Merge v7.1.6linux-rolling-stable

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 20 insertions, 16 deletions

diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index 8757972e8e24..41151c533d2f 100644
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -789,6 +789,12 @@ static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg,
 {
 	u8 crc4;
 
+	/* curchunk_len must be >= 1 (min 1 CRC byte) and fit in chunk[] */
+	if (!msg->curchunk_len ||
+	    msg->curchunk_len > ARRAY_SIZE(msg->chunk) ||
+	    msg->curchunk_idx + replybuflen > ARRAY_SIZE(msg->chunk))
+		return false;
+
 	memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
 	msg->curchunk_idx += replybuflen;
 
@@ -799,6 +805,9 @@ static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg,
 			print_hex_dump(KERN_DEBUG, "wrong crc",
 				       DUMP_PREFIX_NONE, 16, 1,
 				       msg->chunk,  msg->curchunk_len, false);
+		/* Guard against accumulated msg[] overflow */
+		if (msg->curlen + msg->curchunk_len - 1 > ARRAY_SIZE(msg->msg))
+			return false;
 		/* copy chunk into bigger msg */
 		memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
 		msg->curlen += msg->curchunk_len - 1;
@@ -871,7 +880,7 @@ static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx
 		goto fail_len;
 	repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
 	idx++;
-	if (idx > raw->curlen)
+	if (idx + repmsg->u.remote_dpcd_read_ack.num_bytes > raw->curlen)
 		goto fail_len;
 
 	memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
@@ -907,7 +916,9 @@ static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg
 		goto fail_len;
 	repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
 	idx++;
-	/* TODO check */
+	if (idx + repmsg->u.remote_i2c_read_ack.num_bytes > raw->curlen)
+		goto fail_len;
+
 	memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
 	return true;
 fail_len:
@@ -923,16 +934,13 @@ static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband
 	repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
 	repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
 	idx++;
-	if (idx > raw->curlen)
+	if (idx + 2 > raw->curlen)
 		goto fail_len;
 	repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 	idx += 2;
-	if (idx > raw->curlen)
+	if (idx + 2 > raw->curlen)
 		goto fail_len;
 	repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
-	idx += 2;
-	if (idx > raw->curlen)
-		goto fail_len;
 	return true;
 fail_len:
 	DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
@@ -950,12 +958,9 @@ static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_ms
 		goto fail_len;
 	repmsg->u.allocate_payload.vcpi = raw->msg[idx];
 	idx++;
-	if (idx > raw->curlen)
+	if (idx + 2 > raw->curlen)
 		goto fail_len;
 	repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
-	idx += 2;
-	if (idx > raw->curlen)
-		goto fail_len;
 	return true;
 fail_len:
 	DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
@@ -969,12 +974,9 @@ static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_r
 
 	repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
 	idx++;
-	if (idx > raw->curlen)
+	if (idx + 2 > raw->curlen)
 		goto fail_len;
 	repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
-	idx += 2;
-	if (idx > raw->curlen)
-		goto fail_len;
 	return true;
 fail_len:
 	DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
@@ -3738,8 +3740,10 @@ void drm_dp_mst_topology_queue_probe(struct drm_dp_mst_topology_mgr *mgr)
 {
 	mutex_lock(&mgr->lock);
 
-	if (drm_WARN_ON(mgr->dev, !mgr->mst_state || !mgr->mst_primary))
+	if (!mgr->mst_state || !mgr->mst_primary) {
+		drm_dbg_kms(mgr->dev, "queue_probe skipped: topology torn down\n");
 		goto out_unlock;
+	}
 
 	drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary);
 	drm_dp_mst_queue_probe_work(mgr);