Scientific Linux Security Update : autofs on SL5.x i386/x86_64
Medium Nessus Plugin ID 63591
SynopsisThe remote Scientific Linux host is missing one or more security updates.
DescriptionA 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).
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 functionality.
SolutionUpdate the affected autofs and / or autofs-debuginfo packages.