linux-stable.git/net/ipv6/sit.c, branch linux-5.9.y Linux kernel stable tree IPv6: Set SIT tunnel hard_header_len to zero 2020-11-18T18:22:31+00:00 Oliver Herms oliver.peter.herms@gmail.com 2020-11-03T10:41:33+00:00 5ec976b6216c041f989ef9f687523505fd33f226 [ Upstream commit 8ef9ba4d666614497a057d09b0a6eafc1e34eadf ] Due to the legacy usage of hard_header_len for SIT tunnels while already using infrastructure from net/ipv4/ip_tunnel.c the calculation of the path MTU in tnl_update_pmtu is incorrect. This leads to unnecessary creation of MTU exceptions for any flow going over a SIT tunnel. As SIT tunnels do not have a header themsevles other than their transport (L3, L2) headers we're leaving hard_header_len set to zero as tnl_update_pmtu is already taking care of the transport headers sizes. This will also help avoiding unnecessary IPv6 GC runs and spinlock contention seen when using SIT tunnels and for more than net.ipv6.route.gc_thresh flows. Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.") Signed-off-by: Oliver Herms <oliver.peter.herms@gmail.com> Acked-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/20201103104133.GA1573211@tws Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 8ef9ba4d666614497a057d09b0a6eafc1e34eadf ]

Due to the legacy usage of hard_header_len for SIT tunnels while
already using infrastructure from net/ipv4/ip_tunnel.c the
calculation of the path MTU in tnl_update_pmtu is incorrect.
This leads to unnecessary creation of MTU exceptions for any
flow going over a SIT tunnel.

As SIT tunnels do not have a header themsevles other than their
transport (L3, L2) headers we're leaving hard_header_len set to zero
as tnl_update_pmtu is already taking care of the transport headers
sizes.

This will also help avoiding unnecessary IPv6 GC runs and spinlock
contention seen when using SIT tunnels and for more than
net.ipv6.route.gc_thresh flows.

Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
Signed-off-by: Oliver Herms <oliver.peter.herms@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20201103104133.GA1573211@tws
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: sit: implement header_ops->parse_protocol for AF_PACKET 2020-06-30T19:29:39+00:00 Jason A. Donenfeld Jason@zx2c4.com 2020-06-30T01:06:24+00:00 75ea1f4773c09730bf8a364a367f6e7211484e12 Sit uses skb->protocol to determine packet type, and bails out if it's not set. For AF_PACKET injection, we need to support its call chain of: packet_sendmsg -> packet_snd -> packet_parse_headers -> dev_parse_header_protocol -> parse_protocol Without a valid parse_protocol, this returns zero, and sit rejects the skb. So, this wires up the ip_tunnel handler for layer 3 packets for that case. Reported-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Sit uses skb->protocol to determine packet type, and bails out if it's
not set. For AF_PACKET injection, we need to support its call chain of:

    packet_sendmsg -> packet_snd -> packet_parse_headers ->
      dev_parse_header_protocol -> parse_protocol

Without a valid parse_protocol, this returns zero, and sit rejects the
skb. So, this wires up the ip_tunnel handler for layer 3 packets for
that case.

Reported-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sit: impement ->ndo_tunnel_ctl 2020-05-19T22:45:12+00:00 Christoph Hellwig hch@lst.de 2020-05-19T13:03:16+00:00 f60fe2df931d6c0b41c3d4f8ec3f7a429f977a3f Implement the ->ndo_tunnel_ctl method, and use ip_tunnel_ioctl to handle userspace requests for the SIOCGETTUNNEL, SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net> 
Implement the ->ndo_tunnel_ctl method, and use ip_tunnel_ioctl to
handle userspace requests for the SIOCGETTUNNEL, SIOCADDTUNNEL,
SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
sit: refactor ipip6_tunnel_ioctl 2020-05-19T22:45:12+00:00 Christoph Hellwig hch@lst.de 2020-05-19T13:03:15+00:00 fd5d687b76b32543f6b2024ebe21f988ed1f8859 Split the ioctl handler into one function per command instead of having a all the logic sit in one giant switch statement. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net> 
Split the ioctl handler into one function per command instead of having
a all the logic sit in one giant switch statement.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
sit: do not confirm neighbor when do pmtu update 2019-12-25T06:28:55+00:00 Hangbin Liu liuhangbin@gmail.com 2019-12-22T02:51:15+00:00 4d42df46d6372ece4cb4279870b46c2ea7304a47 When do IPv6 tunnel PMTU update and calls __ip6_rt_update_pmtu() in the end, we should not call dst_confirm_neigh() as there is no two-way communication. v5: No change. v4: No change. v3: Do not remove dst_confirm_neigh, but add a new bool parameter in dst_ops.update_pmtu to control whether we should do neighbor confirm. Also split the big patch to small ones for each area. v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu. Reviewed-by: Guillaume Nault <gnault@redhat.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
When do IPv6 tunnel PMTU update and calls __ip6_rt_update_pmtu() in the end,
we should not call dst_confirm_neigh() as there is no two-way communication.

