6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx> commit c395fd47d1565bd67671f45cca281b3acc2c31ef upstream. This commit addresses a potential null pointer dereference issue in the `dcn32_init_hw` function. The issue could occur when `dc->clk_mgr` is null. The fix adds a check to ensure `dc->clk_mgr` is not null before accessing its functions. This prevents a potential null pointer dereference. Reported by smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn32/dcn32_hwseq.c:961 dcn32_init_hw() error: we previously assumed 'dc->clk_mgr' could be null (see line 782) Cc: Tom Chung <chiahsuan.chung@xxxxxxx> Cc: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx> Cc: Roman Li <roman.li@xxxxxxx> Cc: Alex Hung <alex.hung@xxxxxxx> Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx> Cc: Harry Wentland <harry.wentland@xxxxxxx> Cc: Hamza Mahfooz <hamza.mahfooz@xxxxxxx> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx> Reviewed-by: Alex Hung <alex.hung@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> [Xiangyu: BP to fix CVE: CVE-2024-49915, modified the source path] Signed-off-by: Xiangyu Chen <xiangyu.chen@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c @@ -773,7 +773,7 @@ void dcn32_init_hw(struct dc *dc) int edp_num; uint32_t backlight = MAX_BACKLIGHT_LEVEL; - if (dc->clk_mgr && dc->clk_mgr->funcs->init_clocks) + if (dc->clk_mgr && dc->clk_mgr->funcs && dc->clk_mgr->funcs->init_clocks) dc->clk_mgr->funcs->init_clocks(dc->clk_mgr); // Initialize the dccg @@ -950,10 +950,11 @@ void dcn32_init_hw(struct dc *dc) if (!dcb->funcs->is_accelerated_mode(dcb) && dc->res_pool->hubbub->funcs->init_watermarks) dc->res_pool->hubbub->funcs->init_watermarks(dc->res_pool->hubbub); - if (dc->clk_mgr->funcs->notify_wm_ranges) + if (dc->clk_mgr && dc->clk_mgr->funcs && dc->clk_mgr->funcs->notify_wm_ranges) dc->clk_mgr->funcs->notify_wm_ranges(dc->clk_mgr); - if (dc->clk_mgr->funcs->set_hard_max_memclk && !dc->clk_mgr->dc_mode_softmax_enabled) + if (dc->clk_mgr && dc->clk_mgr->funcs && dc->clk_mgr->funcs->set_hard_max_memclk && + !dc->clk_mgr->dc_mode_softmax_enabled) dc->clk_mgr->funcs->set_hard_max_memclk(dc->clk_mgr); if (dc->res_pool->hubbub->funcs->force_pstate_change_control)
