From 4e497f1acd99075b13605b2e7fa0cba721a2cfd9 Mon Sep 17 00:00:00 2001 From: Wayne Lin Date: Fri, 8 Sep 2023 10:14:49 +0800 Subject: [PATCH] drm/amd/display: Avoid NULL dereference of timing generator [ Upstream commit b1904ed480cee3f9f4036ea0e36d139cb5fee2d6 ] [Why & How] Check whether assigned timing generator is NULL or not before accessing its funcs to prevent NULL dereference. Reviewed-by: Jun Lei Acked-by: Hersen Wu Signed-off-by: Wayne Lin Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/core/dc_stream.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c index f0f54f4d3d9b..5dd57cf170f5 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c @@ -562,7 +562,7 @@ uint32_t dc_stream_get_vblank_counter(const struct dc_stream_state *stream) for (i = 0; i < MAX_PIPES; i++) { struct timing_generator *tg = res_ctx->pipe_ctx[i].stream_res.tg; - if (res_ctx->pipe_ctx[i].stream != stream) + if (res_ctx->pipe_ctx[i].stream != stream || !tg) continue; return tg->funcs->get_frame_count(tg); @@ -621,7 +621,7 @@ bool dc_stream_get_scanoutpos(const struct dc_stream_state *stream, for (i = 0; i < MAX_PIPES; i++) { struct timing_generator *tg = res_ctx->pipe_ctx[i].stream_res.tg; - if (res_ctx->pipe_ctx[i].stream != stream) + if (res_ctx->pipe_ctx[i].stream != stream || !tg) continue; tg->funcs->get_scanoutpos(tg,