In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix potential null pointer dereference in dc_dmub_srv
Fixes potential null pointer dereference warnings in the dc_dmub_srv_cmd_list_queue_execute() and dc_dmub_srv_is_hw_pwr_up() functions.
In both functions, the dc_dmub_srv variable was being dereferenced before it was checked for null. This could lead to a null pointer dereference if dc_dmub_srv is null. The fix is to check if dc_dmub_srv is null before dereferencing it.
Thus moving the null checks for dc_dmub_srv to the beginning of the functions to ensure that dc_dmub_srv is not null when it is dereferenced.
Found by smatch & thus fixing the below: drivers/gpu/drm/amd/amdgpu/../display/dc/dc_dmub_srv.c:133 dc_dmub_srv_cmd_list_queue_execute() warn: variable dereferenced before check dc_dmub_srv (see line 128) drivers/gpu/drm/amd/amdgpu/../display/dc/dc_dmub_srv.c:1167 dc_dmub_srv_is_hw_pwr_up() warn: variable dereferenced before check dc_dmub_srv (see line 1164)