6.17-stable review patch. If anyone has any objections, please let me know.
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From: Srinivasan Shanmugam srinivasan.shanmugam@amd.com
[ Upstream commit bf4e4b97d0fdc66f04fc19d807e24dd8421b8f11 ]
The function dc_stream_set_cursor_attributes() currently dereferences the `stream` pointer and nested members `stream->ctx->dc->current_state` without checking for NULL.
All callers of these functions, such as in `dcn30_apply_idle_power_optimizations()` and `amdgpu_dm_plane_handle_cursor_update()`, already perform NULL checks before calling these functions.
Fixes below: drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c:336 dc_stream_program_cursor_attributes() error: we previously assumed 'stream' could be null (see line 334)
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c 327 bool dc_stream_program_cursor_attributes( 328 struct dc_stream_state *stream, 329 const struct dc_cursor_attributes *attributes) 330 { 331 struct dc *dc; 332 bool reset_idle_optimizations = false; 333 334 dc = stream ? stream->ctx->dc : NULL; ^^^^^^ The old code assumed stream could be NULL.
335 --> 336 if (dc_stream_set_cursor_attributes(stream, attributes)) { ^^^^^^ The refactor added an unchecked dereference.
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_stream.c 313 bool dc_stream_set_cursor_attributes( 314 struct dc_stream_state *stream, 315 const struct dc_cursor_attributes *attributes) 316 { 317 bool result = false; 318 319 if (dc_stream_check_cursor_attributes(stream, stream->ctx->dc->current_state, attributes)) { ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Here. This function used to check for if stream as NULL and return false at the start. Probably we should add that back.
Fixes: 4465dd0e41e8 ("drm/amd/display: Refactor SubVP cursor limiting logic") Reported-by: Dan Carpenter dan.carpenter@linaro.org Cc: Alex Hung alex.hung@amd.com Cc: Alvin Lee alvin.lee2@amd.com Cc: Ray Wu ray.wu@amd.com Cc: Dillon Varone dillon.varone@amd.com Cc: Aurabindo Pillai aurabindo.pillai@amd.com Cc: Roman Li roman.li@amd.com Cc: ChiaHsuan Chung chiahsuan.chung@amd.com Cc: Harry Wentland harry.wentland@amd.com Cc: Daniel Wheeler daniel.wheeler@amd.com Cc: Tom Chung chiahsuan.chung@amd.com Cc: Wenjing Liu wenjing.liu@amd.com Cc: Jun Lei Jun.Lei@amd.com Signed-off-by: Srinivasan Shanmugam srinivasan.shanmugam@amd.com Reviewed-by: Dillon Varone Dillon.varone@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/core/dc_stream.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
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 4d6bc9fd4faa8..9ac2d41f8fcae 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c @@ -316,6 +316,9 @@ bool dc_stream_set_cursor_attributes( { bool result = false;
+ if (!stream) + return false; + if (dc_stream_check_cursor_attributes(stream, stream->ctx->dc->current_state, attributes)) { stream->cursor_attributes = *attributes; result = true; @@ -331,7 +334,10 @@ bool dc_stream_program_cursor_attributes( struct dc *dc; bool reset_idle_optimizations = false;
- dc = stream ? stream->ctx->dc : NULL; + if (!stream) + return false; + + dc = stream->ctx->dc;
if (dc_stream_set_cursor_attributes(stream, attributes)) { dc_z10_restore(dc);