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 76139477E57; Tue, 16 Jun 2026 16:36:22 +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=1781627783; cv=none; b=AVki1Lu73a+J6h9iOt/sVM0ill6iX3MrMRgaBcQFQVE5hAqI+ojJzaNSDBf6cxlQ9zJl7vNiucXRpCXzuvkJhAfJOhfuh1TZv5krSvkpIxx9wxrJ5nCGOZePxR9/eciHbJYW0VCacbNzjGkO9RCNmBJPdDwsstracPzf5s5bxWc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781627783; c=relaxed/simple; bh=y0H9PTjc077YxTYeZ3OEzgv+P6Q1WPg1Q1DMeuGle3I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GGbnjCfz8q91t+QvXn+5TAMnvBOBzwFB9fBEpYS9LuUTZABqpevXdHHc2WJnYNYuGEhsALJDdFldbBZ7FI3p2CF+oKdx1Ur1CRsnJt79cJlDNBlnkLY3VVqaMR700aeNcKEmUr2/7/mtXHVg5GSIRn9NG7Vduw4+3sl/o8WNr3I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=RyPYIXXO; 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="RyPYIXXO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C9011F000E9; Tue, 16 Jun 2026 16:36:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781627782; bh=I/tIPMfJvKbN/eaLppRebFT24gQU7h5MGruL4FCuOeg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=RyPYIXXOe83T+8WvanhljIjSvpMUbaQX37j7AeibuPZmeU2u6SLhwoP3JpTrtU3PP pVTTbkKTpkkcvRKtLzInR7HCb0q6t/nkhQKQnJQgyZQwEC5cbdQZf76wS+MrinseRV BbRHdvTIgi9B5yFNNWLPpFdFRxmqovATZPkMKGdM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alex Hung , Harry Wentland , Ray Wu , Daniel Wheeler , Alex Deucher Subject: [PATCH 6.12 227/261] drm/amd/display: Fix NULL deref and buffer over-read in SDP debugfs Date: Tue, 16 Jun 2026 20:31:05 +0530 Message-ID: <20260616145055.549337962@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145044.869532709@linuxfoundation.org> References: <20260616145044.869532709@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-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Harry Wentland commit adf67034b1f61f7119295208085bfd43f85f56af upstream. [Why & How] dp_sdp_message_debugfs_write() dereferences connector->base.state->crtc without checking for NULL. A connector can be connected but not bound to any CRTC (e.g. after hot-plug before the next atomic commit), causing a kernel crash when writing to the sdp_message debugfs node. The function also ignores the user-provided size argument and always passes 36 bytes to copy_from_user(), reading past the user buffer when size < 36. Fix both issues by: - Returning -ENODEV when connector->base.state or state->crtc is NULL - Clamping write_size to min(size, sizeof(data)) Fixes: c7ba3653e977 ("drm/amd/display: Generic SDP message access in amdgpu") Assisted-by: Copilot:claude-opus-4.6 Reviewed-by: Alex Hung Signed-off-by: Harry Wentland Signed-off-by: Ray Wu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 6ab4c36a522842ff70474a1c0af2e40e50fc8300) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c @@ -1314,8 +1314,13 @@ static ssize_t dp_sdp_message_debugfs_wr if (size == 0) return 0; + if (!connector->base.state || !connector->base.state->crtc) + return -ENODEV; + acrtc_state = to_dm_crtc_state(connector->base.state->crtc->state); + write_size = min_t(size_t, size, sizeof(data)); + r = copy_from_user(data, buf, write_size); write_size -= r;