avformat/aviobuf: Fix signed integer overflow in avio_seek()
authorVitaly Buka <vitalybuka-at-google.com@ffmpeg.org>
Sun, 20 Aug 2017 18:56:47 +0000 (11:56 -0700)
committerMichael Niedermayer <michael@niedermayer.cc>
Sun, 17 Sep 2017 10:21:32 +0000 (12:21 +0200)
Signed integer overflow is undefined behavior.
Detected with clang and -fsanitize=signed-integer-overflow

Signed-off-by: Vitaly Buka <vitalybuka@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit eca2a49716ae1f42804dd3545da2f740edf03250)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavformat/aviobuf.c

index 134d627..02f6d38 100644 (file)
@@ -249,6 +249,8 @@ int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
         offset1 = pos + (s->buf_ptr - s->buffer);
         if (offset == 0)
             return offset1;
+        if (offset > INT64_MAX - offset1)
+            return AVERROR(EINVAL);
         offset += offset1;
     }
     if (offset < 0)