[FFmpeg-cvslog] avformat/aiffdec: Check size before subtraction in get_aiff_header()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Nov 10 23:01:12 2020 +0100| [8af299acde9601e64740b75430960503615873b4] | committer: Michael Niedermayer

avformat/aiffdec: Check size before subtraction in get_aiff_header()

Fixes: Infinite loop
Fixes: 27235/clusterfuzz-testcase-minimized-ffmpeg_dem_AIFF_fuzzer-5761398380167168

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=8af299acde9601e64740b75430960503615873b4
---

 libavformat/aiffdec.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavformat/aiffdec.c b/libavformat/aiffdec.c
index 15733478e1..4d1c9bbb53 100644
--- a/libavformat/aiffdec.c
+++ b/libavformat/aiffdec.c
@@ -120,6 +120,8 @@ static int get_aiff_header(AVFormatContext *s, int size,
     else
         sample_rate = (val + (1ULL<<(-exp-1))) >> -exp;
     par->sample_rate = sample_rate;
+    if (size < 18)
+        return AVERROR_INVALIDDATA;
     size -= 18;
 
     /* get codec id for AIFF-C */