Description of problem: When establishing an inbound IPSec/L2TP VPN tunnel with Strongswan/ppp/xl2tpd, each incoming packet causes the message "ppp0: hw csum failure" in /var/log/messages: Mar 10 16:35:31 gw kernel: [133272.735620] ppp0: hw csum failure Mar 10 16:35:31 gw kernel: [133272.735719] CPU: 1 PID: 26594 Comm: firewall-cmd Not tainted 3.18.7-200.fc21.x86_64 #1 Mar 10 16:35:31 gw kernel: [133272.735720] Hardware name: ASUS All Series/Z87-K, BIOS 1401 07/29/2014 Mar 10 16:35:31 gw kernel: [133272.735721] 0000000000000000 0000000017b5c96d ffff88011fb03a98 ffffffff8175e686 Mar 10 16:35:31 gw kernel: [133272.735723] 0000000000000000 ffff8800bebcd000 ffff88011fb03ab8 ffffffff81647122 Mar 10 16:35:31 gw kernel: [133272.735725] ffffffff816358f0 ffff8800b6b64500 ffff88011fb03af8 ffffffff8163e305 Mar 10 16:35:31 gw kernel: [133272.735726] Call Trace: Mar 10 16:35:31 gw kernel: [133272.735727] <IRQ> [<ffffffff8175e686>] dump_stack+0x46/0x58 Mar 10 16:35:31 gw kernel: [133272.735735] [<ffffffff81647122>] netdev_rx_csum_fault+0x42/0x50 Mar 10 16:35:31 gw kernel: [133272.735737] [<ffffffff816358f0>] ? reqsk_fastopen_remove+0x150/0x150 Mar 10 16:35:31 gw kernel: [133272.735740] [<ffffffff8163e305>] __skb_checksum_complete+0xc5/0xd0 Mar 10 16:35:31 gw kernel: [133272.735743] [<ffffffff816dea6a>] nf_ip_checksum+0xea/0x120 Mar 10 16:35:31 gw kernel: [133272.735751] [<ffffffffa0474973>] tcp_error+0xe3/0x230 [nf_conntrack] Mar 10 16:35:31 gw kernel: [133272.735755] [<ffffffffa046f94b>] nf_conntrack_in+0xeb/0xa60 [nf_conntrack] Mar 10 16:35:31 gw kernel: [133272.735757] [<ffffffff81649bd2>] ? __netif_receive_skb_core+0x582/0x820 Mar 10 16:35:31 gw kernel: [133272.735761] [<ffffffff81689760>] ? inet_del_offload+0x40/0x40 Mar 10 16:35:31 gw kernel: [133272.735770] [<ffffffffa049a3a2>] ipv4_conntrack_in+0x22/0x30 [nf_conntrack_ipv4] Mar 10 16:35:31 gw kernel: [133272.735772] [<ffffffff816802ea>] nf_iterate+0xaa/0xc0 Mar 10 16:35:31 gw kernel: [133272.735775] [<ffffffff81689760>] ? inet_del_offload+0x40/0x40 Mar 10 16:35:31 gw kernel: [133272.735776] [<ffffffff81680384>] nf_hook_slow+0x84/0x130 Mar 10 16:35:31 gw kernel: [133272.735778] [<ffffffff81689760>] ? inet_del_offload+0x40/0x40 Mar 10 16:35:31 gw kernel: [133272.735779] [<ffffffff8168a1ce>] ip_rcv+0x2fe/0x3a0 Mar 10 16:35:31 gw kernel: [133272.735781] [<ffffffff81649bd2>] __netif_receive_skb_core+0x582/0x820 Mar 10 16:35:31 gw kernel: [133272.735784] [<ffffffff81649e8a>] __netif_receive_skb+0x1a/0x80 Mar 10 16:35:31 gw kernel: [133272.735785] [<ffffffff8164ab72>] process_backlog+0xa2/0x150 Mar 10 16:35:31 gw kernel: [133272.735787] [<ffffffff8164a33a>] net_rx_action+0x13a/0x240 Mar 10 16:35:31 gw kernel: [133272.735790] [<ffffffff8109d7a4>] __do_softirq+0x124/0x2d0 Mar 10 16:35:31 gw kernel: [133272.735792] [<ffffffff8109db75>] irq_exit+0x125/0x130 Mar 10 16:35:31 gw kernel: [133272.735795] [<ffffffff817680fa>] do_IRQ+0x5a/0xf0 Mar 10 16:35:31 gw kernel: [133272.735797] [<ffffffff81765f2d>] common_interrupt+0x6d/0x6d Mar 10 16:35:31 gw kernel: [133272.735798] <EOI> Version-Release number of selected component (if applicable): [root@gw ~]# uname -r 3.18.7-200.fc21.x86_64 [root@gw ~]# rpm -qva strongswan xl2tpd ppp xl2tpd-1.3.6-6.fc21.x86_64 strongswan-5.2.0-4.fc21.x86_64 ppp-2.4.7-6.fc21.x86_64 How reproducible: Always Steps to Reproduce: 1. Configure Strongswan/xl2tpd/ppp as an IPSec/L2TP VPN server 2. Establish a VPN connection from a remote host 3. Generate packets over the VPN tunnel Actual results: Log flooded with kernel messages Expected results: No log flooding Additional info: N/A
Possible duplicate bug which was opened against FC20: https://bugzilla.redhat.com/show_bug.cgi?id=1148612
