--- fs/namespace.c

+++ fs/namespace.c

@@ -1119,8 +1119,15 @@ SYSCALL_DEFINE2(umount, char __user *, n

{

struct path path;

int retval;

+ int lookup_flags = 0;

- retval = user_path(name, &path);

+ if (flags & ~(MNT_FORCE | MNT_DETACH | MNT_EXPIRE | UMOUNT_NOFOLLOW))

+ return -EINVAL;

+

+ if (!(flags & UMOUNT_NOFOLLOW))

+ lookup_flags |= LOOKUP_FOLLOW;

+

+ retval = user_path_at(AT_FDCWD, name, lookup_flags, &path);

if (retval)

goto out;

retval = -EINVAL;