Commit 5a552617 authored Apr 09, 2008 by Eric Paris Committed by James Morris Apr 10, 2008

SELinux: don't BUG if fs reuses a superblock

I (wrongly) assumed that nfs_xdev_get_sb() would not ever share a superblock
and so cloning mount options would always be correct. Turns out that isn't
the case and we could fall over a BUG_ON() that wasn't a BUG at all. Since
there is little we can do to reconcile different mount options this patch
just leaves the sb alone and the first set of options wins.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: James Morris <jmorris@namei.org>

parent 7180c4c9

security/selinux/hooks.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -760,13 +760,13 @@ static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
		* this early in the boot process. */
		BUG_ON(!ss_initialized);

		/* this might go away sometime down the line if there is a new user
		* of clone, but for now, nfs better not get here... */
		BUG_ON(newsbsec->initialized);

		/* how can we clone if the old one wasn't set up?? */
		BUG_ON(!oldsbsec->initialized);

		/* if fs is reusing a sb, just let its options stand... */
		if (newsbsec->initialized)
		return;

		mutex_lock(&newsbsec->lock);

		newsbsec->flags = oldsbsec->flags;

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