This commit closes the last hole in the system of checks for a
known-length file ending too early: Now an error message is emitted
in case the file ends directly after an EBML element.
Furthermore, this commit adds a check and a corresponding warning
whether there is data beyond the Matroska segment (only reasonable for
known-length segments). If everything looks alright, then parsing is
stopped as soon as EOF is reached (in contrast, the earlier code would
always call matroska_resync at the end).
Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com>
---
libavformat/matroskadec.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index fdd6c4b86b..f769543b4a 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -1183,10 +1183,15 @@ static int ebml_parse(MatroskaDemuxContext *matroska,
if (matroska->is_live)
// in live mode, finish parsing if EOF is reached.
return 1;
- if (level && level->length == EBML_UNKNOWN_LENGTH && pos ==
avio_tell(pb)) {
- // Unknown-length levels automatically end at EOF.
- matroska->num_levels--;
- return LEVEL_ENDED;
+ if (level && pos == avio_tell(pb)) {
+ if (level->length == EBML_UNKNOWN_LENGTH) {
+ // Unknown-length levels automatically end at EOF.
+ matroska->num_levels--;
+ return LEVEL_ENDED;
+ } else {
+ av_log(matroska->ctx, AV_LOG_ERROR, "File ended
prematurely "
+ "at pos. %"PRIu64" (0x%"PRIx64")\n", pos, pos);
+ }
}
}
return res;
@@ -3614,6 +3619,14 @@ static int matroska_parse_cluster(MatroskaDemuxContext
*matroska)
ebml_free(matroska_blockgroup, block);
memset(block, 0, sizeof(*block));
} else if (!matroska->num_levels) {
+ if (!avio_feof(matroska->ctx->pb)) {
+ avio_r8(matroska->ctx->pb);
+ if (!avio_feof(matroska->ctx->pb)) {
+ av_log(matroska->ctx, AV_LOG_WARNING, "File extends beyond "
+ "end of segment.\n");
+ return AVERROR_INVALIDDATA;
+ }
+ }
matroska->done = 1;
return AVERROR_EOF;
}
@@ -3634,7 +3647,7 @@ static int matroska_read_packet(AVFormatContext *s,
AVPacket *pkt)
while (matroska_deliver_packet(matroska, pkt)) {
if (matroska->done)
return (ret < 0) ? ret : AVERROR_EOF;
- if (matroska_parse_cluster(matroska) < 0)
+ if (matroska_parse_cluster(matroska) < 0 && !matroska->done)
ret = matroska_resync(matroska, matroska->resync_pos);
}
--
2.21.0
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