From 73644143b31cb95866c19e0d94be9e3127ec3a6b Mon Sep 17 00:00:00 2001
From: Qingqing Zhuo <qingqing.zhuo@amd.com>
Date: Wed, 9 Dec 2020 18:04:04 -0500
Subject: [PATCH] drm/amd/display: NULL pointer hang
[Why]
In dc_link_dp_set_test_pattern, we assume all pipes have a stream, which
can cause null pointer dereference.
[How]
Add a null pointer check before accessing stream.
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index 2fc12239b22cb..1bd1a09352906 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -3992,7 +3992,7 @@ bool dc_link_dp_set_test_pattern(
unsigned int cust_pattern_size)
{
struct pipe_ctx *pipes = link->dc->current_state->res_ctx.pipe_ctx;
- struct pipe_ctx *pipe_ctx = &pipes[0];
+ struct pipe_ctx *pipe_ctx = NULL;
unsigned int lane;
unsigned int i;
unsigned char link_qual_pattern[LANE_COUNT_DP_MAX] = {0};
@@ -4002,12 +4002,18 @@ bool dc_link_dp_set_test_pattern(
memset(&training_pattern, 0, sizeof(training_pattern));
for (i = 0; i < MAX_PIPES; i++) {
+ if (pipes[i].stream == NULL)
+ continue;
+
if (pipes[i].stream->link == link && !pipes[i].top_pipe && !pipes[i].prev_odm_pipe) {
pipe_ctx = &pipes[i];
break;
}
}
+ if (pipe_ctx == NULL)
+ return false;
+
/* Reset CRTC Test Pattern if it is currently running and request is VideoMode */
if (link->test_pattern_enabled && test_pattern ==
DP_TEST_PATTERN_VIDEO_MODE) {
--
2.30.2