android_kernel_samsung_msm8976/security
Paul Moore 913a13b6da selinux: correctly label /proc inodes in use before the policy is loaded
commit f64410ec665479d7b4b77b7519e814253ed0f686 upstream.

This patch is based on an earlier patch by Eric Paris, he describes
the problem below:

  "If an inode is accessed before policy load it will get placed on a
   list of inodes to be initialized after policy load.  After policy
   load we call inode_doinit() which calls inode_doinit_with_dentry()
   on all inodes accessed before policy load.  In the case of inodes
   in procfs that means we'll end up at the bottom where it does:

     /* Default to the fs superblock SID. */
     isec->sid = sbsec->sid;

     if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
             if (opt_dentry) {
                     isec->sclass = inode_mode_to_security_class(...)
                     rc = selinux_proc_get_sid(opt_dentry,
                                               isec->sclass,
                                               &sid);
                     if (rc)
                             goto out_unlock;
                     isec->sid = sid;
             }
     }

   Since opt_dentry is null, we'll never call selinux_proc_get_sid()
   and will leave the inode labeled with the label on the superblock.
   I believe a fix would be to mimic the behavior of xattrs.  Look
   for an alias of the inode.  If it can't be found, just leave the
   inode uninitialized (and pick it up later) if it can be found, we
   should be able to call selinux_proc_get_sid() ..."

On a system exhibiting this problem, you will notice a lot of files in
/proc with the generic "proc_t" type (at least the ones that were
accessed early in the boot), for example:

   # ls -Z /proc/sys/kernel/shmmax | awk '{ print $4 " " $5 }'
   system_u:object_r:proc_t:s0 /proc/sys/kernel/shmmax

However, with this patch in place we see the expected result:

   # ls -Z /proc/sys/kernel/shmmax | awk '{ print $4 " " $5 }'
   system_u:object_r:sysctl_kernel_t:s0 /proc/sys/kernel/shmmax

Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-14 06:42:14 -07:00
..
apparmor new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
integrity Revert "ima: policy for RAMFS" 2013-11-29 11:11:44 -08:00
keys aio: don't include aio.h in sched.h 2013-05-07 20:16:25 -07:00
selinux selinux: correctly label /proc inodes in use before the policy is loaded 2014-04-14 06:42:14 -07:00
smack Smack: include magic.h in smackfs.c 2013-04-03 13:13:51 +11:00
tomoyo Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
yama yama: Better permission check for ptraceme 2013-03-26 13:17:58 -07:00
capability.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2013-04-30 16:27:51 -07:00
commoncap.c kill f_vfsmnt 2013-02-26 02:46:10 -05:00
device_cgroup.c devcg: remove parent_cgroup. 2013-04-18 11:34:35 -07:00
inode.c
Kconfig
lsm_audit.c
Makefile
min_addr.c
security.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2013-04-30 16:27:51 -07:00