From 158b9201c17fc93ed4253c2f03b77fd2671669a1 Mon Sep 17 00:00:00 2001 From: Peichen Huang Date: Thu, 12 Jun 2025 16:06:41 +0800 Subject: [PATCH] drm/amd/display: add null check [WHY] Prevents null pointer dereferences to enhance function robustness [HOW] Adds early null check and return false if invalid. Reviewed-by: Cruise Hung Signed-off-by: Peichen Huang Signed-off-by: Ray Wu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/core/dc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c index 0146ad4e23c8..c744aa9d830f 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c @@ -6398,11 +6398,13 @@ unsigned int dc_get_det_buffer_size_from_state(const struct dc_state *context) */ bool dc_get_host_router_index(const struct dc_link *link, unsigned int *host_router_index) { - struct dc *dc = link->ctx->dc; + struct dc *dc; - if (link->ep_type != DISPLAY_ENDPOINT_USB4_DPIA) + if (!link || !host_router_index || link->ep_type != DISPLAY_ENDPOINT_USB4_DPIA) return false; + dc = link->ctx->dc; + if (link->link_index < dc->lowest_dpia_link_index) return false; -- 2.25.1