[FFmpeg-devel] [PATCH v2 05/14] h264_mp4toannexb: Add a comment about possible overread

Andreas Rheinhardt andreas.rheinhardt at gmail.com
Sun Dec 15 00:19:17 EET 2019

Before reading a 16bit size field during parsing of extradata, no check
is performed to make sure that said length field is actually contained
in the extradata. Given that this overread is not dangerous (the extradata
is supposed to be padded), only a comment for it has been added; the error
itself will be detected as part of the normal check for overreads.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
 libavcodec/h264_mp4toannexb_bsf.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libavcodec/h264_mp4toannexb_bsf.c b/libavcodec/h264_mp4toannexb_bsf.c
index b9c6b165af..f809c6b3ad 100644
--- a/libavcodec/h264_mp4toannexb_bsf.c
+++ b/libavcodec/h264_mp4toannexb_bsf.c
@@ -98,6 +98,7 @@ static int h264_extradata_to_annexb(AVBSFContext *ctx, const int padding)
     while (unit_nb--) {
         int err;
+        /* possible overread ok due to padding */
         unit_size   = bytestream2_get_be16u(gb);
         total_size += unit_size + 4;
         av_assert1(total_size <= INT_MAX - padding);

More information about the ffmpeg-devel mailing list