v5: No change.
v4: No change.
v3: Do not remove dst_confirm_neigh, but add a new bool parameter in
    dst_ops.update_pmtu to control whether we should do neighbor confirm.
    Also split the big patch to small ones for each area.
v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.

Reviewed-by: Guillaume Nault <gnault@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sit: use dst_cache in ipip6_tunnel_xmit 2019-07-14T19:15:28+00:00 Haishuang Yan yanhaishuang@cmss.chinamobile.com 2019-07-14T13:31:22+00:00 6e3d1bbbba55265d327e44a2d14de70462232853 Same as other ip tunnel, use dst_cache in xmit action to avoid unnecessary fib lookups. Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Same as other ip tunnel, use dst_cache in xmit action to avoid
unnecessary fib lookups.

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30T18:26:32+00:00 Thomas Gleixner tglx@linutronix.de 2019-05-27T06:55:01+00:00 2874c5fd284268364ece81a7bd936f3c8168e567 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vrf: sit mtu should not be updated when vrf netdev is the link 2019-05-07T19:19:19+00:00 Stephen Suryaputra ssuryaextr@gmail.com 2019-05-06T19:00:01+00:00 ff6ab32bd4e073976e4d8797b4d514a172cfe6cb VRF netdev mtu isn't typically set and have an mtu of 65536. When the link of a tunnel is set, the tunnel mtu is changed from 1480 to the link mtu minus tunnel header. In the case of VRF netdev is the link, then the tunnel mtu becomes 65516. So, fix it by not setting the tunnel mtu in this case. Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
VRF netdev mtu isn't typically set and have an mtu of 65536. When the
link of a tunnel is set, the tunnel mtu is changed from 1480 to the link
mtu minus tunnel header. In the case of VRF netdev is the link, then the
tunnel mtu becomes 65516. So, fix it by not setting the tunnel mtu in
this case.

Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv6: sit: reset ip header pointer in ipip6_rcv 2019-04-05T01:34:23+00:00 Lorenzo Bianconi lorenzo.bianconi@redhat.com 2019-04-04T14:37:53+00:00 bb9bd814ebf04f579be466ba61fc922625508807 ipip6 tunnels run iptunnel_pull_header on received skbs. This can determine the following use-after-free accessing iph pointer since the packet will be 'uncloned' running pskb_expand_head if it is a cloned gso skb (e.g if the packet has been sent though a veth device) [ 706.369655] BUG: KASAN: use-after-free in ipip6_rcv+0x1678/0x16e0 [sit] [ 706.449056] Read of size 1 at addr ffffe01b6bd855f5 by task ksoftirqd/1/= [ 706.669494] Hardware name: HPE ProLiant m400 Server/ProLiant m400 Server, BIOS U02 08/19/2016 [ 706.771839] Call trace: [ 706.801159] dump_backtrace+0x0/0x2f8 [ 706.845079] show_stack+0x24/0x30 [ 706.884833] dump_stack+0xe0/0x11c [ 706.925629] print_address_description+0x68/0x260 [ 706.982070] kasan_report+0x178/0x340 [ 707.025995] __asan_report_load1_noabort+0x30/0x40 [ 707.083481] ipip6_rcv+0x1678/0x16e0 [sit] [ 707.132623] tunnel64_rcv+0xd4/0x200 [tunnel4] [ 707.185940] ip_local_deliver_finish+0x3b8/0x988 [ 707.241338] ip_local_deliver+0x144/0x470 [ 707.289436] ip_rcv_finish+0x43c/0x14b0 [ 707.335447] ip_rcv+0x628/0x1138 [ 707.374151] __netif_receive_skb_core+0x1670/0x2600 [ 707.432680] __netif_receive_skb+0x28/0x190 [ 707.482859] process_backlog+0x1d0/0x610 [ 707.529913] net_rx_action+0x37c/0xf68 [ 707.574882] __do_softirq+0x288/0x1018 [ 707.619852] run_ksoftirqd+0x70/0xa8 [ 707.662734] smpboot_thread_fn+0x3a4/0x9e8 [ 707.711875] kthread+0x2c8/0x350 [ 707.750583] ret_from_fork+0x10/0x18 [ 707.811302] Allocated by task 16982: [ 707.854182] kasan_kmalloc.part.1+0x40/0x108 [ 707.905405] kasan_kmalloc+0xb4/0xc8 [ 707.948291] kasan_slab_alloc+0x14/0x20 [ 707.994309] __kmalloc_node_track_caller+0x158/0x5e0 [ 708.053902] __kmalloc_reserve.isra.8+0x54/0xe0 [ 708.108280] __alloc_skb+0xd8/0x400 [ 708.150139] sk_stream_alloc_skb+0xa4/0x638 [ 708.200346] tcp_sendmsg_locked+0x818/0x2b90 [ 708.251581] tcp_sendmsg+0x40/0x60 [ 708.292376] inet_sendmsg+0xf0/0x520 [ 708.335259] sock_sendmsg+0xac/0xf8 [ 708.377096] sock_write_iter+0x1c0/0x2c0 [ 708.424154] new_sync_write+0x358/0x4a8 [ 708.470162] __vfs_write+0xc4/0xf8 [ 708.510950] vfs_write+0x12c/0x3d0 [ 708.551739] ksys_write+0xcc/0x178 [ 708.592533] __arm64_sys_write+0x70/0xa0 [ 708.639593] el0_svc_handler+0x13c/0x298 [ 708.686646] el0_svc+0x8/0xc [ 708.739019] Freed by task 17: [ 708.774597] __kasan_slab_free+0x114/0x228 [ 708.823736] kasan_slab_free+0x10/0x18 [ 708.868703] kfree+0x100/0x3d8 [ 708.905320] skb_free_head+0x7c/0x98 [ 708.948204] skb_release_data+0x320/0x490 [ 708.996301] pskb_expand_head+0x60c/0x970 [ 709.044399] __iptunnel_pull_header+0x3b8/0x5d0 [ 709.098770] ipip6_rcv+0x41c/0x16e0 [sit] [ 709.146873] tunnel64_rcv+0xd4/0x200 [tunnel4] [ 709.200195] ip_local_deliver_finish+0x3b8/0x988 [ 709.255596] ip_local_deliver+0x144/0x470 [ 709.303692] ip_rcv_finish+0x43c/0x14b0 [ 709.349705] ip_rcv+0x628/0x1138 [ 709.388413] __netif_receive_skb_core+0x1670/0x2600 [ 709.446943] __netif_receive_skb+0x28/0x190 [ 709.497120] process_backlog+0x1d0/0x610 [ 709.544169] net_rx_action+0x37c/0xf68 [ 709.589131] __do_softirq+0x288/0x1018 [ 709.651938] The buggy address belongs to the object at ffffe01b6bd85580 which belongs to the cache kmalloc-1024 of size 1024 [ 709.804356] The buggy address is located 117 bytes inside of 1024-byte region [ffffe01b6bd85580, ffffe01b6bd85980) [ 709.946340] The buggy address belongs to the page: [ 710.003824] page:ffff7ff806daf600 count:1 mapcount:0 mapping:ffffe01c4001f600 index:0x0 [ 710.099914] flags: 0xfffff8000000100(slab) [ 710.149059] raw: 0fffff8000000100 dead000000000100 dead000000000200 ffffe01c4001f600 [ 710.242011] raw: 0000000000000000 0000000000380038 00000001ffffffff 0000000000000000 [ 710.334966] page dumped because: kasan: bad access detected Fix it resetting iph pointer after iptunnel_pull_header Fixes: a09a4c8dd1ec ("tunnels: Remove encapsulation offloads on decap") Tested-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
ipip6 tunnels run iptunnel_pull_header on received skbs. This can
determine the following use-after-free accessing iph pointer since
the packet will be 'uncloned' running pskb_expand_head if it is a
cloned gso skb (e.g if the packet has been sent though a veth device)

