Messages in this thread Patch in this message |  | | From | Benjamin Gaignard <> | Subject | [PATCH] drm/dp_mst: Check crc4 value while building sideband message | Date | Mon, 3 Feb 2020 13:16:20 +0100 |
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Check that computed crc value is matching the one encoded in the message.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com> --- CC: lyude@redhat.com CC: airlied@linux.ie CC: jani.nikula@linux.intel.com drivers/gpu/drm/drm_dp_mst_topology.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 822d2f177f90..eee899d6742b 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; -- 2.15.0
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