From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: [net-next PATCH 4/5] udp: Do not copy destructor if one is not present Date: Thu, 03 May 2018 17:33:39 -0700 Message-ID: <20180504003339.4496.26712.stgit@localhost.localdomain> References: <20180504002817.4496.64616.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org, willemb@google.com, davem@davemloft.net Return-path: Received: from mail-pg0-f67.google.com ([74.125.83.67]:33684 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751116AbeEDAdm (ORCPT ); Thu, 3 May 2018 20:33:42 -0400 Received: by mail-pg0-f67.google.com with SMTP id i194-v6so14286480pgd.0 for ; Thu, 03 May 2018 17:33:41 -0700 (PDT) In-Reply-To: <20180504002817.4496.64616.stgit@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: From: Alexander Duyck 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. Signed-off-by: Alexander Duyck --- net/ipv4/udp_offload.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index fd94bbb369b2..52760660d674 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -195,6 +195,7 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, unsigned int sum_truesize = 0; struct udphdr *uh; unsigned int mss; + bool copy_dtor; __sum16 check; __be16 newlen; @@ -208,12 +209,14 @@ 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; + WARN_ON_ONCE(gso_skb->destructor && !copy_dtor); gso_skb->destructor = NULL; segs = skb_segment(gso_skb, features); if (unlikely(IS_ERR_OR_NULL(segs))) { - gso_skb->destructor = sock_wfree; + if (copy_dtor) + gso_skb->destructor = sock_wfree; return segs; } @@ -234,9 +237,11 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, (__force u32)newlen)); for (;;) { - seg->destructor = sock_wfree; - seg->sk = sk; - sum_truesize += seg->truesize; + if (copy_dtor) { + seg->destructor = sock_wfree; + seg->sk = sk; + sum_truesize += seg->truesize; + } if (!seg->next) break; @@ -268,7 +273,9 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb, uh->check = gso_make_checksum(seg, ~check); /* 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); out: return segs; }