[FFmpeg-cvslog] avformat/flvdec: Check data before casting

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Jun  8 18:09:55 2021 +0200| [1e24da5cfe1cec70e322b93578227465f325936e] | committer: Michael Niedermayer

avformat/flvdec: Check data before casting

Fixes: -nan is outside the range of representable values of type 'long'
Fixes: signed integer overflow: 1000 * -9223372036854775808 cannot be represented in type 'long'
Fixes: 34890/clusterfuzz-testcase-minimized-ffmpeg_dem_FLV_fuzzer-5334208657620992

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1e24da5cfe1cec70e322b93578227465f325936e
---

 libavformat/flvdec.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c
index 6bd6c8c944..60d1a5c654 100644
--- a/libavformat/flvdec.c
+++ b/libavformat/flvdec.c
@@ -682,7 +682,11 @@ static int amf_parse_object(AVFormatContext *s, AVStream *astream,
             av_dict_set(&s->metadata, key, str_val, 0);
         } else if (amf_type == AMF_DATA_TYPE_STRING) {
             av_dict_set(&s->metadata, key, str_val, 0);
-        } else if (amf_type == AMF_DATA_TYPE_DATE) {
+        } else if (   amf_type == AMF_DATA_TYPE_DATE
+                   && isfinite(date.milliseconds)
+                   && date.milliseconds > INT64_MIN/1000
+                   && date.milliseconds < INT64_MAX/1000
+                  ) {
             // timezone is ignored, since there is no easy way to offset the UTC
             // timestamp into the specified timezone
             avpriv_dict_set_timestamp(&s->metadata, key, 1000 * (int64_t)date.milliseconds);