selinux: fix setting of security labels on NFS

commit 9fc2b4b436cff7d8403034676014f1be9d534942 upstream.

Before calling into the filesystem, vfs_setxattr calls
security_inode_setxattr, which ends up calling selinux_inode_setxattr in
our case.  That returns -EOPNOTSUPP whenever SBLABEL_MNT is not set.
SBLABEL_MNT was supposed to be set by sb_finish_set_opts, which sets it
only if selinux_is_sblabel_mnt returns true.

The selinux_is_sblabel_mnt logic was broken by eadcabc697e9 "SELinux: do
all flags twiddling in one place", which didn't take into the account
the SECURITY_FS_USE_NATIVE behavior that had been introduced for nfs
with eb9ae686507b "SELinux: Add new labeling type native labels".

This caused setxattr's of security labels over NFSv4.2 to fail.

Cc: Eric Paris <eparis@redhat.com>
Cc: David Quigley <dpquigl@davequigley.com>
Reported-by: Richard Chan <rc556677@outlook.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: added the stable dependency]
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 7dade28affba..212070e1de1a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -403,6 +403,7 @@ static int selinux_is_sblabel_mnt(struct super_block *sb)
         return sbsec->behavior == SECURITY_FS_USE_XATTR ||
                 sbsec->behavior == SECURITY_FS_USE_TRANS ||
                 sbsec->behavior == SECURITY_FS_USE_TASK ||
+                sbsec->behavior == SECURITY_FS_USE_NATIVE ||
                 /* Special handling. Genfs but also in-core setxattr handler */
                 !strcmp(sb->s_type->name, "sysfs") ||
                 !strcmp(sb->s_type->name, "pstore") ||