Comment 3 for bug 1774431

This happens inside tirpc library:

#0 0x00007f86ab2e3254 in accept () from /lib64/libc.so.6
#1 0x00007f86ab5c1274 in rendezvous_request () from /lib64/libtirpc.so.3
#2 0x00007f86ab5bd6b8 in svc_getreq_common () from /lib64/libtirpc.so.3
#3 0x00007f86ab5bd947 in svc_getreq_poll () from /lib64/libtirpc.so.3
#4 0x00007f86ab5c016e in svc_run () from /lib64/libtirpc.so.3
#5 0x000055e6f0a3d6c7 in main (argc=2, argv=0x7ffc9afd7d18) at rquota_svc.c:538

The polled descriptors are:

rpc.rquot 21981 root 4u IPv4 80449159 0t0 UDP *:rquotad
rpc.rquot 21981 root 5u sock 0,9 0t0 80449162 protocol: TCP
rpc.rquot 21981 root 6u IPv6 80449165 0t0 UDP *:rquotad
rpc.rquot 21981 root 7u sock 0,9 0t0 80449168 protocol: TCPv6

One can use "/usr/sbin/rpc.rquotad -F" command to prevent from daemonization.

Fedora 27 is not affected, because it does not use tirpc there. I can also reproduce it on Fedora 29.

Either it's a bug in libtirpc-1.0.3-1.rc1.fc28.x86_64 that wants to accept raw sockets, or rpc.rquotad setups the tirpc service inappropriately. Maybe libtirpc maintainer will know more. rpc.rquotad code is in rquota_svc.c