[FFmpeg-cvslog] avformat/matroskadec: Properly check return values
Andreas Rheinhardt
git at videolan.org
Tue Jun 25 04:32:05 EEST 2019
ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Fri May 17 00:29:54 2019 +0200| [a27e5398e2d0e8af7eaa35001ea920d717fe9e38] | committer: James Almer
avformat/matroskadec: Properly check return values
Up until now, webm_dash_manifest_cues used the return values of
ebml_read_num and ebml_read_length without checking for errors,
i.e. return values < 0. This has been changed.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a27e5398e2d0e8af7eaa35001ea920d717fe9e38
---
libavformat/matroskadec.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 996bddf1c1..0e9938b65e 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -3864,12 +3864,17 @@ static int webm_dash_manifest_cues(AVFormatContext *s, int64_t init_range)
cues_start = seekhead[i].pos + matroska->segment_start;
if (avio_seek(matroska->ctx->pb, cues_start, SEEK_SET) == cues_start) {
// cues_end is computed as cues_start + cues_length + length of the
- // Cues element ID + EBML length of the Cues element. cues_end is
- // inclusive and the above sum is reduced by 1.
- uint64_t cues_length = 0, cues_id = 0, bytes_read = 0;
- bytes_read += ebml_read_num(matroska, matroska->ctx->pb, 4, &cues_id);
- bytes_read += ebml_read_length(matroska, matroska->ctx->pb, &cues_length);
- cues_end = cues_start + cues_length + bytes_read - 1;
+ // Cues element ID (i.e. 4) + EBML length of the Cues element.
+ // cues_end is inclusive and the above sum is reduced by 1.
+ uint64_t cues_length, cues_id;
+ int bytes_read;
+ bytes_read = ebml_read_num (matroska, matroska->ctx->pb, 4, &cues_id);
+ if (bytes_read < 0 || cues_id != (MATROSKA_ID_CUES & 0xfffffff))
+ return bytes_read < 0 ? bytes_read : AVERROR_INVALIDDATA;
+ bytes_read = ebml_read_length(matroska, matroska->ctx->pb, &cues_length);
+ if (bytes_read < 0)
+ return bytes_read;
+ cues_end = cues_start + 4 + bytes_read + cues_length - 1;
}
avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
if (cues_start == -1 || cues_end == -1) return -1;
More information about the ffmpeg-cvslog
mailing list