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 B0A5C2690D5; Sat, 30 May 2026 17:05:04 +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=1780160705; cv=none; b=YyPIobS2xKmkFvcuuGoEIW+tYhiAXQBGLIdWn2VRjE5F7/UAeSo2oPnRM2ObNE5zXMYaJ+RefB9V4Frk1TYbXiCWiFlOVNfJUZhC6B2OBIZJ/yDIaGV2ebcjS+/7WcWmHNzcVvMrgsJobNhNiWOVv3vtYEL7tv0+4RnzL+/fdq8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780160705; c=relaxed/simple; bh=qgbSh3jmRugaQPOth2Y5mZEyIcZwy7O0bGFMKTN2iVA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=OwO9DD8ZmSo99idWBFTvSO67mgnbdvGdM66qp90hs6hs/EsGj0SPCy0kRqWyKreIAGhkJL6EeTKXr2NCxz3x7O81wdo6+jT5GO9SKo3kswac30ll1XT9wLJ8UfXa4mYSqEXfZpZO2jMOwmiGbskwY6pDFpLRVC72aW5ategwVUA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=o0UOwssX; 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="o0UOwssX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 023401F00893; Sat, 30 May 2026 17:05:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780160704; bh=7TQLHbtNZmpd+Yl7RRj3sRA2UunBQKnTQI88Kz00ak8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=o0UOwssXDOQxQUaZMV1b1CnK32Mjxtl48XxCLq9jPxyeV5JwcsJhKylcErp0fpuES ECvpoQJPHP4QakpaZVGfxL//nCn/DMYcl3O0FtLmwMf7t7U78Q4++wf5sQ6ivsMLIT vLMxU0j+heqVhQw+WihXWRsNnxyk5NO/rp/dNEpQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Christian=20K=C3=B6nig?= , "John B. Moore" , Alex Deucher Subject: [PATCH 6.1 412/969] drm/amdgpu/sdma4: replace BUG_ON with WARN_ON in fence emission Date: Sat, 30 May 2026 17:58:56 +0200 Message-ID: <20260530160311.656085309@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160300.485627683@linuxfoundation.org> References: <20260530160300.485627683@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: John B. Moore commit 78d2e624fa073c14970aa097adcf3ea31c157a66 upstream. sdma_v4_0_ring_emit_fence() contains two BUG_ON(addr & 0x3) assertions that verify fence writeback addresses are dword-aligned. These assertions can be reached from unprivileged userspace via crafted DRM_IOCTL_AMDGPU_CS submissions, causing a fatal kernel panic in a scheduler worker thread. Replace both BUG_ON() calls with WARN_ON() to log the condition without crashing the kernel. A misaligned fence address at this point indicates a driver bug, but crashing the kernel is never the correct response when the assertion is reachable from userspace. The CS IOCTL path is the correct place to filter invalid submissions; the ring emission callback is too late to do anything about it. Fixes: 2130f89ced2c ("drm/amdgpu: add SDMA v4.0 implementation (v2)") Reviewed-by: Christian König Signed-off-by: John B. Moore Signed-off-by: Alex Deucher (cherry picked from commit b90250bd933afd1ba94d86d6b13821997b22b18e) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c @@ -884,7 +884,7 @@ static void sdma_v4_0_ring_emit_fence(st /* write the fence */ amdgpu_ring_write(ring, SDMA_PKT_HEADER_OP(SDMA_OP_FENCE)); /* zero in first two bits */ - BUG_ON(addr & 0x3); + WARN_ON(addr & 0x3); amdgpu_ring_write(ring, lower_32_bits(addr)); amdgpu_ring_write(ring, upper_32_bits(addr)); amdgpu_ring_write(ring, lower_32_bits(seq)); @@ -894,7 +894,7 @@ static void sdma_v4_0_ring_emit_fence(st addr += 4; amdgpu_ring_write(ring, SDMA_PKT_HEADER_OP(SDMA_OP_FENCE)); /* zero in first two bits */ - BUG_ON(addr & 0x3); + WARN_ON(addr & 0x3); amdgpu_ring_write(ring, lower_32_bits(addr)); amdgpu_ring_write(ring, upper_32_bits(addr)); amdgpu_ring_write(ring, upper_32_bits(seq));