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authorBenjamin Gaignard <benjamin.gaignard@st.com>2020-02-03 13:16:20 +0100
committerBenjamin Gaignard <benjamin.gaignard@st.com>2020-02-28 13:08:00 +0100
commitd6b8bbca6bc83b9c57e528b28df6177b9b57e19d (patch)
tree59f3563521cf06c264d5036a5d50bb6b77edbbe3 /drivers/gpu/drm
parentcb897542c6d2b34c7203b1a2e030ff35e100eef8 (diff)
downloadlinux-d6b8bbca6bc83b9c57e528b28df6177b9b57e19d.tar.bz2
drm/dp_mst: Check crc4 value while building sideband message
Check that computed crc value is matching the one encoded in the message. Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200203121620.9002-1-benjamin.gaignard@st.com
Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r--drivers/gpu/drm/drm_dp_mst_topology.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index ba15a15bce9e..61e7beada832 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -736,6 +736,10 @@ static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
if (msg->curchunk_idx >= msg->curchunk_len) {
/* do CRC */
crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
+ if (crc4 != msg->chunk[msg->curchunk_len - 1])
+ print_hex_dump(KERN_DEBUG, "wrong crc",
+ DUMP_PREFIX_NONE, 16, 1,
+ msg->chunk, msg->curchunk_len, false);
/* copy chunk into bigger msg */
memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
msg->curlen += msg->curchunk_len - 1;