avcodec/wmadec: Require previous exponents for reuse

Fixes: division by zero
Fixes: 18474/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WMAV2_fuzzer-5764986962182144

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2019-10-31 14:38:16 +01:00
parent 7fc1baf0ca
commit c54b9fc42f
2 changed files with 4 additions and 0 deletions

View File

@ -123,6 +123,7 @@ typedef struct WMACodecContext {
uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + AV_INPUT_BUFFER_PADDING_SIZE]; /* padding added */
int last_bitoffset;
int last_superframe_len;
int exponents_initialized;
float noise_table[NOISE_TAB_SIZE];
int noise_index;
float noise_mult; /* XXX: suppress that and integrate it in the noise array */

View File

@ -587,6 +587,9 @@ static int wma_decode_block(WMACodecContext *s)
s->exponents_bsize[ch] = bsize;
}
}
s->exponents_initialized = 1;
}else if (!s->exponents_initialized) {
return AVERROR_INVALIDDATA;
}
/* parse spectral coefficients : just RLE encoding */