linux/security/selinux
Eric Paris 415103f993 SELinux: do not compute transition labels on mountpoint labeled filesystems
selinux_inode_init_security computes transitions sids even for filesystems
that use mount point labeling.  It shouldn't do that.  It should just use
the mount point label always and no matter what.

This causes 2 problems.  1) it makes file creation slower than it needs to be
since we calculate the transition sid and 2) it allows files to be created
with a different label than the mount point!

# id -Z
staff_u:sysadm_r:sysadm_t:s0-s0:c0.c1023
# sesearch --type --class file --source sysadm_t --target tmp_t
Found 1 semantic te rules:
   type_transition sysadm_t tmp_t : file user_tmp_t;

# mount -o loop,context="system_u:object_r:tmp_t:s0"  /tmp/fs /mnt/tmp

# ls -lZ /mnt/tmp
drwx------. root root system_u:object_r:tmp_t:s0       lost+found
# touch /mnt/tmp/file1
# ls -lZ /mnt/tmp
-rw-r--r--. root root staff_u:object_r:user_tmp_t:s0   file1
drwx------. root root system_u:object_r:tmp_t:s0       lost+found

Whoops, we have a mount point labeled filesystem tmp_t with a user_tmp_t
labeled file!

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Reviewed-by: James Morris <jmorris@namei.org>
2010-12-02 16:14:51 -05:00
..
include SELinux: allow userspace to read policy back out of the kernel 2010-10-21 10:12:58 +11:00
ss SELinux: merge policydb_index_classes and policydb_index_others 2010-11-30 17:28:58 -05:00
.gitignore SELinux: add .gitignore files for dynamic classes 2009-10-24 09:42:27 +08:00
avc.c SELinux: special dontaudit for access checks 2010-08-02 15:35:07 +10:00
exports.c secmark: make secmark object handling generic 2010-10-21 10:12:48 +11:00
hooks.c SELinux: do not compute transition labels on mountpoint labeled filesystems 2010-12-02 16:14:51 -05:00
Kconfig selinux: Deprecate and schedule the removal of the the compat_net functionality 2008-12-31 12:54:11 -05:00
Makefile selinux: change to new flag variable 2010-10-21 10:12:40 +11:00
netif.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
netlabel.c Merge branch 'master' into next 2010-05-06 10:56:07 +10:00
netlink.c Merge branch 'master' into next 2010-05-06 10:56:07 +10:00
netnode.c selinux: remove all rcu head initializations 2010-08-02 15:33:35 +10:00
netport.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
nlmsgtab.c Selinux: Remove unused headers skbuff.h in selinux/nlmsgtab.c 2010-03-04 08:51:06 +11:00
selinuxfs.c SELinux: do not set automatic i_ino in selinuxfs 2010-11-30 17:28:57 -05:00
xfrm.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00