This is a note to let you know that I've just added the patch titled
drm/amd/display: Avoid NULL dereference of timing generator
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amd-display-avoid-null-dereference-of-timing-gen.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8c59f785a6540871659a54be9b0e6527b8d5e3dd
Author: Wayne Lin <wayne.lin@xxxxxxx>
Date: Fri Sep 8 10:14:49 2023 +0800
drm/amd/display: Avoid NULL dereference of timing generator
[ Upstream commit b1904ed480cee3f9f4036ea0e36d139cb5fee2d6 ]
[Why & How]
Check whether assigned timing generator is NULL or not before
accessing its funcs to prevent NULL dereference.
Reviewed-by: Jun Lei <jun.lei@xxxxxxx>
Acked-by: Hersen Wu <hersenxs.wu@xxxxxxx>
Signed-off-by: Wayne Lin <wayne.lin@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
index 01fe2d2fd2417..ebe571fcefe32 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
@@ -582,7 +582,7 @@ uint32_t dc_stream_get_vblank_counter(const struct dc_stream_state *stream)
for (i = 0; i < MAX_PIPES; i++) {
struct timing_generator *tg = res_ctx->pipe_ctx[i].stream_res.tg;
- if (res_ctx->pipe_ctx[i].stream != stream)
+ if (res_ctx->pipe_ctx[i].stream != stream || !tg)
continue;
return tg->funcs->get_frame_count(tg);
@@ -641,7 +641,7 @@ bool dc_stream_get_scanoutpos(const struct dc_stream_state *stream,
for (i = 0; i < MAX_PIPES; i++) {
struct timing_generator *tg = res_ctx->pipe_ctx[i].stream_res.tg;
- if (res_ctx->pipe_ctx[i].stream != stream)
+ if (res_ctx->pipe_ctx[i].stream != stream || !tg)
continue;
tg->funcs->get_scanoutpos(tg,
