Description of problem: As in title. See output of attached test program. Version-Release number of selected component (if applicable): glibc-2.5-18.fc6.i686 How reproducible: always Additional info: I've seen this problem on fully updated FC6, on F7 and CENTOS5 (this means RHEL5 is affected). Reproducible on both i386 and x86_64.
Created attachment 161256 [details] getnameinfo test program
User error. You should pass a->ai_addrlen as second argument to getnameinfo, sizeof (*a->ai_addr) is big enough for IPv4, but not for IPv6. On Linux sizeof (struct sockaddr) == sizeof (struct sockaddr_in) == 16, but sizeof (struct sockaddr_in6) == 28 and some other struct sockaddr_* are even bigger.