[PATCH] key: plug request_key_auth memleak

Plug request_key_auth memleak. This can be triggered by unprivileged
users, so is local DoS.

Signed-off-by: Chris Wright <[e-mail]>
Signed-Off-By: David Howells <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

security/keys/request_key_auth.c

···
 	kenter("{%d}", key->serial);
 
 	key_put(rka->target_key);
+	kfree(rka);
 
 } /* end request_key_auth_destroy() */