In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Add null check for head_pipe in dcn32_acquire_idle_pipe_for_head_pipe_in_layer

This commit addresses a potential null pointer dereference issue in the
`dcn32_acquire_idle_pipe_for_head_pipe_in_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/dcn32/dcn32_resource.c:2690 dcn32_acquire_idle_pipe_for_head_pipe_in_layer() error: we previously assumed 'head_pipe' could be null (see line 2681)

kernel.org https://git.kernel.org/stable/c/4f47292f488fa7041284dca1f1244116c18721f1 [No types assigned]

kernel.org https://git.kernel.org/stable/c/96d4c2ee18d732a248d053aae8c4a27cb1d68d1c [No types assigned]

kernel.org https://git.kernel.org/stable/c/ac2140449184a26eac99585b7f69814bd3ba8f2d [No types assigned]