Merge branch 'ucount-rlimit-fixes-for-v5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull ucount rlimit fix from Eric Biederman.

Make sure the ucounts have a reference to the user namespace it refers
to, so that users that themselves don't carry such a reference around
can safely use the ucount functions.

* 'ucount-rlimit-fixes-for-v5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ucount:  Make get_ucount a safe get_user replacement

Author: torvalds

kernel/ucount.c

@@ -190,6 +190,7 @@ struct ucounts *alloc_ucounts(struct user_namespace *ns, kuid_t uid)
 			kfree(new);
 		} else {
 			hlist_add_head(&new->node, hashent);
+			get_user_ns(new->ns);
 			spin_unlock_irq(&ucounts_lock);
 			return new;
 		}
@@ -210,6 +211,7 @@ void put_ucounts(struct ucounts *ucounts)
 	if (atomic_dec_and_lock_irqsave(&ucounts->count, &ucounts_lock, flags)) {
 		hlist_del_init(&ucounts->node);
 		spin_unlock_irqrestore(&ucounts_lock, flags);
+		put_user_ns(ucounts->ns);
 		kfree(ucounts);
 	}
 }