tls: rx: device: don't try to copy too much on detach

Tested: selftests
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2143700

commit d800a7b
Author: Jakub Kicinski <[email protected]>
Date:   Tue Aug 9 10:55:44 2022 -0700

    tls: rx: device: don't try to copy too much on detach

    Another device offload bug, we use the length of the output
    skb as an indication of how much data to copy. But that skb
    is sized to offset + record length, and we start from offset.
    So we end up double-counting the offset which leads to
    skb_copy_bits() returning -EFAULT.

    Reported-by: Tariq Toukan <[email protected]>
    Fixes: 84c61fe ("tls: rx: do not use the standard strparser")
    Tested-by: Ran Rozenstein <[email protected]>
    Link: https://lore.kernel.org/r/[email protected]
    Signed-off-by: Jakub Kicinski <[email protected]>

Signed-off-by: Sabrina Dubroca <[email protected]>

Author: Sabrina Dubroca

net/tls/tls_strp.c

@@ -41,7 +41,7 @@ static struct sk_buff *tls_strp_msg_make_copy(struct tls_strparser *strp)
 	struct sk_buff *skb;
 	int i, err, offset;
 
-	skb = alloc_skb_with_frags(0, strp->anchor->len, TLS_PAGE_ORDER,
+	skb = alloc_skb_with_frags(0, strp->stm.full_len, TLS_PAGE_ORDER,
 				   &err, strp->sk->sk_allocation);
 	if (!skb)
 		return NULL;