From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: [net-next PATCH v2 7/8] udp: Do not copy destructor if one is not present Date: Fri, 04 May 2018 11:31:45 -0700 Message-ID: <20180504183110.5194.5449.stgit@localhost.localdomain> References: <20180504182537.5194.72775.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-it0-f68.google.com ([209.85.214.68]:36637 "EHLO mail-it0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751563AbeEDSbs (ORCPT ); Fri, 4 May 2018 14:31:48 -0400 Received: by mail-it0-f68.google.com with SMTP id e20-v6so4558370itc.1 for ; Fri, 04 May 2018 11:31:48 -0700 (PDT) In-Reply-To: <20180504182537.5194.72775.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 --- v2: Do not overwrite destructor if not sock_wfree as per Eric Drop WARN_ON as per Eric net/ipv4/udp_offload.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index fd94bbb369b2..e802f6331589 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); - gso_skb->destructor = NULL; + 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))) { - 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; }