From 59d99deb330af206a4541db0c4da8f73880fba03 Mon Sep 17 00:00:00 2001
From: Alex Hung <alex.hung@amd.com>
Date: Thu, 18 Apr 2024 13:27:43 -0600
Subject: [PATCH] drm/amd/display: Check index msg_id before read or write
[WHAT]
msg_id is used as an array index and it cannot be a negative value, and
therefore cannot be equal to MOD_HDCP_MESSAGE_ID_INVALID (-1).
[HOW]
Check whether msg_id is valid before reading and setting.
This fixes 4 OVERRUN issues reported by Coverity.
Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c
index f7b5583ee609..8e9caae7c955 100644
--- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c
+++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c
@@ -156,6 +156,10 @@ static enum mod_hdcp_status read(struct mod_hdcp *hdcp,
uint32_t cur_size = 0;
uint32_t data_offset = 0;
+ if (msg_id == MOD_HDCP_MESSAGE_ID_INVALID) {
+ return MOD_HDCP_STATUS_DDC_FAILURE;
+ }
+
if (is_dp_hdcp(hdcp)) {
while (buf_len > 0) {
cur_size = MIN(buf_len, HDCP_MAX_AUX_TRANSACTION_SIZE);
@@ -215,6 +219,10 @@ static enum mod_hdcp_status write(struct mod_hdcp *hdcp,
uint32_t cur_size = 0;
uint32_t data_offset = 0;
+ if (msg_id == MOD_HDCP_MESSAGE_ID_INVALID) {
+ return MOD_HDCP_STATUS_DDC_FAILURE;
+ }
+
if (is_dp_hdcp(hdcp)) {
while (buf_len > 0) {
cur_size = MIN(buf_len, HDCP_MAX_AUX_TRANSACTION_SIZE);