From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: [net-next PATCH v3 6/6] udp: Do not copy destructor if one is not present Date: Mon, 07 May 2018 11:08:52 -0700 Message-ID: <20180507180852.3486.27748.stgit@localhost.localdomain> References: <20180507180310.3486.35994.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-pl0-f65.google.com ([209.85.160.65]:36211 "EHLO mail-pl0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752659AbeEGSIy (ORCPT ); Mon, 7 May 2018 14:08:54 -0400 Received: by mail-pl0-f65.google.com with SMTP id v24-v6so205945plo.3 for ; Mon, 07 May 2018 11:08:53 -0700 (PDT) In-Reply-To: <20180507180310.3486.35994.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. Acked-by: Willem de Bruijn Signed-off-by: Alexander Duyck --- net/ipv4/udp_offload.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index d4f2daca0c33..ede2a7305b90 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, struct sk_buff *segs, *seg; struct udphdr *uh; unsigned int mss; + bool copy_dtor; __sum16 check; __be16 newlen; @@ -205,12 +206,14 @@ 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; } @@ -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 (;;) { - 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; @@ -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);