avformat/aviobuf: Fix signed integer overflow in avio_seek()

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 eca2a49716)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Vitaly Buka 2017-08-20 11:56:47 -07:00 committed by Michael Niedermayer
parent c889041352
commit 9739a269fb

View File

@ -251,6 +251,8 @@ 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)