[FFmpeg-cvslog] avformat/mxfdec: Don't use wrong type of pointer
Andreas Rheinhardt
git at videolan.org
Fri Mar 19 01:53:28 EET 2021
ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Fri Mar 12 12:59:47 2021 +0100| [9224b1f6b3b554dfc5e941bf106bed06816b328c] | committer: Andreas Rheinhardt
avformat/mxfdec: Don't use wrong type of pointer
If one of the two results of a ternary conditional is a pointer to void,
the type of the whole conditional operator is a pointer to void, even
when the other possible result is not a pointer to void. This loophole
in the type system has allowed mxf_read_local_tags to have a pointer of
type pointer to MXFMetadataSet that actually points to an MXFContext.
Reviewed-by: Tomas Härdin <tjoppen at acc.umu.se>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9224b1f6b3b554dfc5e941bf106bed06816b328c
---
libavformat/mxfdec.c | 32 ++++++++++++++++++++------------
1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index bb00838a3f..8fea35b86b 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -2889,13 +2889,20 @@ static int mxf_metadataset_init(MXFMetadataSet *ctx, enum MXFMetadataSetType typ
static int mxf_read_local_tags(MXFContext *mxf, KLVPacket *klv, MXFMetadataReadFunc *read_child, int ctx_size, enum MXFMetadataSetType type)
{
AVIOContext *pb = mxf->fc->pb;
- MXFMetadataSet *ctx = ctx_size ? av_mallocz(ctx_size) : mxf;
uint64_t klv_end = avio_tell(pb) + klv->length;
+ MXFMetadataSet *meta;
+ void *ctx;
- if (!ctx)
- return AVERROR(ENOMEM);
- if (ctx_size)
- mxf_metadataset_init(ctx, type);
+ if (ctx_size) {
+ meta = av_mallocz(ctx_size);
+ if (!meta)
+ return AVERROR(ENOMEM);
+ ctx = meta;
+ mxf_metadataset_init(meta, type);
+ } else {
+ meta = NULL;
+ ctx = mxf;
+ }
while (avio_tell(pb) + 4 < klv_end && !avio_feof(pb)) {
int ret;
int tag = avio_rb16(pb);
@@ -2922,19 +2929,20 @@ static int mxf_read_local_tags(MXFContext *mxf, KLVPacket *klv, MXFMetadataReadF
}
}
}
- if (ctx_size && tag == 0x3C0A) {
- avio_read(pb, ctx->uid, 16);
+ if (meta && tag == 0x3C0A) {
+ avio_read(pb, meta->uid, 16);
} else if ((ret = read_child(ctx, pb, tag, size, uid, -1)) < 0) {
- if (ctx_size)
- mxf_free_metadataset(&ctx, 1);
+ if (meta) {
+ mxf_free_metadataset(&meta, 1);
+ }
return ret;
}
/* Accept the 64k local set limit being exceeded (Avid). Don't accept
* it extending past the end of the KLV though (zzuf5.mxf). */
if (avio_tell(pb) > klv_end) {
- if (ctx_size) {
- mxf_free_metadataset(&ctx, 1);
+ if (meta) {
+ mxf_free_metadataset(&meta, 1);
}
av_log(mxf->fc, AV_LOG_ERROR,
@@ -2944,7 +2952,7 @@ static int mxf_read_local_tags(MXFContext *mxf, KLVPacket *klv, MXFMetadataReadF
} else if (avio_tell(pb) <= next) /* only seek forward, else this can loop for a long time */
avio_seek(pb, next, SEEK_SET);
}
- return ctx_size ? mxf_add_metadata_set(mxf, &ctx) : 0;
+ return meta ? mxf_add_metadata_set(mxf, &meta) : 0;
}
/**
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