From bf5c850b795126d4f60dd9498c06f0492f5726a7 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 30 Nov 2019 16:46:46 +0100 Subject: [PATCH] avcodec/wmadec: Keep track of exponent initialization per channel Fixes: division by 0 Fixes: 19123/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WMAV2_fuzzer-5655493121146880 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/wma.h | 2 +- libavcodec/wmadec.c | 9 ++++++--- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/libavcodec/wma.h b/libavcodec/wma.h index 8344cb5b93..c7fcf5047c 100644 --- a/libavcodec/wma.h +++ b/libavcodec/wma.h @@ -123,7 +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; + int exponents_initialized[MAX_CHANNELS]; float noise_table[NOISE_TAB_SIZE]; int noise_index; float noise_mult; /* XXX: suppress that and integrate it in the noise array */ diff --git a/libavcodec/wmadec.c b/libavcodec/wmadec.c index bb9bc8d236..6365fe7f47 100644 --- a/libavcodec/wmadec.c +++ b/libavcodec/wmadec.c @@ -585,11 +585,14 @@ static int wma_decode_block(WMACodecContext *s) decode_exp_lsp(s, ch); } s->exponents_bsize[ch] = bsize; + s->exponents_initialized[ch] = 1; } } - s->exponents_initialized = 1; - }else if (!s->exponents_initialized) { - return AVERROR_INVALIDDATA; + } + + for (ch = 0; ch < s->avctx->channels; ch++) { + if (s->channel_coded[ch] && !s->exponents_initialized[ch]) + return AVERROR_INVALIDDATA; } /* parse spectral coefficients : just RLE encoding */