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 E5F851A6803; Tue, 16 Jun 2026 17:11:07 +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=1781629868; cv=none; b=kYa1sBcQXx8FaBvabIMD2cLTWdkphCOU6FrCH1erFnivz0VoFts6qlCGb/sxO+29qOGpvOojC+FdKKYc7DQ5sYO+BR7UJaS7FWR17W9M4kWpOgo/ARXT0qiYvGo3qm/l3vU+GqIXlhjliyzKfjqOs+JHy4+DqUIvHfhvbx8HI5E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781629868; c=relaxed/simple; bh=M4BtW45Lw9diolu7vkTvQiOZv623+1gGCj6kmMiRwJU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pxJgePvUo2oCeQcsjknevcMRO7z9UwRtOFHY60xwSdIfZy/uiPBFsTsC436KFMzjhQG4I8ro3dLJV9+5684/um6/Ec6yWsdCE5EBC4RSMU01TPbxSStlvNC5sXFb7LoMRw+4D/weGjWC1anEwtoN1S2I37KqDk3zOyTTIP79UZ4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kqmygylx; 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="kqmygylx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED59A1F000E9; Tue, 16 Jun 2026 17:11:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781629867; bh=65yi1JsfwYwBJFp8AWkQ0mmZ9NyNdGtgpQdE5iXqzBg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=kqmygylxAi2AxUSUZx+fOgFv9COWLMjnv/WJsaxzCWahEQDttMNqhnZuPN+mrQ4Sp k11MFb7j2/yRoSXM1l2jvXS8YIS2hDGoP4DRx1XaHgs8/6/nOZxATeikHFcaGz38AR vNE4TUAaIq7xix17yTHUnDizxX1BHHZEZZOCI4QI= 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 6.6 366/452] drm/amd/display: Fix NULL deref and buffer over-read in SDP debugfs Date: Tue, 16 Jun 2026 20:29:53 +0530 Message-ID: <20260616145136.296139716@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145117.796205997@linuxfoundation.org> References: <20260616145117.796205997@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 6.6-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 @@ -1230,8 +1230,13 @@ 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;