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| author | Andreas Rheinhardt <andreas.rheinhardt@gmail.com> | 2020-05-27 19:09:14 +0200 |
|---|---|---|
| committer | Andreas Rheinhardt <andreas.rheinhardt@gmail.com> | 2020-06-15 04:46:05 +0200 |
| commit | 07eb039e047b68227b08428314314ff7b1273efa (patch) | |
| tree | d34c4920845a214701a0727e1f332200c3705d19 | |
| parent | 221e490d42bc1c20c61aee385d5bfe003a1a8c87 (diff) | |
| download | ffmpeg-07eb039e047b68227b08428314314ff7b1273efa.tar.gz | |
avcodec/hevc_mp4toannexb_bsf: Check NAL size against available input
The hevc_mp4toannexb bsf does not explicitly check whether a NAL unit
is so big that it extends beyond the end of the input packet; it does so
only implicitly by using the checked version of the bytestream2 API.
But this has downsides compared to real checks: It can lead to huge
allocations (up to 2GiB) even when the input packet is just a few bytes.
And furthermore it leads to uninitialized data being output.
So add a check to error out early if it happens.
Also check directly whether there is enough data for the length field.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
(cherry picked from commit ea1b71e82f5a1752d59d3bfb9704092a79eba6b5)
| -rw-r--r-- | libavcodec/hevc_mp4toannexb_bsf.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/libavcodec/hevc_mp4toannexb_bsf.c b/libavcodec/hevc_mp4toannexb_bsf.c index 30f733d775..477d86d9fd 100644 --- a/libavcodec/hevc_mp4toannexb_bsf.c +++ b/libavcodec/hevc_mp4toannexb_bsf.c @@ -141,10 +141,14 @@ static int hevc_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *out) int nalu_type; int is_irap, add_extradata, extra_size, prev_size; + if (bytestream2_get_bytes_left(&gb) < s->length_size) { + ret = AVERROR_INVALIDDATA; + goto fail; + } for (i = 0; i < s->length_size; i++) nalu_size = (nalu_size << 8) | bytestream2_get_byte(&gb); - if (nalu_size < 2) { + if (nalu_size < 2 || nalu_size > bytestream2_get_bytes_left(&gb)) { ret = AVERROR_INVALIDDATA; goto fail; } |