Boolean utilities segv's

[George C. Wilson]

Hi,

We found what appears to be a bug in libselinux.  The getsebool, setsebool,
and togglesebool all SIGSEGV when SELINUX=disabled.

The global that stores the selinuxfs mountpoint in libselinux, selinux_mnt, is
initialized to NULL.  selinuxfs is not mounted when SELinux is disabled,
therefore no mountpoint exists when init_selinuxmnt() scans /proc/mounts, and
selinux_mnt remains NULL.  So when get_bool_value() in booleans.c  attempts to
strlen(selinux_mnt), a SIGSEGV results.  The fix is to validate selinux_mnt
before the offending strlen() in get_bool_value(), line 101 of booleans.c from
selinux-usr-2004081908.  It probably would not hurt to validate name as well.
The same bug exists in FC3.

Thanks
-- 
George Wilson <ltcgcw at us.ibm.com>
IBM Linux Technology Center