From 9bacd42b1cc6a52e2ce5f7a69c17e336af69a47d Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Wed, 19 Jul 2017 14:43:28 +0300 Subject: [PATCH] drm/mst: Fix error handling during MST sideband message reception commit 448421b5e93b9177c5698f0cf6f5e72d2995eeca upstream. 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 Cc: Lyude Cc: Daniel Vetter Signed-off-by: Imre Deak Reviewed-by: Lyude Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20170719114330.26540-2-imre.deak@intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_dp_mst_topology.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index d3fc7e4e85b74..025c406f2744d 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -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; } -- 2.47.3