[PATCH AUTOSEL 6.9 16/22] drm/amd/display: Fix array-index-out-of-bounds in dml2/FCLKChangeSupport

[Sasha Levin]

From: Roman Li <Roman.Li at amd.com>

[ Upstream commit 0ad4b4a2f6357c45fbe444ead1a929a0b4017d03 ]

[Why]
Potential out of bounds access in dml2_calculate_rq_and_dlg_params()
because the value of out_lowest_state_idx used as an index for FCLKChangeSupport
array can be greater than 1.

[How]
Currently dml2 core specifies identical values for all FCLKChangeSupport
elements. Always use index 0 in the condition to avoid out of bounds access.

Acked-by: Rodrigo Siqueira <rodrigo.siqueira at amd.com>
Signed-off-by: Jerry Zuo <jerry.zuo at amd.com>
Signed-off-by: Roman Li <Roman.Li at amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/gpu/drm/amd/display/dc/dml2/dml2_utils.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml2_utils.c b/drivers/gpu/drm/amd/display/dc/dml2/dml2_utils.c
index b72ed3e78df05..bb4e812248aec 100644
--- a/drivers/gpu/drm/amd/display/dc/dml2/dml2_utils.c
+++ b/drivers/gpu/drm/amd/display/dc/dml2/dml2_utils.c
@@ -294,7 +294,7 @@ void dml2_calculate_rq_and_dlg_params(const struct dc *dc, struct dc_state *cont
 	context->bw_ctx.bw.dcn.clk.dcfclk_deep_sleep_khz = (unsigned int)in_ctx->v20.dml_core_ctx.mp.DCFCLKDeepSleep * 1000;
 	context->bw_ctx.bw.dcn.clk.dppclk_khz = 0;
 
-	if (in_ctx->v20.dml_core_ctx.ms.support.FCLKChangeSupport[in_ctx->v20.scratch.mode_support_params.out_lowest_state_idx] == dml_fclock_change_unsupported)
+	if (in_ctx->v20.dml_core_ctx.ms.support.FCLKChangeSupport[0] == dml_fclock_change_unsupported)
 		context->bw_ctx.bw.dcn.clk.fclk_p_state_change_support = false;
 	else
 		context->bw_ctx.bw.dcn.clk.fclk_p_state_change_support = true;
-- 
2.43.0