Commit aad34f76 authored Aug 13, 2014 by Eric W. Biederman Committed by Greg Kroah-Hartman Jan 08, 2015

mnt: Implicitly add MNT_NODEV on remount when it was implicitly added by mount



commit 3e186641 upstream.

Now that remount is properly enforcing the rule that you can't remove
nodev at least sandstorm.io is breaking when performing a remount.

It turns out that there is an easy intuitive solution implicitly
add nodev on remount when nodev was implicitly added on mount.

Tested-by: Cedric Bosdonnat <cbosdonnat@suse.com>
Tested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 46b4fd75

fs/namespace.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -1966,8 +1966,14 @@ static int do_remount(struct path *path, int flags, int mnt_flags,
		}
		if ((mnt->mnt.mnt_flags & MNT_LOCK_NODEV) &&
		!(mnt_flags & MNT_NODEV)) {
		/* Was the nodev implicitly added in mount? */
		if ((mnt->mnt_ns->user_ns != &init_user_ns) &&
		!(sb->s_type->fs_flags & FS_USERNS_DEV_MOUNT)) {
		mnt_flags \|= MNT_NODEV;
		} else {
		return -EPERM;
		}
		}
		if ((mnt->mnt.mnt_flags & MNT_LOCK_NOSUID) &&
		!(mnt_flags & MNT_NOSUID)) {
		return -EPERM;