From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Klassert Subject: [PATCH 1/5] esp4: Fix udpencap for local TCP packets. Date: Tue, 23 May 2017 07:33:40 +0200 Message-ID: <1495517624-27096-2-git-send-email-steffen.klassert@secunet.com> References: <1495517624-27096-1-git-send-email-steffen.klassert@secunet.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Herbert Xu , Steffen Klassert , To: David Miller Return-path: Received: from a.mx.secunet.com ([62.96.220.36]:45118 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933151AbdEWFdx (ORCPT ); Tue, 23 May 2017 01:33:53 -0400 In-Reply-To: <1495517624-27096-1-git-send-email-steffen.klassert@secunet.com> Sender: netdev-owner@vger.kernel.org List-ID: Locally generated TCP packets are usually cloned, so we do skb_cow_data() on this packets. After that we need to reload the pointer to the esp header. On udpencap this header has an offset to skb_transport_header, so take this offset into account. Fixes: 67d349ed603 ("net/esp4: Fix invalid esph pointer crash") Fixes: fca11ebde3f0 ("esp4: Reorganize esp_output") Reported-by: Don Bowman Signed-off-by: Steffen Klassert --- net/ipv4/esp4.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 65cc02b..93322f8 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -248,6 +248,7 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info * u8 *tail; u8 *vaddr; int nfrags; + int esph_offset; struct page *page; struct sk_buff *trailer; int tailen = esp->tailen; @@ -313,11 +314,13 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info * } cow: + esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb); + nfrags = skb_cow_data(skb, tailen, &trailer); if (nfrags < 0) goto out; tail = skb_tail_pointer(trailer); - esp->esph = ip_esp_hdr(skb); + esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset); skip_cow: esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); -- 2.7.4