[FFmpeg-cvslog] avformat/rka: Fix 1/0 with bps=1

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Mon Feb 20 19:38:00 2023 +0100| [b3df7ca748bf28e41a6fcb6792b485d8eb04b36a] | committer: Michael Niedermayer

avformat/rka: Fix 1/0 with bps=1

Fixes: division by zero
Fixes: 55940/clusterfuzz-testcase-minimized-ffmpeg_IO_DEMUXER_fuzzer-6333107679920128

The decoder does not support bps=1 and i have no such sample so it is not
known if this duration is correct. Alternatively we could error out on all
bps we currently do not support on the decoder side or not set duration.

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=b3df7ca748bf28e41a6fcb6792b485d8eb04b36a
---

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

diff --git a/libavformat/rka.c b/libavformat/rka.c
index cc55480345..39e5b3bce1 100644
--- a/libavformat/rka.c
+++ b/libavformat/rka.c
@@ -114,7 +114,7 @@ static int rka_read_header(AVFormatContext *s)
     par->ch_layout.nb_channels = channels;
     par->sample_rate = samplerate;
     par->bits_per_raw_sample = bps;
-    st->duration = nb_samples / (channels * (bps >> 3));
+    st->duration = 8LL*nb_samples / (channels * bps);
 
     if (s->pb->seekable & AVIO_SEEKABLE_NORMAL)
         ff_ape_parse_tag(s);