From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pravin Shelar Subject: Re: [PATCH net] skbuff: Fix skb checksum flag on skb pull Date: Mon, 31 Aug 2015 20:29:02 -0700 Message-ID: References: <1441061746-1492-1-git-send-email-pshelar@nicira.com> <20150901014022.GA11983@Alexeis-MacBook-Pro-2.local> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: netdev To: Alexei Starovoitov Return-path: Received: from mail-ig0-f180.google.com ([209.85.213.180]:36454 "EHLO mail-ig0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751828AbbIAD3D (ORCPT ); Mon, 31 Aug 2015 23:29:03 -0400 Received: by igboj15 with SMTP id oj15so45499103igb.1 for ; Mon, 31 Aug 2015 20:29:02 -0700 (PDT) In-Reply-To: <20150901014022.GA11983@Alexeis-MacBook-Pro-2.local> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Aug 31, 2015 at 6:40 PM, Alexei Starovoitov wrote: > On Mon, Aug 31, 2015 at 03:55:46PM -0700, Pravin B Shelar wrote: >> VXLAN device can receive skb with checksum partial. But the checksum >> offset could be in outer header which is pulled on receive. Such skb >> can cause the panic when checksum is calculated on skb. Following patch >> fixes the bug by setting checksum unnecessary while pulling outer header. >> >> ---8<--- >> [ 13.800141] RIP: 0010:[] [] skb_checksum_help+0x144/0x150 >> [ 13.800141] RSP: 0000:ffff88011fd83940 EFLAGS: 00010292 >> [ 13.800141] RAX: 0000000000000042 RBX: ffff880114dd56c0 RCX: ffff8801188d9580 >> ... >> ... >> [ 13.852308] Call Trace: >> [ 13.852308] >> [ 13.852308] [] queue_userspace_packet+0x408/0x470 [openvswitch] >> [ 13.852308] [] ovs_dp_upcall+0x5d/0x60 [openvswitch] >> [ 13.852308] [] ovs_dp_process_packet_with_key+0xe6/0x100 [openvswitch] >> [ 13.852308] [] ovs_dp_process_received_packet+0x4b/0x80 [openvswitch] > > that doesn't look like upstream kernel. > The above two functions don't exist in net-next. > Bug was reported on older kernel. But the issue exist on net-next kernel. For example when vxlan checksum is turned on.