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| author | Ronald S. Bultje <rsbultje@gmail.com> | 2012-03-01 16:19:51 -0800 |
|---|---|---|
| committer | Ronald S. Bultje <rsbultje@gmail.com> | 2012-03-02 10:31:28 -0800 |
| commit | 349b7977e408f18cff01ab31dfa66c8249b6584a (patch) | |
| tree | 3ed1960676d4b9552e738c48a1bd187eb9a042e0 | |
| parent | 9d25f1f6194dba9cfd60c0596aa59ad145d61382 (diff) | |
| download | ffmpeg-349b7977e408f18cff01ab31dfa66c8249b6584a.tar.gz | |
wma: fix invalid buffer size assumptions causing random overreads.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
| -rw-r--r-- | libavcodec/wma.h | 2 | ||||
| -rw-r--r-- | libavcodec/wmadec.c | 13 |
2 files changed, 11 insertions, 4 deletions
diff --git a/libavcodec/wma.h b/libavcodec/wma.h index 4acbf04bbf..d6f4880c14 100644 --- a/libavcodec/wma.h +++ b/libavcodec/wma.h @@ -124,7 +124,7 @@ typedef struct WMACodecContext { /* output buffer for one frame and the last for IMDCT windowing */ DECLARE_ALIGNED(32, float, frame_out)[MAX_CHANNELS][BLOCK_MAX_SIZE * 2]; /* last frame info */ - uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */ + uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + FF_INPUT_BUFFER_PADDING_SIZE]; /* padding added */ int last_bitoffset; int last_superframe_len; float noise_table[NOISE_TAB_SIZE]; diff --git a/libavcodec/wmadec.c b/libavcodec/wmadec.c index b9fc21fd3e..37feca1f7f 100644 --- a/libavcodec/wmadec.c +++ b/libavcodec/wmadec.c @@ -845,6 +845,12 @@ static int wma_decode_superframe(AVCodecContext *avctx, void *data, if (s->use_bit_reservoir) { bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3); + if (bit_offset > get_bits_left(&s->gb)) { + av_log(avctx, AV_LOG_ERROR, + "Invalid last frame bit offset %d > buf size %d (%d)\n", + bit_offset, get_bits_left(&s->gb), buf_size); + goto fail; + } if (s->last_superframe_len > 0) { // printf("skip=%d\n", s->last_bitoffset); @@ -861,9 +867,10 @@ static int wma_decode_superframe(AVCodecContext *avctx, void *data, if (len > 0) { *q++ = (get_bits)(&s->gb, len) << (8 - len); } + memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE); /* XXX: bit_offset bits into last frame */ - init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8); + init_get_bits(&s->gb, s->last_superframe, s->last_superframe_len * 8 + bit_offset); /* skip unused bits */ if (s->last_bitoffset > 0) skip_bits(&s->gb, s->last_bitoffset); @@ -877,9 +884,9 @@ static int wma_decode_superframe(AVCodecContext *avctx, void *data, /* read each frame starting from bit_offset */ pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3; - if (pos >= MAX_CODED_SUPERFRAME_SIZE * 8) + if (pos >= MAX_CODED_SUPERFRAME_SIZE * 8 || pos > buf_size * 8) return AVERROR_INVALIDDATA; - init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8); + init_get_bits(&s->gb, buf + (pos >> 3), (buf_size - (pos >> 3))*8); len = pos & 7; if (len > 0) skip_bits(&s->gb, len); |