From: Alex Hung <alex.hung@xxxxxxx> [ Upstream commit b38a4815f79b87efb196cd5121579fc51e29a7fb ] [WHY & HOW] num_valid_sets needs to be checked to avoid a negative index when accessing reader_wm_sets[num_valid_sets - 1]. This fixes an OVERRUN issue reported by Coverity. Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx> Acked-by: Tom Chung <chiahsuan.chung@xxxxxxx> Signed-off-by: Alex Hung <alex.hung@xxxxxxx> Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c index 6185f9475fa22..afce8f3bc67a2 100644 --- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c +++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c @@ -489,7 +489,8 @@ static void build_watermark_ranges(struct clk_bw_params *bw_params, struct pp_sm ranges->reader_wm_sets[num_valid_sets].max_fill_clk_mhz = PP_SMU_WM_SET_RANGE_CLK_UNCONSTRAINED_MAX; /* Modify previous watermark range to cover up to max */ - ranges->reader_wm_sets[num_valid_sets - 1].max_fill_clk_mhz = PP_SMU_WM_SET_RANGE_CLK_UNCONSTRAINED_MAX; + if (num_valid_sets > 0) + ranges->reader_wm_sets[num_valid_sets - 1].max_fill_clk_mhz = PP_SMU_WM_SET_RANGE_CLK_UNCONSTRAINED_MAX; } num_valid_sets++; } -- 2.43.0
