[FFmpeg-devel] [PATCH 6/9] avformat/rmdec: Fix memleaks upon read_header failure
Andreas Rheinhardt
andreas.rheinhardt at gmail.com
Tue Jul 21 05:12:12 EEST 2020
For both the RealMedia as well as the IVR demuxer (which share the same
context) each AVStream's priv_data contains an AVPacket that might
contain data (even when reading the header) and therefore needs to be
unreferenced. Up until now, this has not always been done:
The RealMedia demuxer didn't do it when allocating a new stream's
priv_data failed although there might other streams with packets to
unreference. (The reason for this was that until recently rm_read_close()
couldn't handle an AVStream without priv_data, so one had to choose
between a potential crash and a memleak.)
The IVR demuxer meanwhile never ever called read_close so that the data
already contained in packets leaks upon error.
This patch fixes both demuxers by setting the AVFMT_HEADER_CLEANUP flag,
thereby ensuring that rm_read_close() is always called when reading the
header fails. This also allows to remove several "goto fail" in
rm_read_header().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
libavformat/rmdec.c | 20 +++++++-------------
1 file changed, 7 insertions(+), 13 deletions(-)
diff --git a/libavformat/rmdec.c b/libavformat/rmdec.c
index 72b8dba741..c88f41c121 100644
--- a/libavformat/rmdec.c
+++ b/libavformat/rmdec.c
@@ -66,8 +66,6 @@ typedef struct RMDemuxContext {
int data_end;
} RMDemuxContext;
-static int rm_read_close(AVFormatContext *s);
-
static inline void get_strl(AVIOContext *pb, char *buf, int buf_size, int len)
{
int read = avio_get_str(pb, len, buf, buf_size);
@@ -557,16 +555,15 @@ static int rm_read_header(AVFormatContext *s)
avio_skip(pb, tag_size - 8);
for(;;) {
- ret = AVERROR_INVALIDDATA;
if (avio_feof(pb))
- goto fail;
+ return AVERROR_INVALIDDATA;
tag = avio_rl32(pb);
tag_size = avio_rb32(pb);
avio_rb16(pb);
av_log(s, AV_LOG_TRACE, "tag=%s size=%d\n",
av_fourcc2str(tag), tag_size);
if (tag_size < 10 && tag != MKTAG('D', 'A', 'T', 'A'))
- goto fail;
+ return AVERROR_INVALIDDATA;
switch(tag) {
case MKTAG('P', 'R', 'O', 'P'):
/* file header */
@@ -589,8 +586,7 @@ static int rm_read_header(AVFormatContext *s)
case MKTAG('M', 'D', 'P', 'R'):
st = avformat_new_stream(s, NULL);
if (!st) {
- ret = AVERROR(ENOMEM);
- goto fail;
+ return AVERROR(ENOMEM);
}
st->id = avio_rb16(pb);
avio_rb32(pb); /* max bit rate */
@@ -619,14 +615,14 @@ static int rm_read_header(AVFormatContext *s)
if (v == MKBETAG('M', 'L', 'T', 'I')) {
ret = rm_read_multi(s, s->pb, st, mime);
if (ret < 0)
- goto fail;
+ return ret;
avio_seek(pb, codec_pos + size, SEEK_SET);
} else {
avio_skip(pb, -4);
ret = ff_rm_read_mdpr_codecdata(s, s->pb, st, st->priv_data,
size, mime);
if (ret < 0)
- goto fail;
+ return ret;
}
break;
@@ -654,10 +650,6 @@ static int rm_read_header(AVFormatContext *s)
}
return 0;
-
-fail:
- rm_read_close(s);
- return ret;
}
static int get_num(AVIOContext *pb, int *len)
@@ -1141,6 +1133,7 @@ static int rm_read_seek(AVFormatContext *s, int stream_index,
AVInputFormat ff_rm_demuxer = {
.name = "rm",
.long_name = NULL_IF_CONFIG_SMALL("RealMedia"),
+ .flags = AVFMT_HEADER_CLEANUP,
.priv_data_size = sizeof(RMDemuxContext),
.read_probe = rm_probe,
.read_header = rm_read_header,
@@ -1393,6 +1386,7 @@ static int ivr_read_packet(AVFormatContext *s, AVPacket *pkt)
AVInputFormat ff_ivr_demuxer = {
.name = "ivr",
.long_name = NULL_IF_CONFIG_SMALL("IVR (Internet Video Recording)"),
+ .flags = AVFMT_HEADER_CLEANUP,
.priv_data_size = sizeof(RMDemuxContext),
.read_probe = ivr_probe,
.read_header = ivr_read_header,
--
2.20.1
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