The threshold of 5 is arbitrary, both smaller and larger should work fine Fixes: Stack overflow Fixes: 50603/clusterfuzz-testcase-minimized-ffmpeg_dem_ASF_O_fuzzer-6049302564175872
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> --- libavformat/asfdec_o.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/libavformat/asfdec_o.c b/libavformat/asfdec_o.c index 907be6de04f..48b7d17322d 100644 --- a/libavformat/asfdec_o.c +++ b/libavformat/asfdec_o.c @@ -109,6 +109,7 @@ typedef struct ASFContext { int64_t data_offset; int64_t first_packet_offset; // packet offset int64_t unknown_offset; // for top level header objects or subobjects without specified behavior + int in_asf_read_unknown; // ASF file must not contain more than 128 streams according to the specification ASFStream *asf_st[ASF_MAX_STREAMS]; @@ -173,7 +174,7 @@ static int asf_read_unknown(AVFormatContext *s, const GUIDParseTable *g) uint64_t size = avio_rl64(pb); int ret; - if (size > INT64_MAX) + if (size > INT64_MAX || asf->in_asf_read_unknown > 5) return AVERROR_INVALIDDATA; if (asf->is_header) @@ -182,8 +183,11 @@ static int asf_read_unknown(AVFormatContext *s, const GUIDParseTable *g) if (!g->is_subobject) { if (!(ret = strcmp(g->name, "Header Extension"))) avio_skip(pb, 22); // skip reserved fields and Data Size - if ((ret = detect_unknown_subobject(s, asf->unknown_offset, - asf->unknown_size)) < 0) + asf->in_asf_read_unknown ++; + ret = detect_unknown_subobject(s, asf->unknown_offset, + asf->unknown_size); + asf->in_asf_read_unknown --; + if (ret < 0) return ret; } else { if (size < 24) { -- 2.17.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".