[FFmpeg-cvslog] avformat/tty: Check avio_size()

[Michael Niedermayer]

ffmpeg | branch: release/4.3 | Michael Niedermayer <michael at niedermayer.cc> | Thu Jul 11 21:05:20 2024 +0200| [7c6f9c872fe42238439b79aaf27c38648caabc96] | committer: Michael Niedermayer

avformat/tty: Check avio_size()

Fixes: CID1220824 Overflowed constant

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 41745e550a0274571bd9fbfb12b36ff1743d4e9c)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7c6f9c872fe42238439b79aaf27c38648caabc96
---

 libavformat/tty.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/libavformat/tty.c b/libavformat/tty.c
index aed5c888c3..b47f874c60 100644
--- a/libavformat/tty.c
+++ b/libavformat/tty.c
@@ -122,13 +122,16 @@ static int read_header(AVFormatContext *avctx)
     s->chars_per_frame = FFMAX(av_q2d(st->time_base)*s->chars_per_frame, 1);
 
     if (avctx->pb->seekable & AVIO_SEEKABLE_NORMAL) {
-        s->fsize = avio_size(avctx->pb);
-        st->duration = (s->fsize + s->chars_per_frame - 1) / s->chars_per_frame;
+        int64_t fsize = avio_size(avctx->pb);
+        if (fsize > 0) {
+            s->fsize = fsize;
+            st->duration = (s->fsize + s->chars_per_frame - 1) / s->chars_per_frame;
 
-        if (ff_sauce_read(avctx, &s->fsize, 0, 0) < 0)
-            efi_read(avctx, s->fsize - 51);
+            if (ff_sauce_read(avctx, &s->fsize, 0, 0) < 0)
+                efi_read(avctx, s->fsize - 51);
 
-        avio_seek(avctx->pb, 0, SEEK_SET);
+            avio_seek(avctx->pb, 0, SEEK_SET);
+        }
     }
 
 fail: