Re: [PATCH] KEYS: The request_key() syscall should link an existing key to the dest keyring

From: David Howells
Date: Wed Apr 28 2010 - 10:59:09 EST


Vegard Nossum <vegard.nossum@xxxxxxxxx> wrote:

> 1. Is it correct to return -EINPROGRESS in this case?

Yes - it prevents construct_key_and_link() from going on to call
construct_key(). The key in question is returned in *_key.

However, I don't think I handle other errors coming back from
construct_alloc_key() correctly.

> 2. (Why) Shouldn't the return value of __key_link() be checked?

It should. In fact, I should probably precheck and preallocate the keyring to
make sure I don't get errors after allocating the new key.

> 3. In __key_link(), shouldn't rcu_dereference() be used when accessing
> keyring->payload.subscriptions?

No. We have to hold a write lock on the keyring semaphore if we're going to
call __key_link() to add something to it.

We should, however, call rcu_dereference_protected().

You should find a patch for this in your inbox.

David
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