[FFmpeg-devel] [PATCH 3/5] avcodec/wmalosslessdec: Check that padding bits is not more than sample bits

Michael Niedermayer michael at niedermayer.cc
Mon Nov 18 18:30:12 EET 2019


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

diff --git a/libavcodec/wmalosslessdec.c b/libavcodec/wmalosslessdec.c
index d4f18b9841..45740a090b 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);
-- 
2.23.0



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