[FFmpeg-cvslog] avformat/4xm: Consider max_streams on reallocating tracks array

[Michael Niedermayer]

ffmpeg | branch: release/4.2 | Michael Niedermayer <michael at niedermayer.cc> | Tue Dec  7 09:14:08 2021 +0100| [f34273703b6a83bdb1471615e12abfcb14fca08a] | committer: Michael Niedermayer

avformat/4xm: Consider max_streams on reallocating tracks array

Fixes: OOM
Fixes: 41595/clusterfuzz-testcase-minimized-ffmpeg_dem_FOURXM_fuzzer-6355979363549184

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 0dcd95ef8a2e16ed930296567ab1044e33602a34)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=f34273703b6a83bdb1471615e12abfcb14fca08a
---

 libavformat/4xm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavformat/4xm.c b/libavformat/4xm.c
index bce99ad32f..c0c8cda713 100644
--- a/libavformat/4xm.c
+++ b/libavformat/4xm.c
@@ -137,7 +137,8 @@ static int parse_strk(AVFormatContext *s,
         return AVERROR_INVALIDDATA;
 
     track = AV_RL32(buf + 8);
-    if ((unsigned)track >= UINT_MAX / sizeof(AudioTrack) - 1) {
+    if ((unsigned)track >= UINT_MAX / sizeof(AudioTrack) - 1 ||
+        track >= s->max_streams) {
         av_log(s, AV_LOG_ERROR, "current_track too large\n");
         return AVERROR_INVALIDDATA;
     }