Bug 62548

Summary: pause when su-ing from nobody with pam-0.75-18.7
Product: [Retired] Red Hat Linux Reporter: Steve Mellor <steveme>
Component: pamAssignee: Jindrich Novy <jnovy>
Status: CLOSED CURRENTRELEASE QA Contact: Aaron Brown <abrown>
Severity: medium Docs Contact:
Priority: medium    
Version: 7.1CC: pknirsch
Target Milestone: ---   
Target Release: ---   
Hardware: i686   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2004-10-03 19:15:20 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Steve Mellor 2002-04-02 14:12:49 UTC
Description of problem:

su hangs for approx 20 sec when su-ing from nobody.

no hang if pam_xauth.so is commented out of /etc/pam.d/su
no hang if you su from any other user than nobody


Version-Release number of selected component: pam-0.75-18.7

How reproducible: Always

Steps to Reproduce:

1. update pam to pam-0.75-18.7  (the fix for RHBA-2001:149-14)
2. from a root login: 'su - nobody'
3. su - <a user>

once the password is entered there is a 20 sec delay before the su command
completes. strace on the 'su' shows :

[snip]
read(3, "root:x:0:0:root:/root:/bin/bash\n"..., 4096) = 4096
close(3)                                = 0
munmap(0x40022000, 4096)                = 0
getgid32()                              = 99
getuid32()                              = 99
pipe([3, 4])                            = 0
pipe([5, 6])                            = 0
fork()                                  = 24264
close(3)                                = 0
close(6)                                = 0
close(4)                                = 0
read(5,

<20 seconds delay>

 "", 2048)                       = 0
--- SIGCHLD (Child exited) ---
close(5)                                = 0
wait4(24264, NULL, 0, NULL)             = 24264
fork()                                  = 24265
rt_sigprocmask(SIG_BLOCK, ~[], NULL, 8) = 0
rt_sigaction(SIGTERM, {0x80498c0, [], 0x4000000}, NULL, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [ALRM TERM], NULL, 8) = 0
wait4(-1,

Comment 1 Jindrich Novy 2004-10-03 19:15:20 UTC
[root@localhost root]#su - nobody
This account is currently not available.

Looks like there's no more possible to log in as nobody.