Re: [PATCH net 0/9] rxrpc: Fix use of skb_cow_data()

[David Miller]

From: David Howells <dhowells@xxxxxxxxxx>
Date: Thu, 22 Aug 2019 13:22:33 +0100

> Here's a series of patches that fixes the use of skb_cow_data() in rxrpc.
> The problem is that skb_cow_data() indirectly requires that the maximum
> usage count on an sk_buff be 1, and it may generate an assertion failure in
> pskb_expand_head() if not.

It sounds like you are effectively doing a late unshare when you have to
do in-place encryption.

Why don't you just do an skb_unshare() at the beginning when you know that
you'll need to do that?