T4zRat0Lq0t57NZ3s20Jkj1PaTOTYZ1TONHt5 UYVjxkoUbW3Xf84mSl26sjPKkAKflgT8iyGxoU2Q1KD+3GmJBhVRTHdX/TdJz9M9bP 50Y7/jXc2AP2MOP5Xr/7PhqNgAidbZOrjBeR9YN8= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-80633: iommufd: Take dma_resv lock before dma_buf_unpin() in release path Date: Fri, 28 Aug 2026 08:49:10 +0200 Message-ID: <2026082839-CVE-2026-80633-da07@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=2920; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=gJlxIKWSzU+/Vy2A/qOWb/0N0r3TF/Mp26jmyUzdI1o=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkT9d25fsdKr4uQ8ExNK9AqX7Znhu79lrdH3b3qz/5rP B5sZxjcEcvCIMjEICumyPJlG8/R/RWHFL0MbU/DzGFlAhnCwMUpABPZ1sEwT/Pkk4uzkriLA6cp bWmq/PbcxlngE8N8/6rgJOZag7v9whdMtgvNeqx/aK41AA== 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: iommufd: Take dma_resv lock before dma_buf_unpin() in release path dma_buf_unpin() requires the caller to hold the exporter's dma_resv lock: void dma_buf_unpin(struct dma_buf_attachment *attach) { ... dma_resv_assert_held(dmabuf->resv); ... } iopt_release_pages() calls dma_buf_unpin() without taking that lock, so every iommufd_ioas_destroy()/iommufd_ioas_unmap() that releases the last reference on a DMABUF-backed iopt_pages triggers a WARN. This was hit while running tools/testing/selftests/iommu/iommufd: WARNING: drivers/dma-buf/dma-buf.c:1137 at dma_buf_unpin+0x62/0x70 RIP: 0010:dma_buf_unpin+0x62/0x70 Call Trace: dma_buf_unpin+0x62/0x70 iopt_release_pages+0xe4/0x190 iopt_unmap_iova_range+0x1c7/0x290 iopt_unmap_all+0x1a/0x30 iommufd_ioas_destroy+0x1d/0x50 iommufd_fops_release+0x93/0x150 __fput+0xfc/0x2c0 __x64_sys_close+0x3d/0x80 do_syscall_64+0x65/0x180 Take the dma_resv lock around dma_buf_unpin() in iopt_release_pages(), matching the iopt_map_dmabuf() convention. dma_buf_detach() acquires the reservation lock internally, so it must remain outside the locked region. The Linux kernel CVE team has assigned CVE-2026-80633 to this issue. Affected and fixed versions =========================== Issue introduced in 7.1 with commit 8c5f9645c3893f0db679d9affe4fe4e665b990dd and fixed in 7.1.5 with commit cc69d0332421fd2943b66dbe5e597bf4fd5af126 Issue introduced in 7.1 with commit 8c5f9645c3893f0db679d9affe4fe4e665b990dd and fixed in 7.2 with commit e745cd2c749e557c14a15ac931761c3f58c24489 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-2026-80633 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/iommu/iommufd/pages.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/cc69d0332421fd2943b66dbe5e597bf4fd5af126 https://git.kernel.org/stable/c/e745cd2c749e557c14a15ac931761c3f58c24489