[FFmpeg-devel] [PATCH] lavc/vvc: Fix slice_idx out-of-bounds memset
post at frankplowman.com
post at frankplowman.com
Mon Feb 5 20:00:05 EET 2024
From: Frank Plowman <post at frankplowman.com>
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 <post at frankplowman.com>
---
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);
--
2.43.0
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