Note: This is an archival copy of Security Sun Alert 201527 as previously published on
Latest version of this security advisory is available from as Sun Alert 1001139.1.
Article ID : 1001139.1
Article Type : Sun Alerts (SURE)
Last reviewed : 2003-03-04
Audience : PUBLIC
Copyright Notice: Copyright © 2010, Oracle Corporation and/or its affiliates.

UFS File Systems With Logging Enabled are Vulnerable to a Denial of Service (DoS) Attack


Release Phase

Solaris 9 Operating System

Bug Id

Date of Resolved Release


A local unprivileged user may be able to cause a denial of service attack so that a ufs file system will appear to be non-functional (non-responding) system wide until the system is rebooted.

Contributing Factors

This issue can occur in the following releases:

SPARC Platform

  • Solaris 9 without patch 113454-03

Note: Solaris 2.6, Solaris 7 and Solaris 8 are not affected by this issue.

Note: Solaris 9 on x86 platforms is not affected by this issue.

This issue may only occur on ufs file systems that are mounted with the "logging" option enabled. To see if any ufs file systems have logging enabled, see the "/etc/vfstab" file. For example, the following "/etc/vfstab" file:

  #device         device          mount           FS      fsck    mount   mount
#to mount       to fsck         point           type    pass    at boot options
/dev/dsk/c0t2d0s0 /dev/rdsk/c0t2d0s0 /          ufs     2       no      logging

would indicate an enabled "logging" option for the "/dev/dsk/c0t2d0s0" ufs file system.

Solaris 2.5.1 will not be evaluated regarding the potential impact of the issue described in this Sun Alert document.


The ufs file system becomes unresponsive to any request system wide (it appears hung).


To work around the described issue, disable logging for ufs file systems

  1. by removing the "logging" option in the "/etc/vfstab" and rebooting, or
  2. by issuing the following command as a root user for any ufs file system:
        # mount -o remount,nologging <mount_point>
    (here, "<mount_point>" has to be replaced by the desired file systems mount point). No reboot is required (this setting will only last until the next reboot).

Please remember to re-enable logging once the appropriate patch has been installed on the system.


This issue is addressed in the following releases:

SPARC Platform

  • Solaris 9 with patch 113454-03 or later

Modification History
Date: 11-MAR-2003
  • modified patch revision from 113454-04 to 113454-03



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