6.6-stable review patch. If anyone has any objections, please let me know.
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From: Srinivasan Shanmugam srinivasan.shanmugam@amd.com
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@amd.com Cc: Rodrigo Siqueira Rodrigo.Siqueira@amd.com Cc: Roman Li roman.li@amd.com Cc: Alex Hung alex.hung@amd.com Cc: Aurabindo Pillai aurabindo.pillai@amd.com Cc: Harry Wentland harry.wentland@amd.com Cc: Hamza Mahfooz hamza.mahfooz@amd.com Signed-off-by: Srinivasan Shanmugam srinivasan.shanmugam@amd.com Reviewed-by: Alex Hung alex.hung@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org [Xiangyu: BP to fix CVE: CVE-2024-49915, modified the source path] Signed-off-by: Xiangyu Chen xiangyu.chen@windriver.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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)