Same issue on my PC with IPSec/L2TP VPN connection /var/log/messages Mar 20 20:19:17 localhost kernel: ppp0: hw csum failure Mar 20 20:19:17 localhost kernel: CPU: 1 PID: 0 Comm: swapper/1 Tainted: P OE 3.18.9-200.fc21.x86_64 #1 Mar 20 20:19:17 localhost kernel: Hardware name: System manufacturer P5Q-E/P5Q-E, BIOS 2101 04/06/2009 Mar 20 20:19:17 localhost kernel: 0000000000000000 2aa69f79e173cdac ffff88012fc83bc8 ffffffff8175b71c Mar 20 20:19:17 localhost kernel: 0000000000000000 ffff88009571c000 ffff88012fc83be8 ffffffff81644e02 Mar 20 20:19:17 localhost kernel: ffffffff81633520 ffff88011b7a8700 ffff88012fc83c28 ffffffff8163bf35 Mar 20 20:19:17 localhost kernel: Call Trace: Mar 20 20:19:17 localhost kernel: <IRQ> [<ffffffff8175b71c>] dump_stack+0x46/0x58 Mar 20 20:19:17 localhost kernel: [<ffffffff81644e02>] netdev_rx_csum_fault+0x42/0x50 Mar 20 20:19:17 localhost kernel: [<ffffffff81633520>] ? reqsk_fastopen_remove+0x150/0x150 Mar 20 20:19:17 localhost kernel: [<ffffffff8163bf35>] __skb_checksum_complete+0xc5/0xd0 Mar 20 20:19:17 localhost kernel: [<ffffffff816ae598>] tcp_v4_rcv+0x338/0x9a0 Mar 20 20:19:17 localhost kernel: [<ffffffff816875e0>] ? ip_rcv_finish+0x370/0x370 Mar 20 20:19:17 localhost kernel: [<ffffffff8167dea4>] ? nf_hook_slow+0x84/0x130 Mar 20 20:19:17 localhost kernel: [<ffffffff816875e0>] ? ip_rcv_finish+0x370/0x370 Mar 20 20:19:17 localhost kernel: [<ffffffff8168768e>] ip_local_deliver_finish+0xae/0x230 Mar 20 20:19:17 localhost kernel: [<ffffffff816879a8>] ip_local_deliver+0x48/0x80 Mar 20 20:19:17 localhost kernel: [<ffffffff816872f8>] ip_rcv_finish+0x88/0x370 Mar 20 20:19:17 localhost kernel: [<ffffffff81687c72>] ip_rcv+0x292/0x3a0 Mar 20 20:19:17 localhost kernel: [<ffffffff81647792>] __netif_receive_skb_core+0x582/0x820 Mar 20 20:19:17 localhost kernel: [<ffffffff81647a48>] __netif_receive_skb+0x18/0x60 Mar 20 20:19:17 localhost kernel: [<ffffffff81648712>] process_backlog+0xa2/0x150 Mar 20 20:19:17 localhost kernel: [<ffffffff81647eda>] net_rx_action+0x13a/0x240 Mar 20 20:19:17 localhost kernel: [<ffffffff8109d3ac>] __do_softirq+0x10c/0x2b0 Mar 20 20:19:17 localhost kernel: [<ffffffff8109d775>] irq_exit+0x125/0x130 Mar 20 20:19:17 localhost kernel: [<ffffffff81764dfa>] do_IRQ+0x5a/0xf0 Mar 20 20:19:17 localhost kernel: [<ffffffff81762c2d>] common_interrupt+0x6d/0x6d Mar 20 20:19:17 localhost kernel: <EOI> [<ffffffff810ff7a8>] ? hrtimer_start+0x18/0x20 Mar 20 20:19:17 localhost kernel: [<ffffffff8105ca56>] ? native_safe_halt+0x6/0x10 Mar 20 20:19:17 localhost kernel: [<ffffffff810f7443>] ? rcu_eqs_enter+0xa3/0xb0 Mar 20 20:19:17 localhost kernel: [<ffffffff8101e98f>] default_idle+0x1f/0xc0 Mar 20 20:19:17 localhost kernel: [<ffffffff8101f35f>] arch_cpu_idle+0xf/0x20 Mar 20 20:19:17 localhost kernel: [<ffffffff810da09c>] cpu_startup_entry+0x37c/0x3c0 Mar 20 20:19:17 localhost kernel: [<ffffffff81049dcf>] start_secondary+0x1af/0x1f0 Components: [root@dsk log]# uname -r 3.18.9-200.fc21.x86_64 [root@dsk log]# rpm -qva libreswan xl2tpd ppp xl2tpd-1.3.6-6.fc21.x86_64 ppp-2.4.7-6.fc21.x86_64 libreswan-3.12-1.fc21.x86_64
I have filed the bug report for upstream kernel: https://bugzilla.kernel.org/show_bug.cgi?id=95171
*********** MASS BUG UPDATE ************** We apologize for the inconvenience. There is a large number of bugs to go through and several of them have gone stale. Due to this, we are doing a mass bug update across all of the Fedora 21 kernel bugs. Fedora 21 has now been rebased to 3.19.5-200.fc21. Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel. If you have moved on to Fedora 22, and are still experiencing this issue, please change the version to Fedora 22. If you experience different issues, please open a new bug report for those.
The bug is still present in 3.19.5-200.fc21.x86_64
Kernel version 4.0.4-201.fc21.x86_64 fixed this bug (also see upstream info)