This is a note to let you know that I've just added the patch titled drm/amd/display: Add 'replay' NULL check in 'edp_set_replay_allow_active()' to the 6.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-amd-display-add-replay-null-check-in-edp_set_rep.patch and it can be found in the queue-6.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 978dc6378fec7f9b80b16f500b5e12ee6d5ee2e2 Author: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx> Date: Thu Feb 15 18:38:16 2024 +0530 drm/amd/display: Add 'replay' NULL check in 'edp_set_replay_allow_active()' [ Upstream commit f6aed043ee5d75b3d1bfc452b1a9584b63c8f76b ] In the first if statement, we're checking if 'replay' is NULL. But in the second if statement, we're not checking if 'replay' is NULL again before calling replay->funcs->replay_set_power_opt(). if (replay == NULL && force_static) return false; ... if (link->replay_settings.replay_feature_enabled && replay->funcs->replay_set_power_opt) { replay->funcs->replay_set_power_opt(replay, *power_opts, panel_inst); link->replay_settings.replay_power_opt_active = *power_opts; } If 'replay' is NULL, this will cause a null pointer dereference. Fixes the below found by smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/link/protocols/link_edp_panel_control.c:895 edp_set_replay_allow_active() error: we previously assumed 'replay' could be null (see line 887) Fixes: c7ddc0a800bc ("drm/amd/display: Add Functions to enable Freesync Panel Replay") Cc: Bhawanpreet Lakha <Bhawanpreet.Lakha@xxxxxxx> Cc: Roman Li <roman.li@xxxxxxx> Cc: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx> Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx> Cc: Tom Chung <chiahsuan.chung@xxxxxxx> Suggested-by: Tom Chung <chiahsuan.chung@xxxxxxx> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx> Reviewed-by: Tom Chung <chiahsuan.chung@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c index 046d3e2054153..f1489f4a40c12 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c @@ -892,7 +892,8 @@ bool edp_set_replay_allow_active(struct dc_link *link, const bool *allow_active, /* Set power optimization flag */ if (power_opts && link->replay_settings.replay_power_opt_active != *power_opts) { - if (link->replay_settings.replay_feature_enabled && replay->funcs->replay_set_power_opt) { + if (replay != NULL && link->replay_settings.replay_feature_enabled && + replay->funcs->replay_set_power_opt) { replay->funcs->replay_set_power_opt(replay, *power_opts, panel_inst); link->replay_settings.replay_power_opt_active = *power_opts; }