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 7E4273EA957 for ; Sat, 15 Aug 2026 12:28:42 +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=1786796923; cv=none; b=RXemGBwPAvQiq+vZZ8Hy5ShB2Hao91UNjVhlolfcmzvCUSUEwUD+9Gr3y65ouyjzSrdJEqrNnbsOFNLfoplAZJDn9uErCLZvvbDX2kIryJSd6kocA97Gpw/hslZ5Deot+SulgJwVXYQd8Kg6OTUquZIjv8787SyQwgcKCo7CXmM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786796923; c=relaxed/simple; bh=JEPCer9+XHZgm5qS27vD4gUeLsqOBaezZzeIS9v93BA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=U0E8a3Kq4GhgWaQ6DV29hHjatgvkLKx9QBUug16h0v5cIHeA++DvX54Ma/PRm8axpgx4dNqHu4Cn4fAzU98BCK7hpeNI+lt0yezpB2c9ibzbqbMZUALIXE3L/Lb6qZWLOstCkCgRQ6DG0jFSzN9NLVBRVM+V5u/NxSvar/H6HXo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=IaydD9U8; 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="IaydD9U8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 968F81F000E9; Sat, 15 Aug 2026 12:28:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786796922; bh=oH7dysAkO4Ap0EzJ5gtsn/TVhXo+7IzwqjaqxRPBq7c=; h=From:To:Cc:Subject:Date:Reply-To; b=IaydD9U86rvBbWJBAICqnYGLkhsMyf7HQKkqb6twk8COC3C10EdlQM0HJZeufmyOr 5VTn28p331ySHHXqa/dlkCVjJ8WrNzczvFyOh6nf4EazmHkVEwgmjQ3/RO/ocUyGny 8yhcdzxTfDVKXIChtqZ5gegQ2XFK9UwF5xKQ7GPs= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-74440: drm/xe: Wait on external BO kernel fences in exec IOCTL Date: Sat, 15 Aug 2026 21:25:21 +0900 Message-ID: <2026081526-CVE-2026-74440-bfa3@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=3524; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=6f0vljUUZUylz7HgbD1qEorTO7rGp3QexK42irQJ2vc=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkNUdv2KgWJaU4X2W8+84/0iztXRVa2Tf8WYXT3BduxP 2rmyvkdHbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjCRp08Y5und4tI5nLQyZye7 8fW3IgtzeOJdHzEsaF2WfHXWmWyjK52Hddu5F2XVOX4uAQA= 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: drm/xe: Wait on external BO kernel fences in exec IOCTL Before arming a user job, xe_exec_ioctl() only added the VM's dma-resv KERNEL slot as a dependency. That slot covers rebinds and the kernel operations of the VM's private BOs, but not external BOs (bo->vm == NULL), which carry their kernel operations (evictions, moves, ...) in their own dma-resv KERNEL slot. The DMA_RESV_USAGE_KERNEL slot is the cross-driver contract for memory management operations that must complete before the BO or its backing store may be used: any accessor is required to wait on the KERNEL fences before touching the resv. By skipping the external BOs' KERNEL slots, the exec path violated that contract and could schedule a user job while a kernel operation on an external BO mapped by the VM was still in flight, racing against it and potentially reading or writing memory that was being moved. Replace the VM-only dependency with an iteration over every object locked by the exec, adding each object's KERNEL slot as a job dependency. This covers the VM resv (rebinds and private BOs) as well as every external BO, mirroring the drm_gpuvm_resv_add_fence() call that later publishes the job fence to the same set of objects. Long-running mode continues to skip this, as before. (cherry picked from commit a6b842acf3ddd1efc53a56de9260cfa718fb35e7) The Linux kernel CVE team has assigned CVE-2026-74440 to this issue. Affected and fixed versions =========================== Issue introduced in 6.8 with commit dd08ebf6c3525a7ea2186e636df064ea47281987 and fixed in 6.12.103 with commit 1738db550334adca0e7fcf0ef684198fb7462779 Issue introduced in 6.8 with commit dd08ebf6c3525a7ea2186e636df064ea47281987 and fixed in 6.18.44 with commit 21976fe5258494ac38b63d103be81bf1180ae4ae Issue introduced in 6.8 with commit dd08ebf6c3525a7ea2186e636df064ea47281987 and fixed in 7.1.8 with commit 5d363d00bc9799b90a0dc89eb1c5dcb909c042ee Issue introduced in 6.8 with commit dd08ebf6c3525a7ea2186e636df064ea47281987 and fixed in 7.2-rc3 with commit af80e2bfde9312c76b60cf9274248dce0410b30d 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-2026-74440 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/gpu/drm/xe/xe_exec.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/1738db550334adca0e7fcf0ef684198fb7462779 https://git.kernel.org/stable/c/21976fe5258494ac38b63d103be81bf1180ae4ae https://git.kernel.org/stable/c/5d363d00bc9799b90a0dc89eb1c5dcb909c042ee https://git.kernel.org/stable/c/af80e2bfde9312c76b60cf9274248dce0410b30d