[FFmpeg-cvslog] avformat/iff: More completely check body_size

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Wed Oct 21 22:56:17 2020 +0200| [3588e2e6b05ba92f0907e9ffe263c2e65d53e346] | committer: Michael Niedermayer

avformat/iff: More completely check body_size

Fixes: infinite loop
Fixes: 26485/clusterfuzz-testcase-minimized-ffmpeg_dem_IFF_fuzzer-5126561373880320

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3588e2e6b05ba92f0907e9ffe263c2e65d53e346
---

 libavformat/iff.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavformat/iff.c b/libavformat/iff.c
index 04fe8be4eb..fb76aed4c3 100644
--- a/libavformat/iff.c
+++ b/libavformat/iff.c
@@ -839,7 +839,7 @@ static int iff_read_packet(AVFormatContext *s,
         } else if (st->codecpar->codec_tag == ID_DST) {
             return read_dst_frame(s, pkt);
         } else {
-            if (iff->body_size > INT_MAX)
+            if (iff->body_size > INT_MAX || !iff->body_size)
                 return AVERROR_INVALIDDATA;
             ret = av_get_packet(pb, pkt, iff->body_size);
         }
@@ -875,6 +875,8 @@ static int iff_read_packet(AVFormatContext *s,
             pkt->flags |= AV_PKT_FLAG_KEY;
     } else if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
                st->codecpar->codec_tag  != ID_ANIM) {
+        if (iff->body_size > INT_MAX || !iff->body_size)
+            return AVERROR_INVALIDDATA;
         ret = av_get_packet(pb, pkt, iff->body_size);
         pkt->pos = pos;
         if (pos == iff->body_pos)