Re: Problem with "su -" and kernels 2.4.3-ac11 and higher

Lukasz Trabinski
2001-04-23T16:04:33Z

In article <20010422102234.A1093@ulthar.internal.mclure.org> you wrote:
> I'm having a problem with "su -" on ac11/ac12. ac5 doesn't show the
> problem.
> The problem is easy to reproduce - go to a console, log in as root, do an
> "su -" (this will succeed) and then another "su -". The second "su -"
> should hang - ps shows it started bash and that the bash process is
> sleeping. You need to "kill -9" the bash to get your prompt back.

> Distribution is Red Hat 7.1, running on an Athlon Thunderbird 900MHz on a
> MSI K7T Turbo R motherboard.

I have tested it on 2.4.4pre6, here is result:

[root@lt /root]# su - test

[root@lt /root]# ps xaf
1372 tty1 S 0:00 login -- root
1373 tty1 S 0:00 \_ -bash
1819 tty1 S 0:00 \_ su - test
1820 tty1 S 0:00 \_ -bash
1846 tty1 T 0:00 \_ stty erase ?

Last 10 lines from gdb su

Loaded symbols for /lib/security/pam_env.so
Reading symbols from /lib/security/pam_unix.so...done.
Loaded symbols for /lib/security/pam_unix.so
Reading symbols from /lib/security/pam_cracklib.so...done.
Loaded symbols for /lib/security/pam_cracklib.so
Reading symbols from /usr/lib/libcrack.so.2...done.
Loaded symbols for /usr/lib/libcrack.so.2
Reading symbols from /lib/security/pam_limits.so...done.
Loaded symbols for /lib/security/pam_limits.so
0x401156c9 in __wait4 () from /lib/libc.so.6
(gdb)

but:

[lukasz@lt lukasz]$ su -
Password:
[root@lt /root]#

It's looks OK :)

[lukasz@lt lukasz]$ su --version
su (GNU sh-utils) 2.0

[lukasz@lt lukasz]$ bash --version
GNU bash, version 2.04.21(1)-release (i386-redhat-linux-gnu)
Copyright 1999 Free Software Foundation, Inc.

[lukasz@lt lukasz]$ stty --version
stty (GNU sh-utils) 2.0

Kernel 2.4.4-pre6, 2.2.2-10, 0.74-22 - RedHat 7.1
AMD-K6 300 Mhz,

--
*[ Łukasz Trąbiński ]*
SysAdmin @wsisiz.edu.pl