Module: libav Branch: release/9 Commit: 251b4655be73f4b5e86d3e81d61abb5787b1262b
Author: Anton Khirnov <[email protected]> Committer: Luca Barbato <[email protected]> Date: Sat Aug 24 21:30:46 2013 +0200 vcr1: add sanity checks Fixes invalid reads with corrupted files. Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind CC: [email protected] (cherry picked from commit 8aba7968dd604aae91ee42cbce0be3dad7dceb30) Signed-off-by: Luca Barbato <[email protected]> --- libavcodec/vcr1.c | 21 +++++++++++++++++++++ 1 files changed, 21 insertions(+), 0 deletions(-) diff --git a/libavcodec/vcr1.c b/libavcodec/vcr1.c index d0805a3..42ba787 100644 --- a/libavcodec/vcr1.c +++ b/libavcodec/vcr1.c @@ -50,6 +50,11 @@ 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; } @@ -85,9 +90,13 @@ 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++) { @@ -98,8 +107,12 @@ static int vcr1_decode_frame(AVCodecContext *avctx, void *data, uint8_t *cb = &a->picture.data[1][(y >> 2) * a->picture.linesize[1]]; uint8_t *cr = &a->picture.data[2][(y >> 2) * a->picture.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) { @@ -113,8 +126,12 @@ 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) { @@ -128,6 +145,7 @@ static int vcr1_decode_frame(AVCodecContext *avctx, void *data, luma[7] = offset += a->delta[bytestream[1] >> 4]; luma += 8; bytestream += 4; + buf_size -= 4; } } } @@ -136,6 +154,9 @@ 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 = { _______________________________________________ libav-commits mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-commits
