[PATCH] selinux: fix setting of security labels on NFS

[bfields@fieldses.org (J. Bruce Fields)]

From: "J. Bruce Fields" <bfields@redhat.com>

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: stable@kernel.org
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>
---
 security/selinux/hooks.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index e8a060bd9677..171fb30e4b99 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") ||
-- 
1.9.3