edquota crashes when used with libnss-db

[Ballock]

Binary package hint: libnss-db

Hello,

This is from Ubuntu Lucid, libnss-db 2.2.3pre1-3.1ubuntu4.

I am using nss-updatedb to get user information from LDAP and I am using nsswitch.conf with the 'db' backend. Everything was fine until I tried to setup quota on one of the machines. edquota segfaults. I changed the backend to 'ldap', and this worked so this showed that the problem is in libnss-db.

LD_PRELOAD=/lib/libpthread.so.0 gdb --args edquota -f /home -u bt
GNU gdb (GDB) 7.1-ubuntu
[...]
(gdb) run
Starting program: /usr/sbin/edquota -f /home -u bt
[Thread debugging using libthread_db enabled]

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff81ff8f0 in dirname ()
(gdb) bt
#0 0x00007ffff81ff8f0 in dirname ()
#1 0x00007ffff741b893 in ?? () from /usr/lib/libnss_db.so.2
#2 0x00007ffff741a21a in ?? () from /usr/lib/libnss_db.so.2
#3 0x00007ffff741a59b in _nss_db_getpwnam_r () from /usr/lib/libnss_db.so.2
#4 0x00007ffff78d449d in getpwnam_r () from /lib/libc.so.6
#5 0x00007ffff78d3e80 in getpwnam () from /lib/libc.so.6
#6 0x00007ffff7ff4fec in ?? ()
#7 0x00007ffff7ff0a4c in main ()

This was not very communicative, so I recompiled the package without dh_strip, and tried the same:
LD_PRELOAD=/lib/libpthread.so.0 gdb --args edquota -f /home -u bt
[...]
(gdb) run
Starting program: /usr/sbin/edquota -f /home -u bt
[Thread debugging using libthread_db enabled]

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff81ff8f0 in dirname ()
(gdb) bt
#0 0x00007ffff81ff8f0 in dirname ()
#1 0x00007ffff741b893 in internal_setent (
    file=0x7ffff741ba87 "/var/lib/misc/passwd.db", dbp=0x7ffff761d290,
    dbenvp=0x7ffff761d288) at db-open.c:66
#2 0x00007ffff741a21a in lookup (key=0x7fffffffe4a0, result=0x7ffff7baace0,
    buffer=0x7ffff820a000, buflen=1024, errnop=0x7ffff7fd06a8) at db-XXX.c:116
#3 0x00007ffff741a59b in _nss_db_getpwnam_r (name=0x7fffffffe972 "bt",
    result=0x7ffff7baace0, buffer=0x7ffff820a000 "qatools", buflen=1024,
    errnop=0x7ffff7fd06a8) at files-pwd.c:33
#4 0x00007ffff78d449d in getpwnam_r () from /lib/libc.so.6
#5 0x00007ffff78d3e80 in getpwnam () from /lib/libc.so.6
#6 0x00007ffff7ff4fec in ?? ()
#7 0x00007ffff7ff0a4c in main ()

Well, I am no developer, so I don't give a clue about why this fails.

Could somebody please fix it?

Best regards,
Boleslaw Tokarski

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[jablko (ms419)]

I think that this is the same bug described here:

  * https://bugzilla.redhat.com/show_bug.cgi?id=703567
  * http://sourceforge.net/tracker/index.php?func=detail&aid=3300978&group_id=18136&atid=118136

Apparently a fix was committed upstream in version 4.00_pre2, so I guess this bug is fixed in Ubuntu release 12.04 and higher

http://lists.fedoraproject.org/pipermail/scm-commits/2011-May/604785.html

[Ballock (ballock)]

Hello, jabłko,

Thanks for the details. The problem was found on our Lucid build-servers, so this is still a problem there.

However, knowing that the problem is fixed in some particular version lets us backport the particular package.

I am not sure if anyone will bother with backporting the fix to lucid?

Cheers,
Ballock