[FFmpeg-devel] [PATCH 1/5] avformat/mov: Check a.size before computing next_root_atom

[Michael Niedermayer]

Fixes: signed integer overflow: 64 + 9223372036854775799 cannot be represented in type 'long'
Fixes: 27563/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6244650163372032

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavformat/mov.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 175d5a3cc2..194b6136b3 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -7065,7 +7065,7 @@ static int mov_read_default(MOVContext *c, AVIOContext *pb, MOVAtom atom)
                 c->atom_depth --;
                 return err;
             }
-            if (c->found_moov && c->found_mdat &&
+            if (c->found_moov && c->found_mdat && a.size <= INT64_MAX - start_pos &&
                 ((!(pb->seekable & AVIO_SEEKABLE_NORMAL) || c->fc->flags & AVFMT_FLAG_IGNIDX || c->frag_index.complete) ||
                  start_pos + a.size == avio_size(pb))) {
                 if (!(pb->seekable & AVIO_SEEKABLE_NORMAL) || c->fc->flags & AVFMT_FLAG_IGNIDX || c->frag_index.complete)
-- 
2.17.1