drm/amd/display: Check num_valid_sets before accessing reader_wm_sets[]

[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@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Alex Hung 2024-04-16 16:22:35 -06:00 committed by Alex Deucher
parent 4e70c0f525
commit b38a4815f7

View File

@ -484,7 +484,8 @@ 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++;
}