https://bugzilla.redhat.com/show_bug.cgi?id=488147#c21 explains that
this segfault comes not from unix_chkpwd, but from glibc which aborts
when a setuid or setgid application is started without fds (0,1,2) open
and opening a placeholder fd to either /dev/null or /dev/full fails with
a permissions problem.

And fds 1 and 2 are closed by pam_unix before launching unix_chkpwd,
which is what triggers the abort.

Ultimately the bug is in whatever has broken the standard devices on the
system, preventing the fds from being reopened.  But we may be able to
defend against this better by just not closing stdout/stderr in the
first place.

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/270781

Title:
  unix_chkpwd abnormal exit: 11 unix_chkpwd crashes under  gnome-
  screensaver and prevents unlock (/dev/null corruption?)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/pam/+bug/270781/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to