Red Hat Bugzilla – Bug 209881
nscd-2.4-11 segfaults
Last modified: 2008-08-02 19:40:33 EDT
+++ This bug was initially created as a clone of Bug #200963 +++ From Bug #200963 comment 10: -- Additional comment from Chris Jones on 2006-10-03 03:55 EST -- This is still a bug in FC5 with the following versions nscd-2.4-11 glibc-2.4-11 Oct 3 07:23:49 silver kernel: nscd[15245]: segfault at 00002aab40bff13e rip 00002aaaaeb9f025 rsp 0000000040c00100 error 4
What platform are you running on, Chris?
This was on a x86_64 host.
The above isn't sufficient to determine what the problem is, I certainly can't reproduce this on any of my FC5 boxes. So, can you: 1) attach your /etc/nsswitch.conf, so that it is clear what NSS services are in use 2) install glibc-debuginfo-2.4-11.x86_64.rpm and either run nscd under gdb and try to reproduce it, or ulimit -c unlimited before you run it and when it segfaults, get a backtrace where it crashed
I'm seeing this as well, also on x86_64 hosts using LDAP lookups. I'll attach our nsswitch.conf and a backtrace. We're currently using nscd-2.4-8, but I'll install nscd-2.4-11 and see if the problem persists.
Created attachment 139013 [details] nsswitch setup for machine with nscd crashes
Created attachment 139014 [details] gdb backtrace for segfaulted nscd.
Can you run nscd under LD_DEBUG=all LD_DEBUG_OUTPUT=/tmp/nscd.debug.out /usr/sbin/nscd ? Although the backtrace is incomplete, it still shows something that should never happen in nscd - /usr/sbin/nscd itself exports getaddrinfo symbol and all libraries calls to getaddrinfo should resolve to the nscd's copy rather than libc.so.6 (and, libc.so.6's getaddrinfo is the only one containing the __GI_getaddrinfo alias).
Actually, grepping through nss_ldap and openldap sources, I believe the #6 backtrace can't be from nscd itself and therefore it is unrelated to this bugreport. If nscd itself isn't segfaulting, you are seeing something else. My guess would be that you have too many nscd lookups and nscd tried to grow the cache, something that has been fixed recently in FC6 (glibc-2.5-2 and above) and RHEL4 testing glibc. That will be fixed in FC5 too later, as a workaround for that (and a proof that it you are actually seeing that bug) you can edit /etc/nscd.conf, change suggested-size hosts to some larger prime, like 16381, shut down nscd, rm -f /var/db/nscd/* and start nscd again.
Thanks, Jakub. My apologies--the core file I was given wasn't from nscd. I'll try the configuration change you suggested. -lars
Still waiting on details from the original reporter. Without them there is nothing to do here, so if they aren't added soon, I'll close this.
Created attachment 140708 [details] NSS Conf
Can you be a little more explicit about what you want me to provide (and what I need to do to get it)?
*ping*
*pong* Im still seeing segfaults a couple of times a week from nscd.
Jakub - in comment #10, you said you are still waiting for details from the original reporter. The original reporter should be considered to be Chris Jones. What details do you need from Chris Jones to proceed? Thanks in advance.
This looks like it might be a dup of Bug #190431 ...
Maybe related to Bug #154314 ?
Ok, so Bug #236530 seems to be related to this. I've tried starting nscd with 'LD_DEBUG=all LD_DEBUG_OUTPUT=/tmp/nscd.debug.out /usr/sbin/nscd' and it stops again. Just doing '/usr/sbin/nscd' works as expected however. Any ideas?
Created attachment 154137 [details] The output from the short lived nscd
FC5 is no longer supported. If you can reproduce it with F7 or rawhide, please reopen.