Commit 448421b5 authored Jul 19, 2017 by Imre Deak Committed by Daniel Vetter Jul 20, 2017

drm/mst: Fix error handling during MST sideband message reception



Handle any error due to partial reads, timeouts etc. to avoid parsing
uninitialized data subsequently. Also bail out if the parsing itself
fails.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Lyude <lyude@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Lyude <lyude@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170719114330.26540-2-imre.deak@intel.com

parent ef434a0c

drivers/gpu/drm/drm_dp_mst_topology.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -2196,11 +2196,17 @@ static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
		ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
		replyblock, len);
		if (ret != len) {
		DRM_DEBUG_KMS("failed to read a chunk\n");
		DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
		len, ret);
		return;
		}

		ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
		if (ret == false)
		if (!ret) {
		DRM_DEBUG_KMS("failed to build sideband msg\n");
		return;
		}

		curreply += len;
		replylen -= len;
		}