dnsmasq spins at 100% cpu trying to receive socket messages via stdin

[James Hunt]

dnsmasq is spinning at 100% CPU. This also causes networking to fail. Problem seems to be that it is calling recvmsg(STDIN_FILENO, ...) which is totally invalid. See attached strace log.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: dnsmasq-base 2.70-1
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.2-0ubuntu2
Architecture: amd64
CurrentDesktop: Unity
Date: Thu May 8 10:33:54 2014
InstallationDate: Installed on 2014-05-06 (1 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Alpha amd64 (20140505)
SourcePackage: dnsmasq
UpgradeStatus: No upgrade log present (probably fresh install)