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
This commit is contained in:
Imre Deak 2017-07-19 14:43:28 +03:00 committed by Daniel Vetter
parent ef434a0c2c
commit 448421b5e9

View file

@ -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;
}