cupsd hangs when altering configuration

[michaelrsweet]

Version: 1.1.20
CUPS.org User: axel.privat.web

Using http://localhost:631 for administration purposes causes cupsd to chew up some 80 percent CPU time, thereby stopping any and all printing functionality. This is observed trying to:

• delete a printer
• add a printer
• change a printer's configuration
  The browser does not complete a request like:
  http://localhost:631/admin/?op=delete-printer&printer_name=epson&confirm=yes

Restarting cups via the init scripts is sufficient to resume 'normal' operation.
Attaching gdb to the hanging cupsd shows a very small backtrace only:
#0 0x44ce408d in time () from /lib/libc.so.6
#1 0x0805eac3 in SrvUrlCallback ()
#2 0x44c67c8b in __libc_start_main () from /lib/libc.so.6
#3 0x0804c861 in ?? ()

My configuration:

• Linux 2.4.23-grsec-1.9.13 on i686 AMD Athlon(tm) XP 1800+ AuthenticAMD Processor
• gcc version 3.3.2 20031022 (Gentoo Linux 3.3.2-r3, propolice)
• glibc-2.3.2

[michaelrsweet]

CUPS.org User: mike

What version of OpenSLP are you using?

Does the problem occur when you do not use SLP for browsing?

[michaelrsweet]

CUPS.org User: axel.privat.web

OpenSLP version 1.0.11
I have just figured out that I can completely circumvent the problem setting the ServerName to localhost in cupsd.conf.

Can I confirm/disproof somehow that the problem is e.g. DNS lookup related? Might the grsecurity kernel extension cause the trouble? Anything else I can provide to help you?

[michaelrsweet]

CUPS.org User: axel.privat.web

Sorry, forgot to answer the second part of your question:
I removed OpenSLP from my system and recompiled cups without
SLP support. If I do not set the ServerName to localhost
(e.g. by not specifying a ServerName at all), the problem persists.

I won't be in town from 21st to 28th of December and therefore
cannot check for mail.

Merry Christmas to y'all!

[michaelrsweet]

CUPS.org User: mike

I would suspect that the problem lies with the hostname lookups, then, and is unrelated to SLP at all.

[michaelrsweet]

CUPS.org User: axel.privat.web

Looks like it. I've fixed the lookup issues on the affected machine and cannot reproduce the error anymore. I suggest this bug report
may be closed.