diff options
author | Anton Khirnov <anton@khirnov.net> | 2013-08-24 21:30:46 +0200 |
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committer | Anton Khirnov <anton@khirnov.net> | 2013-09-02 19:27:33 +0200 |
commit | 8aba7968dd604aae91ee42cbce0be3dad7dceb30 (patch) | |
tree | 11079c12fe95134435d389721d3a870db37d509f /libavcodec | |
parent | 21ffd4101167ef4dcc271132f950e0f9ec58a7bd (diff) | |
download | ffmpeg-8aba7968dd604aae91ee42cbce0be3dad7dceb30.tar.gz |
vcr1: add sanity checks
Fixes invalid reads with corrupted files.
Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Diffstat (limited to 'libavcodec')
-rw-r--r-- | libavcodec/vcr1.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/libavcodec/vcr1.c b/libavcodec/vcr1.c index c4b817ead8..dd8bcf0ccf 100644 --- a/libavcodec/vcr1.c +++ b/libavcodec/vcr1.c @@ -37,6 +37,11 @@ static av_cold int vcr1_decode_init(AVCodecContext *avctx) { avctx->pix_fmt = AV_PIX_FMT_YUV410P; + if (avctx->width & 7) { + av_log(avctx, AV_LOG_ERROR, "Width %d is not divisble by 8.\n", avctx->width); + return AVERROR_INVALIDDATA; + } + return 0; } @@ -57,9 +62,13 @@ static int vcr1_decode_frame(AVCodecContext *avctx, void *data, p->pict_type = AV_PICTURE_TYPE_I; p->key_frame = 1; + if (buf_size < 32) + goto packet_small; + for (i = 0; i < 16; i++) { a->delta[i] = *bytestream++; bytestream++; + buf_size--; } for (y = 0; y < avctx->height; y++) { @@ -70,8 +79,12 @@ static int vcr1_decode_frame(AVCodecContext *avctx, void *data, uint8_t *cb = &p->data[1][(y >> 2) * p->linesize[1]]; uint8_t *cr = &p->data[2][(y >> 2) * p->linesize[2]]; + if (buf_size < 4 + avctx->width) + goto packet_small; + for (i = 0; i < 4; i++) a->offset[i] = *bytestream++; + buf_size -= 4; offset = a->offset[0] - a->delta[bytestream[2] & 0xF]; for (x = 0; x < avctx->width; x += 4) { @@ -85,8 +98,12 @@ static int vcr1_decode_frame(AVCodecContext *avctx, void *data, *cr++ = bytestream[1]; bytestream += 4; + buf_size -= 4; } } else { + if (buf_size < avctx->width / 2) + goto packet_small; + offset = a->offset[y & 3] - a->delta[bytestream[2] & 0xF]; for (x = 0; x < avctx->width; x += 8) { @@ -100,6 +117,7 @@ static int vcr1_decode_frame(AVCodecContext *avctx, void *data, luma[7] = offset += a->delta[bytestream[1] >> 4]; luma += 8; bytestream += 4; + buf_size -= 4; } } } @@ -107,6 +125,9 @@ static int vcr1_decode_frame(AVCodecContext *avctx, void *data, *got_frame = 1; return buf_size; +packet_small: + av_log(avctx, AV_LOG_ERROR, "Input packet too small.\n"); + return AVERROR_INVALIDDATA; } AVCodec ff_vcr1_decoder = { |