From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id E87FAIpQGVssCAAAmS7hNA ; Thu, 07 Jun 2018 15:34:34 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id E61876074D; Thu, 7 Jun 2018 15:34:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id AD46660590; Thu, 7 Jun 2018 15:34:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org AD46660590 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935331AbeFGPea (ORCPT + 25 others); Thu, 7 Jun 2018 11:34:30 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:40651 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934316AbeFGOmw (ORCPT ); Thu, 7 Jun 2018 10:42:52 -0400 Received: from [148.252.241.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1fQvbX-0005Zo-D8; Thu, 07 Jun 2018 15:09:31 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1fQvb9-000383-O5; Thu, 07 Jun 2018 15:09:07 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Sven Eckelmann" , "Simon Wunderlich" , "Maximilian Wilhelm" , "Matthias Schiffer" Date: Thu, 07 Jun 2018 15:05:21 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 283/410] batman-adv: invalidate checksum on fragment reassembly In-Reply-To: X-SA-Exim-Connect-IP: 148.252.241.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.57-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Matthias Schiffer commit 3bf2a09da956b43ecfaa630a2ef9a477f991a46a upstream. A more sophisticated implementation could try to combine fragment checksums when all fragments have CHECKSUM_COMPLETE and are split at even offsets. For now, we just set ip_summed to CHECKSUM_NONE to avoid "hw csum failure" warnings in the kernel log when fragmented frames are received. In consequence, skb_pull_rcsum() can be replaced with skb_pull(). Note that in usual setups, packets don't reach batman-adv with CHECKSUM_COMPLETE (I assume NICs bail out of checksumming when they see batadv's ethtype?), which is why the log messages do not occur on every system using batman-adv. I could reproduce this issue by stacking batman-adv on top of a VXLAN interface. Fixes: 610bfc6bc99b ("batman-adv: Receive fragmented packets and merge") Tested-by: Maximilian Wilhelm Signed-off-by: Matthias Schiffer Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Ben Hutchings --- net/batman-adv/fragmentation.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -262,7 +262,8 @@ batadv_frag_merge_packets(struct hlist_h /* Move the existing MAC header to just before the payload. (Override * the fragment header.) */ - skb_pull_rcsum(skb_out, hdr_size); + skb_pull(skb_out, hdr_size); + skb_out->ip_summed = CHECKSUM_NONE; memmove(skb_out->data - ETH_HLEN, skb_mac_header(skb_out), ETH_HLEN); skb_set_mac_header(skb_out, -ETH_HLEN); skb_reset_network_header(skb_out);