From: Alex Hung alex.hung@amd.com

stable inclusion from stable-v6.6.50 commit 21f9cb44f8c60bf6c26487d428b1a09ad3e8aebf category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAP55A

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ 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@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 Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: ZhangPeng zhangpeng362@huawei.com --- 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 0c6a4ab72b1d..97cdc24cef9a 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 @@ -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++; }