SELinux: Enable setting security contexts on rootfs inodes.

rootfs (ramfs) can support setting of security contexts
by userspace due to the vfs fallback behavior of calling
the security module to set the in-core inode state
for security.* attributes when the filesystem does not
provide an xattr handler.  No xattr handler required
as the inodes are pinned in memory and have no backing
store.

This is useful in allowing early userspace to label individual
files within a rootfs while still providing a policy-defined
default via genfs.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4bc068b3773dbd64e0e9b0b983ceb168a36846a3..911b780fcf802c44368eb12a77bd5cf011db100c 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -406,6 +406,13 @@ static int sb_finish_set_opts(struct super_block *sb)
        if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
                sbsec->flags |= SE_SBLABELSUPP;
 
+       /*
+        * Special handling for rootfs. Is genfs but supports
+        * setting SELinux context on in-core inodes.
+        */
+       if (strncmp(sb->s_type->name, "rootfs", sizeof("rootfs")) == 0)
+               sbsec->flags |= SE_SBLABELSUPP;
+
        /* Initialize the root inode. */
        rc = inode_doinit_with_dentry(root_inode, root);