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 46B3B2741B5 for ; Mon, 8 Jun 2026 15:51:12 +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=1780933873; cv=none; b=iS0gFc44cPkUBQjvk2ENN6cdortGpwBh+672s4BmLtTYJIXqCj/oUgTeYDkKzyc6NcRtpLH+V1NWQqlI3FvGmvhuIKqOgztx61644eznpNRCx6RsE0/yHCzdqlLyi2Bcnz7iBQD7i5uaLiCR/pEv7O/CpmvfqVDs9zF1M1XeGOk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780933873; c=relaxed/simple; bh=QXntGJsqWYQQfBzgkTVuUFUbKRfCnrkbp/8BVsq/7nY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=UM0MAbELpfW+pSASBolwZJE45Gbn+HYpNpV7DJY/8Q8ZbnaAegKKdS4Q8tPp6a6nQ2HMOE4C3bmD37rnATwqebL5p7k8vXNqx9rGZqyTmHcVhzFBRXeUNzPwwJFe74l+GJYdR0i2FpX07eL6/zZA4tK99rFzlSAEa95WRrTcps8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dgYv4MHH; 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="dgYv4MHH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F7271F00893; Mon, 8 Jun 2026 15:51:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780933872; bh=yO/pZonodGhSw6PeGW82kAv4qZcs6N2tRr/znBEGMJs=; h=From:To:Cc:Subject:Date:Reply-To; b=dgYv4MHHlFMlwxrKWfvu7I1JtRjXQUO7LMvXjCMrPDtHEhWGYdVkEsLwcAhWHaBZr zWQtvTXNhCyTvdLK7xhX3YOvaneTAoLVUyjGLePxcGmsMsWULaxaksqIIS9sg7KbAR nJm3qira4TYHX88xzwMO5ZkTqYl9R5lVK9aReT7o= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-46314: drm/v3d: Reject empty multisync extension to prevent infinite loop Date: Mon, 8 Jun 2026 17:49:58 +0200 Message-ID: <2026060854-CVE-2026-46314-2b40@gregkh> X-Mailer: git-send-email 2.54.0 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=2986; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=+uup+2cMMRAwdbP7fjtcKpDuq1nKnds94L7B/24Jv6E=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlqTxY9EZ9tIcl/85Bs8/+YzLdv8z/zPOW6p3Mo9bNBT QvDDJHJHbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjCR+y8YFsxV+uthObHyuE1c M4+R+4vE+xdyzRjm8Pzb2fnjdQrT7R6Z0utmgVILtwe1AgA= 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/v3d: Reject empty multisync extension to prevent infinite loop v3d_get_extensions() walks a userspace-provided singly-linked list of ioctl extensions without any bound on the chain length. A local user can craft a self-referential extension (ext->next == &ext) with zero in_sync_count and out_sync_count, which bypasses the existing duplicate- extension guard: if (se->in_sync_count || se->out_sync_count) return -EINVAL; The guard never fires because v3d_get_multisync_post_deps() returns immediately when count is zero, leaving both fields at zero on every iteration. The result is an infinite loop in kernel context, blocking the calling thread and pegging a CPU core indefinitely. Fix this by rejecting a multisync extension where both in_sync_count and out_sync_count are zero in v3d_get_multisync_submit_deps(). An empty multisync carries no synchronization information and serves no useful purpose, so returning -EINVAL for such an extension is the correct defense against this attack vector. The Linux kernel CVE team has assigned CVE-2026-46314 to this issue. Affected and fixed versions =========================== Issue introduced in 5.16 with commit e4165ae8304e5ea822fbe5909dd3be5445c058b7 and fixed in 6.18.33 with commit 4fa42a249e8cd6ed17aea04e5695b6e9001f2433 Issue introduced in 5.16 with commit e4165ae8304e5ea822fbe5909dd3be5445c058b7 and fixed in 7.0.9 with commit 9c5164781cb388d219d8f49fa0f0b04cf86ad544 Issue introduced in 5.16 with commit e4165ae8304e5ea822fbe5909dd3be5445c058b7 and fixed in 7.1-rc1 with commit fb44d589bf3148e13452185a6e772a7efbf2d684 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-2026-46314 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/v3d/v3d_submit.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/4fa42a249e8cd6ed17aea04e5695b6e9001f2433 https://git.kernel.org/stable/c/9c5164781cb388d219d8f49fa0f0b04cf86ad544 https://git.kernel.org/stable/c/fb44d589bf3148e13452185a6e772a7efbf2d684