drm/amd/display: Check index for aux_rd_interval before using

From Alex Hung
48e0b68e2360b16edf2a0bae05c0051c00fbb48a in linux-6.6.y/6.6.50
9ba2ea6337b4f159aecb177555a6a81da92d302e in mainline linux

diff --git a/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_training.c b/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_training.c
index cda3f72..d14e624 100644 (file)
--- a/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_training.c
+++ b/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_training.c
@@ -914,10 +914,10 @@ static enum dc_status configure_lttpr_mode_non_transparent(
                        /* Driver does not need to train the first hop. Skip DPCD read and clear
                         * AUX_RD_INTERVAL for DPTX-to-DPIA hop.
                         */
-                       if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)
+                       if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA && repeater_cnt > 0 && repeater_cnt < MAX_REPEATER_CNT)
                                link->dpcd_caps.lttpr_caps.aux_rd_interval[--repeater_cnt] = 0;
 
-                       for (repeater_id = repeater_cnt; repeater_id > 0; repeater_id--) {
+                       for (repeater_id = repeater_cnt; repeater_id > 0 && repeater_id < MAX_REPEATER_CNT; repeater_id--) {
                                aux_interval_address = DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1 +
                                                ((DP_REPEATER_CONFIGURATION_AND_STATUS_SIZE) * (repeater_id - 1));
                                core_link_read_dpcd(