[PATCH AUTOSEL 6.6 10/83] drm/amd/display: Check index for aux_rd_interval before using

Sasha Levin
2024-08-01T00:21:59Z

From: Alex Hung <alex.hung@amd.com>

[ Upstream commit 9ba2ea6337b4f159aecb177555a6a81da92d302e ]

aux_rd_interval has size of 7 and should be checked.

This fixes 3 OVERRUN and 1 INTEGER_OVERFLOW issues reported by Coverity.

Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../gpu/drm/amd/display/dc/link/protocols/link_dp_training.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
index 16a62e0187122..9d1adfc09fb2a 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
+++ b/drivers/gpu/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(
--
2.43.0