Bug 432020

Summary:	<sys-libs/glibc-2.21: /var/db/services.db causes infinite loop in getaddrinfo()
Product:	Gentoo Linux	Reporter:	Maxim Kammerer <mk>
Component:	[OLD] Core system	Assignee:	Gentoo Toolchain Maintainers <toolchain>
Status:	RESOLVED FIXED
Severity:	normal	CC:	ahudson.news, barzog, holger, leho
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	http://sourceware.org/bugzilla/show_bug.cgi?id=14498
See Also:	http://sourceware.org/bugzilla/show_bug.cgi?id=14498
Whiteboard:
Package list:		Runtime testing required:	---
Attachments:	/var/db/services.db getaddrinfo.c example emerge --info

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 gentoo-dev

2012-08-20 03:28:03 UTC

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

Comment 5 SpanKY gentoo-dev

2016-03-30 19:54:58 UTC

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