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drm/amd/display: Add NULL pointer checks in dc_stream cursor attribute functions

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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: 4465dd0e41 ("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>
This commit is contained in:
Srinivasan Shanmugam
2025-08-13 12:14:01 +05:30
committed by Alex Deucher
parent 300d3e2d47
commit bf4e4b97d0
1 changed files with 7 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/gpu/drm/amd/display/dc/core/dc_stream.c
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@@ -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);