[Pkg-shadow-devel] Bug#523251: login: sudo su - randomly logs out after immediate key press

[Greg Cockburn]

Package: login
Version: 1:4.1.1-6
Severity: important


When invoking "sudo su -" I sometimes get immediately logged out back to the unprivileged user.

I have narrowed it down to something with "-su" process that gets created.
I don't seem to be able to recreate this for just a normal "su -", but the bug is not consistently reproducible.

I can somewhat consistently reproduce this bug on 4 systems that were all upgraded to Lenny from Etch.

Seems to happen about 50% of the times I "sudo su -".

Here is a strace from a "-su" process that had the issue.

Process 10609 attached - interrupt to quit
read(0, 0xbf92fa2f, 1)                  = -1 EIO (Input/output error)
rt_sigprocmask(SIG_BLOCK, [INT], [], 8) = 0
ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, {B38400 opost isig -icanon -echo ...}) = 0
ioctl(0, SNDCTL_TMR_STOP or TCSETSW, {B38400 opost isig icanon echo ...}) = 0
ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, {B38400 opost isig icanon echo ...}) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigaction(SIGINT, {0x8091fd0, [], 0}, {0x80c91d0, [], 0}, 8) = 0
rt_sigaction(SIGTERM, {SIG_IGN}, {SIG_IGN}, 8) = 0
rt_sigaction(SIGQUIT, {SIG_IGN}, {SIG_IGN}, 8) = 0
rt_sigaction(SIGALRM, {0x8091d90, [HUP INT ILL TRAP ABRT BUS FPE USR1 SEGV USR2 PIPE ALRM TERM XCPU XFSZ VTALRM SYS], 0}, {0x80c91d0, [], 0}, 8) = 0
rt_sigaction(SIGTSTP, {SIG_IGN}, {SIG_IGN}, 8) = 0
rt_sigaction(SIGTTOU, {SIG_IGN}, {SIG_IGN}, 8) = 0
rt_sigaction(SIGTTIN, {SIG_IGN}, {SIG_IGN}, 8) = 0
rt_sigaction(SIGWINCH, {0x8091c10, [], 0}, {0x80c9190, [], SA_RESTART}, 8) = 0
rt_sigaction(SIGINT, {0x8091fd0, [], 0}, {0x8091fd0, [], 0}, 8) = 0
write(2, "logout\n"..., 7)              = 7
open("/root/.bash_logout", O_RDONLY|O_LARGEFILE) = -1 ENOENT (No such file or directory)
open("/etc/bash.bash_logout", O_RDONLY|O_LARGEFILE) = -1 ENOENT (No such file or directory)
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigaction(SIGINT, {0x8091fd0, [], 0}, {0x8091fd0, [], 0}, 8) = 0
rt_sigprocmask(SIG_BLOCK, [CHLD TSTP TTIN TTOU], [], 8) = 0
ioctl(255, TIOCSPGRP, [10608])          = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
setpgid(0, 10608)                       = 0
exit_group(0)                           = ?
Process 10609 detached


-- System Information:
Debian Release: 5.0
  APT prefers proposed-updates
  APT policy: (500, 'proposed-updates'), (500, 'stable')
Architecture: i386 (i686)

Kernel: Linux 2.6.26-2-686 (SMP w/1 CPU core)
Locale: LANG=en_AU, LC_CTYPE=en_AU (charmap=ISO-8859-1)
Shell: /bin/sh linked to /bin/bash

Versions of packages login depends on:
ii  libc6                     2.7-18         GNU C Library: Shared libraries
ii  libpam-modules            1.0.1-5+lenny1 Pluggable Authentication Modules f
ii  libpam-runtime            1.0.1-5+lenny1 Runtime support for the PAM librar
ii  libpam0g                  1.0.1-5+lenny1 Pluggable Authentication Modules l

login recommends no packages.

login suggests no packages.

-- no debconf information