[FFmpeg-cvslog] avcodec/snappy: Sanity check bytestream2_get_levarint()

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Sun Jan 19 21:51:11 2020 +0100| [0a8e5bab374441ac61376c532fa667f09bf88992] | committer: Michael Niedermayer

avcodec/snappy: Sanity check bytestream2_get_levarint()

Fixes: left shift of 79 by 28 places cannot be represented in type 'int'
Fixes: 20202/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HAP_fuzzer-5719004081815552
Fixes: 20219/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HAP_fuzzer-5641738677125120
Fixes: 20389/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HAP_fuzzer-5680721517871104

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 be54da2117a6f58c14283f2511e71fda8d3bfe9d)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0a8e5bab374441ac61376c532fa667f09bf88992
---

 libavcodec/snappy.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/snappy.c b/libavcodec/snappy.c
index 7900b0f978..f5c4c6578b 100644
--- a/libavcodec/snappy.c
+++ b/libavcodec/snappy.c
@@ -39,6 +39,8 @@ static int64_t bytestream2_get_levarint(GetByteContext *gb)
 
     do {
         tmp = bytestream2_get_byte(gb);
+        if (shift > 31 || ((tmp & 127LL) << shift) > INT_MAX)
+            return AVERROR_INVALIDDATA;
         val |= (tmp & 127) << shift;
         shift += 7;
     } while (tmp & 128);