Your message dated Sat, 10 Apr 2010 15:25:38 +0200
with message-id <20100410132538.ga13...@patate.is-a-geek.org>
and subject line Re: Bug#528608: xdm crashes with a nonexisting homedir, before
running pam_mkhomedir
has caused the Debian Bug report #528608,
regarding xdm crashes with a nonexisting homedir, before running pam_mkhomedir
to be marked as done.
This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.
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--
528608: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=528608
Debian Bug Tracking System
Contact ow...@bugs.debian.org with problems
--- Begin Message ---
Package: xdm
Version: 1:1.1.8-5
Severity: normal
xdm reproducibly crashes when the user's home directory does not exist,
before actually doing any pam session handling - so that pam_mkhomedir can't
take care of the missing homedir.
it's easy to reproduce:
apt-get install xdm
(nothing special, everything out of the box)
adduser dummy
...
rm -rf /home/dummy
cat /etc/pam.d/common-session
session optional pam_mkhomedir.so
session required pam_unix.so
and that's it. you try to login as dummy, the password is accepted,
a brief message of "login successful" or the like flashes on the screen,
and then the greeter part of xdm sigsegvs, and the main xdm shuts
itself and the x server down.
fallout in the xdm.log:
Thu May 14 15:28:29 2009 xdm info (pid 5504): sourcing /etc/X11/xdm/Xsetup
Thu May 14 15:29:06 2009 xdm info (pid 5504): sourcing /etc/X11/xdm/Xstartup
Thu May 14 15:29:06 2009 xdm error (pid 5495): display :0 (pid 2816) exited
with unexpected status 5504
strace -f -p 5504 (the greeter child of xdm) shows that
immediately after the xstartup process finishes, xdm does a stat on
the not-yet-existing homedir and sigsegv's straight away.
relevant bits from this trace are included here:
Process 5504 attached - interrupt to quit
...
open("/etc/X11/xdm/Xstartup", O_RDONLY) = 4
close(4) = 0
time(NULL) = 1242278946
stat64("/etc/localtime", {st_mode=S_IFREG|0644, st_size=413, ...}) = 0
stat64("/etc/localtime", {st_mode=S_IFREG|0644, st_size=413, ...}) = 0
write(2, "Thu May 14 15:29:06 2009 xdm info"..., 46) = 46
write(2, "sourcing /etc/X11/xdm/Xstartup\n"..., 31) = 31
clone(Process 5526 attached
child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD,
child_tidptr=0xb7bcd958) = 5526
[pid 5526] setsid() = 5526
...lots of xstartup activity...
[pid 5526] open("/var/log/lastlog", O_RDWR|O_LARGEFILE) = 3
[pid 5526] _llseek(3, 292584, [292584], SEEK_SET) = 0
[pid 5526] write(3,
"\"\254\vJ:0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 292) =
292
[pid 5526] close(3) = 0
[pid 5526] exit_group(0) = ?
Process 5504 resumed
Process 5526 detached
<... wait4 resumed> [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, NULL) = 5526
--- SIGCHLD (Child exited) @ 0 (0) ---
rt_sigprocmask(SIG_BLOCK, NULL, [], 8) = 0
rt_sigaction(SIGTERM, {0x8053570, [], 0}, {SIG_DFL}, 8) = 0
open("/etc/passwd", O_RDONLY|O_CLOEXEC) = 4
_llseek(4, 0, [0], SEEK_CUR) = 0
fstat64(4, {st_mode=S_IFREG|0644, st_size=1196, ...}) = 0
mmap2(NULL, 1196, PROT_READ, MAP_SHARED, 4, 0) = 0xb808a000
_llseek(4, 1196, [1196], SEEK_SET) = 0
munmap(0xb808a000, 1196) = 0
close(4) = 0
stat64("/home/dummy", 0xbfbacda8) = -1 ENOENT (No such file or directory)
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
Process 5504 detached
etch's xdm worked fine in the same environment, and so does lenny's kdm
so i'm *absolutely* certain that pam_mkhomedir is not the culprit here.
regards
az
-- System Information:
Debian Release: 5.0.1
APT prefers stable
APT policy: (990, 'stable'), (980, 'testing'), (970, 'unstable')
Architecture: i386 (i686)
--- End Message ---
--- Begin Message ---
On Thu, May 14, 2009 at 15:47:40 +1000, Alexander Zangerl wrote:
> xdm reproducibly crashes when the user's home directory does not exist,
> before actually doing any pam session handling - so that pam_mkhomedir can't
> take care of the missing homedir.
>
> it's easy to reproduce:
>
> apt-get install xdm
> (nothing special, everything out of the box)
> adduser dummy
> ...
> rm -rf /home/dummy
> cat /etc/pam.d/common-session
> session optional pam_mkhomedir.so
> session required pam_unix.so
>
> and that's it. you try to login as dummy, the password is accepted,
> a brief message of "login successful" or the like flashes on the screen,
> and then the greeter part of xdm sigsegvs, and the main xdm shuts
> itself and the x server down.
>
I can't reproduce this with xdm 1.1.10, so I assume it's been fixed
since then (I put the pam_mkhomedir.so line in /etc/pam.d/xdm after the
common-session stuff instead, but hopefully that's not a relevant
difference...).
Cheers,
Julien
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