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Commit 4fb57e94 authored by Alexander Duyck's avatar Alexander Duyck Committed by Sean Tranchetti
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udp: Do not copy destructor if one is not present 



This patch makes it so that if a destructor is not present we avoid trying
to update the skb socket or any reference counting that would be associated
with the NULL socket and/or descriptor. By doing this we can support
traffic coming from another namespace without any issues.

Change-Id: I61155db99242c0c39f0a19f7a455c0a90d1ac8f3
CRs-Fixed: 2351793
Acked-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Git-commit: 04d55b25
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git


Signed-off-by: default avatarSean Tranchetti <stranche@codeaurora.org>
parent e0914a57

net/ipv4/udp_offload.c

+14 −8
Original line number Diff line number Diff line
@@ -195,6 +195,7 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, 
	struct sk_buff *segs, *seg;

	struct udphdr *uh;

	unsigned int mss;

	bool copy_dtor;

	__sum16 check;

	__be16 newlen;
@@ -205,11 +206,13 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, 
	skb_pull(gso_skb, sizeof(*uh));



	/* clear destructor to avoid skb_segment assigning it to tail */

	WARN_ON_ONCE(gso_skb->destructor != sock_wfree);

	copy_dtor = gso_skb->destructor == sock_wfree;

	if (copy_dtor)

		gso_skb->destructor = NULL;



	segs = skb_segment(gso_skb, features);

	if (unlikely(IS_ERR_OR_NULL(segs))) {

		if (copy_dtor)

			gso_skb->destructor = sock_wfree;

		return segs;

	}
@@ -229,9 +232,11 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, 
	check = csum16_add(csum16_sub(uh->check, uh->len), newlen);



	for (;;) {

		if (copy_dtor) {

			seg->destructor = sock_wfree;

			seg->sk = sk;

			sum_truesize += seg->truesize;

		}



		if (!seg->next)

			break;
@@ -263,8 +268,9 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, 
		uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0;



	/* update refcount for the packet */

	refcount_add(sum_truesize - gso_skb->truesize, &sk->sk_wmem_alloc);



	if (copy_dtor)

		refcount_add(sum_truesize - gso_skb->truesize,

			     &sk->sk_wmem_alloc);

	return segs;

}

EXPORT_SYMBOL_GPL(__udp_gso_segment);