From a42f884cd2fafb7aa53bf7b56c20355cd61ca1f5 Mon Sep 17 00:00:00 2001 From: Frank Plowman Date: Mon, 5 Feb 2024 18:00:05 +0000 Subject: lavc/vvc: Fix slice_idx out-of-bounds memset If the number of CTUs reduces between one picture and the next, the slice_idx table is reduced in size in the frame_context_for_each_tl call on vvcdec.c:321. When initialising the slice_idx table on vvcdec.c:325, the old code uses fc->tab.sz.ctu_count when calculating the table size. fc->tab.sz.ctu_count holds the old ctu count at this point however, not being updated to hold the new ctu count until vvcdec.c:342. This causes an out-of-bounds write. Patch fixes the problem by using pps->ctb_count, which was just used when allocating the table, in place of fc->tab.sz.ctu_count when initialising the table. Signed-off-by: Frank Plowman --- libavcodec/vvc/vvcdec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/vvc/vvcdec.c b/libavcodec/vvc/vvcdec.c index 1a050600eb..8163b5ecb6 100644 --- a/libavcodec/vvc/vvcdec.c +++ b/libavcodec/vvc/vvcdec.c @@ -322,7 +322,7 @@ static int pic_arrays_init(VVCContext *s, VVCFrameContext *fc) if (ret < 0) return ret; - memset(fc->tab.slice_idx, -1, sizeof(*fc->tab.slice_idx) * fc->tab.sz.ctu_count); + memset(fc->tab.slice_idx, -1, sizeof(*fc->tab.slice_idx) * ctu_count); if (fc->tab.sz.ctu_count != ctu_count) { ff_refstruct_pool_uninit(&fc->rpl_tab_pool); -- cgit v1.2.3