Commit 4ef9e11d authored Dec 29, 2010 by Hillf Danton Committed by Linus Torvalds Dec 29, 2010

fix freeing user_struct in user cache



When racing on adding into user cache, the new allocated from mm slab
is freed without putting user namespace.

Since the user namespace is already operated by getting, putting has
to be issued.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 387c31c7

kernel/user.c

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -158,6 +158,7 @@ struct user_struct alloc_uid(struct user_namespace ns, uid_t uid)
	spin_lock_irq(&uidhash_lock);		spin_lock_irq(&uidhash_lock);
	up = uid_hash_find(uid, hashent);		up = uid_hash_find(uid, hashent);
	if (up) {		if (up) {
			put_user_ns(ns);
	key_put(new->uid_keyring);		key_put(new->uid_keyring);
	key_put(new->session_keyring);		key_put(new->session_keyring);
	kmem_cache_free(uid_cachep, new);		kmem_cache_free(uid_cachep, new);