Bug 432020 – <sys-libs/glibc-2.21: /var/db/services.db causes infinite loop in getaddrinfo()

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Maxim Kammerer 2012-08-20 03:11:39 UTC]

glibc 2.15 provides /var/db/Makefile, which creates various databases for plaintext files using makedb:

  make -C /var/db

If /var/db/services.db is created, service name lookup using getaddrinfo() (but not getservbyname()) results in an infinite loop (full CPU load and no system calls).

This happens, e.g., if iptables is supplied named --sport / --dport parameters. An example program (to be attached) uses relevant code from iptables-1.4.13.

[Comment 1 Maxim Kammerer 2012-08-20 03:13:51 UTC]

Created attachment 321734 [details]
/var/db/services.db

[Comment 2 Maxim Kammerer 2012-08-20 03:16:10 UTC]

Created attachment 321736 [details]
getaddrinfo.c example

# ./getaddrinfo
getservbyname: 67
before
^C

[Comment 3 Maxim Kammerer 2012-08-20 03:21:28 UTC]

Created attachment 321738 [details]
emerge --info

This is a hardened system, but the problem appears both under hardened and regular kernel (in a chroot).

[Comment 4 SpanKY 2012-08-20 03:28:03 UTC]

nice test case -- doesn't really need iptables setup.  i've moved this upstream.

[Comment 5 SpanKY 2016-03-30 19:54:58 UTC]

glibc-2.21+ should be fixed, and that's stable now, so closing out