From bb46e9cc84675cb0bb342c246596435ebc56083e Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 19 Apr 2021 20:23:44 +0200 Subject: [PATCH] avformat/id3v2: Check end for overflow in id3v2_parse() Fixes: signed integer overflow: 9223372036840103978 + 67637280 cannot be represented in type 'long' Fixes: 33341/clusterfuzz-testcase-minimized-ffmpeg_dem_DSF_fuzzer-6408154041679872 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit efdb56450418933965dc6e27f0b1625d25e44a8c) Signed-off-by: Michael Niedermayer --- libavformat/id3v2.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/libavformat/id3v2.c b/libavformat/id3v2.c index 03f70cc765..cfe07091b1 100644 --- a/libavformat/id3v2.c +++ b/libavformat/id3v2.c @@ -818,7 +818,7 @@ static void id3v2_parse(AVIOContext *pb, AVDictionary **metadata, int isv34, unsync; unsigned tlen; char tag[5]; - int64_t next, end = avio_tell(pb) + len; + int64_t next, end = avio_tell(pb); int taghdrlen; const char *reason = NULL; AVIOContext pb_local; @@ -829,6 +829,10 @@ static void id3v2_parse(AVIOContext *pb, AVDictionary **metadata, unsigned char *uncompressed_buffer = NULL; av_unused int uncompressed_buffer_size = 0; + if (end > INT64_MAX - len - 10) + return; + end += len; + av_log(s, AV_LOG_DEBUG, "id3v2 ver:%d flags:%02X len:%d\n", version, flags, len); switch (version) {