linux-stable/security
Scott Mayhew 0b4d3452b8 security/selinux: allow security_sb_clone_mnt_opts to enable/disable native labeling behavior
When an NFSv4 client performs a mount operation, it first mounts the
NFSv4 root and then does path walk to the exported path and performs a
submount on that, cloning the security mount options from the root's
superblock to the submount's superblock in the process.

Unless the NFS server has an explicit fsid=0 export with the
"security_label" option, the NFSv4 root superblock will not have
SBLABEL_MNT set, and neither will the submount superblock after cloning
the security mount options.  As a result, setxattr's of security labels
over NFSv4.2 will fail.  In a similar fashion, NFSv4.2 mounts mounted
with the context= mount option will not show the correct labels because
the nfs_server->caps flags of the cloned superblock will still have
NFS_CAP_SECURITY_LABEL set.

Allowing the NFSv4 client to enable or disable SECURITY_LSM_NATIVE_LABELS
behavior will ensure that the SBLABEL_MNT flag has the correct value
when the client traverses from an exported path without the
"security_label" option to one with the "security_label" option and
vice versa.  Similarly, checking to see if SECURITY_LSM_NATIVE_LABELS is
set upon return from security_sb_clone_mnt_opts() and clearing
NFS_CAP_SECURITY_LABEL if necessary will allow the correct labels to
be displayed for NFSv4.2 mounts mounted with the context= mount option.

Resolves: https://github.com/SELinuxProject/selinux-kernel/issues/35

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Tested-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-06-09 16:17:47 -04:00
..
apparmor apparmorfs: replace CURRENT_TIME with current_time() 2017-05-08 17:15:15 -07:00
integrity Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into next 2017-04-19 22:00:15 +10:00
keys treewide: use kv[mz]alloc* rather than opencoded variants 2017-05-08 17:15:13 -07:00
loadpin security: mark LSM hooks as __ro_after_init 2017-03-06 11:00:15 +11:00
selinux security/selinux: allow security_sb_clone_mnt_opts to enable/disable native labeling behavior 2017-06-09 16:17:47 -04:00
smack Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-05-09 09:12:53 -07:00
tomoyo Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-05-03 08:50:52 -07:00
yama security: mark LSM hooks as __ro_after_init 2017-03-06 11:00:15 +11:00
commoncap.c security: mark LSM hooks as __ro_after_init 2017-03-06 11:00:15 +11:00
device_cgroup.c security/device_cgroup: Fix RCU_LOCKDEP_WARN() condition 2015-09-03 18:13:10 -07:00
inode.c fs: constify tree_descr arrays passed to simple_fill_super() 2017-04-26 23:54:06 -04:00
Kconfig IB/core: Enforce PKey security on QPs 2017-05-23 12:26:59 -04:00
lsm_audit.c selinux: Add IB Port SMP access vector 2017-05-23 12:28:02 -04:00
Makefile LSM: LoadPin for kernel file loading restrictions 2016-04-21 10:47:27 +10:00
min_addr.c
security.c security/selinux: allow security_sb_clone_mnt_opts to enable/disable native labeling behavior 2017-06-09 16:17:47 -04:00