From: Srinivasan Shanmugam <srinivasan.shanmu...@amd.com>
[ Upstream commit f22f4754aaa47d8c59f166ba3042182859e5dff7 ]
This commit addresses a potential null pointer dereference issue in the
`dcn201_acquire_free_pipe_for_layer` function. The issue could occur
when `head_pipe` is null.
The fix adds a check to ensure `head_pipe` is not null before asserting
it. If `head_pipe` is null, the function returns NULL to prevent a
potential null pointer dereference.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn201/dcn201_resource.c:1016
dcn201_acquire_free_pipe_for_layer() error: we previously assumed 'head_pipe'
could be null (see line 1010)
Cc: Tom Chung <chiahsuan.ch...@amd.com>
Cc: Rodrigo Siqueira <rodrigo.sique...@amd.com>
Cc: Roman Li <roman...@amd.com>
Cc: Alex Hung <alex.h...@amd.com>
Cc: Aurabindo Pillai <aurabindo.pil...@amd.com>
Cc: Harry Wentland <harry.wentl...@amd.com>
Cc: Hamza Mahfooz <hamza.mahf...@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmu...@amd.com>
Reviewed-by: Tom Chung <chiahsuan.ch...@amd.com>
Signed-off-by: Alex Deucher <alexander.deuc...@amd.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
.../gpu/drm/amd/display/dc/resource/dcn201/dcn201_resource.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn201/dcn201_resource.c
b/drivers/gpu/drm/amd/display/dc/resource/dcn201/dcn201_resource.c
index 070a4efb308bd..1aeede348bd39 100644
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn201/dcn201_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn201/dcn201_resource.c
@@ -1005,8 +1005,10 @@ static struct pipe_ctx
*dcn201_acquire_free_pipe_for_layer(
struct pipe_ctx *head_pipe =
resource_get_otg_master_for_stream(res_ctx, opp_head_pipe->stream);
struct pipe_ctx *idle_pipe =
resource_find_free_secondary_pipe_legacy(res_ctx, pool, head_pipe);
- if (!head_pipe)
+ if (!head_pipe) {
ASSERT(0);
+ return NULL;
+ }
if (!idle_pipe)
return NULL;
--
2.43.0
