[FFmpeg-cvslog] avformat/dhav: Use 64bit seek_back

[Michael Niedermayer]

ffmpeg | branch: release/5.0 | Michael Niedermayer <michael at niedermayer.cc> | Sat Sep 17 21:54:31 2022 +0200| [ad15735158c2f127a05ed4b8d9d1dbf785bd76fe] | committer: Michael Niedermayer

avformat/dhav: Use 64bit seek_back

Fixes: negation of -2147483648 cannot be represented in type 'int'; cast to an unsigned type to negate this value to itself
Fixes: 50993/clusterfuzz-testcase-minimized-ffmpeg_dem_DHAV_fuzzer-6604736532447232

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 10453f5192869b63b071aee3962ae2c712f9bfd3)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ad15735158c2f127a05ed4b8d9d1dbf785bd76fe
---

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

diff --git a/libavformat/dhav.c b/libavformat/dhav.c
index 6c1cdde32c..33b473d537 100644
--- a/libavformat/dhav.c
+++ b/libavformat/dhav.c
@@ -242,7 +242,7 @@ static int64_t get_duration(AVFormatContext *s)
     avio_seek(s->pb, avio_size(s->pb) - 8, SEEK_SET);
     while (avio_tell(s->pb) > 12 && max_interations--) {
         if (avio_rl32(s->pb) == MKTAG('d','h','a','v')) {
-            int seek_back = avio_rl32(s->pb);
+            int64_t seek_back = avio_rl32(s->pb);
 
             avio_seek(s->pb, -seek_back, SEEK_CUR);
             read_chunk(s);