[FFmpeg-cvslog] avcodec/wmalosslessdec: Check that padding bits is not more than sample bits

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Mon Nov 18 12:49:25 2019 +0100| [9d428265808255ad2fc60355fe641aaa4fd3dae4] | committer: Michael Niedermayer

avcodec/wmalosslessdec: Check that padding bits is not more than sample bits

Fixes: left shift of 1 by 31 places cannot be represented in type 'int'
Fixes: 18817/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WMALOSSLESS_fuzzer-5713317180211200

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=9d428265808255ad2fc60355fe641aaa4fd3dae4
---

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

diff --git a/libavcodec/wmalosslessdec.c b/libavcodec/wmalosslessdec.c
index 7ed6ce3135..9489338cef 100644
--- a/libavcodec/wmalosslessdec.c
+++ b/libavcodec/wmalosslessdec.c
@@ -950,6 +950,8 @@ static int decode_subframe(WmallDecodeCtx *s)
             for (j = 0; j < subframe_len; j++)
                 s->channel_residues[i][j] = get_sbits_long(&s->gb, bits);
     } else {
+        if (s->bits_per_sample < padding_zeroes)
+            return AVERROR_INVALIDDATA;
         for (i = 0; i < s->num_channels; i++) {
             if (s->is_channel_coded[i]) {
                 decode_channel_residues(s, i, subframe_len);