CVE-2015-5237: Integer overflow in protobuf serialization (currently minor)

[Florian Weimer <fweimer () redhat com>]

https://github.com/google/protobuf/issues/760

This is currently not intended to be addressed upstream, which is a bit
disappointing.  It's true that this issue does not have much exposure
right now, but in a couple of years, the message sizes involved will not
seem so gigantic anymore.  And as explained in the bug report, fixing
this will be difficult because it involves updating generated code; it
won't be a simple library update.

-- 
Florian Weimer / Red Hat Product Security