[FFmpeg-cvslog] avformat/id3v2: read_uslt() check for the amount read

[Michael Niedermayer]

ffmpeg | branch: release/5.1 | Michael Niedermayer <michael at niedermayer.cc> | Wed Mar 20 03:51:05 2024 +0100| [7fa625df70f38255657129d90e8cd60cdf2bc78f] | committer: Michael Niedermayer

avformat/id3v2: read_uslt() check for the amount read

Fixes: timeout
Fixes: 66783/clusterfuzz-testcase-minimized-ffmpeg_dem_GENH_fuzzer-5356884892647424

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit c0f4abe2aa0117a10fb651f2c1c030d4cd516081)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7fa625df70f38255657129d90e8cd60cdf2bc78f
---

 libavformat/id3v2.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/id3v2.c b/libavformat/id3v2.c
index cb31864045..e6c0385a58 100644
--- a/libavformat/id3v2.c
+++ b/libavformat/id3v2.c
@@ -366,7 +366,7 @@ static void read_uslt(AVFormatContext *s, AVIOContext *pb, int taglen,
     int encoding;
     int ok = 0;
 
-    if (taglen < 1)
+    if (taglen < 4)
         goto error;
 
     encoding = avio_r8(pb);