Synopsis: Low: autofs security, bug fix, and enhancement update
Issue Date: 2013-01-08
CVE Numbers: CVE-2012-2697
A bug fix included in SLBA-2012:0264 introduced a denial of service flaw in
autofs. When using autofs with LDAP, a local user could use this flaw to crash
autofs, preventing future mount requests from being processed until the autofs
service was restarted. Note: This flaw did not impact existing mounts (except
for preventing mount expiration). (CVE-2012-2697)
This update also fixes the following bugs:
* The autofs init script sometimes timed out waiting for the automount daemon
to exit and returned a shutdown failure if the daemon failed to exit in time.
To resolve this problem, the amount of time that the init script waits for the
daemon has been increased to allow for cases where servers are slow to respond
or there are many active mounts.
* Due to an omission when backporting a change, autofs attempted to download
the entire LDAP map at startup. This mistake has now been corrected.
* A function to check the validity of a mount location was meant to check only
for a small subset of map location errors. A recent modification in error
reporting inverted a logic test in this validating function. Consequently, the
scope of the test was widened, which caused the automount daemon to report
false positive failures. With this update, the faulty logic test has been
corrected and false positive failures no longer occur.
* When there were many attempts to access invalid or non-existent keys, the
automount daemon used excessive CPU resources. As a consequence, systems
sometimes became unresponsive. The code has been improved so that automount
checks for invalid keys earlier in the process which has eliminated a
significant amount of the processing overhead.
* The auto.master(5) man page did not document the “-t, –timeout” option in
the FORMAT options section. This update adds this information to the man page.
This update also adds the following enhancement:
* Previously, it was not possible to configure separate timeout values for
individual direct map entries in the autofs master map. This update adds this
– Scientific Linux Development Team