[  706.369655] BUG: KASAN: use-after-free in ipip6_rcv+0x1678/0x16e0 [sit]
[  706.449056] Read of size 1 at addr ffffe01b6bd855f5 by task ksoftirqd/1/=
[  706.669494] Hardware name: HPE ProLiant m400 Server/ProLiant m400 Server, BIOS U02 08/19/2016
[  706.771839] Call trace:
[  706.801159]  dump_backtrace+0x0/0x2f8
[  706.845079]  show_stack+0x24/0x30
[  706.884833]  dump_stack+0xe0/0x11c
[  706.925629]  print_address_description+0x68/0x260
[  706.982070]  kasan_report+0x178/0x340
[  707.025995]  __asan_report_load1_noabort+0x30/0x40
[  707.083481]  ipip6_rcv+0x1678/0x16e0 [sit]
[  707.132623]  tunnel64_rcv+0xd4/0x200 [tunnel4]
[  707.185940]  ip_local_deliver_finish+0x3b8/0x988
[  707.241338]  ip_local_deliver+0x144/0x470
[  707.289436]  ip_rcv_finish+0x43c/0x14b0
[  707.335447]  ip_rcv+0x628/0x1138
[  707.374151]  __netif_receive_skb_core+0x1670/0x2600
[  707.432680]  __netif_receive_skb+0x28/0x190
[  707.482859]  process_backlog+0x1d0/0x610
[  707.529913]  net_rx_action+0x37c/0xf68
[  707.574882]  __do_softirq+0x288/0x1018
[  707.619852]  run_ksoftirqd+0x70/0xa8
[  707.662734]  smpboot_thread_fn+0x3a4/0x9e8
[  707.711875]  kthread+0x2c8/0x350
[  707.750583]  ret_from_fork+0x10/0x18

[  707.811302] Allocated by task 16982:
[  707.854182]  kasan_kmalloc.part.1+0x40/0x108
[  707.905405]  kasan_kmalloc+0xb4/0xc8
[  707.948291]  kasan_slab_alloc+0x14/0x20
[  707.994309]  __kmalloc_node_track_caller+0x158/0x5e0
[  708.053902]  __kmalloc_reserve.isra.8+0x54/0xe0
[  708.108280]  __alloc_skb+0xd8/0x400
[  708.150139]  sk_stream_alloc_skb+0xa4/0x638
[  708.200346]  tcp_sendmsg_locked+0x818/0x2b90
[  708.251581]  tcp_sendmsg+0x40/0x60
[  708.292376]  inet_sendmsg+0xf0/0x520
[  708.335259]  sock_sendmsg+0xac/0xf8
[  708.377096]  sock_write_iter+0x1c0/0x2c0
[  708.424154]  new_sync_write+0x358/0x4a8
[  708.470162]  __vfs_write+0xc4/0xf8
[  708.510950]  vfs_write+0x12c/0x3d0
[  708.551739]  ksys_write+0xcc/0x178
[  708.592533]  __arm64_sys_write+0x70/0xa0
[  708.639593]  el0_svc_handler+0x13c/0x298
[  708.686646]  el0_svc+0x8/0xc

[  708.739019] Freed by task 17:
[  708.774597]  __kasan_slab_free+0x114/0x228
[  708.823736]  kasan_slab_free+0x10/0x18
[  708.868703]  kfree+0x100/0x3d8
[  708.905320]  skb_free_head+0x7c/0x98
[  708.948204]  skb_release_data+0x320/0x490
[  708.996301]  pskb_expand_head+0x60c/0x970
[  709.044399]  __iptunnel_pull_header+0x3b8/0x5d0
[  709.098770]  ipip6_rcv+0x41c/0x16e0 [sit]
[  709.146873]  tunnel64_rcv+0xd4/0x200 [tunnel4]
[  709.200195]  ip_local_deliver_finish+0x3b8/0x988
[  709.255596]  ip_local_deliver+0x144/0x470
[  709.303692]  ip_rcv_finish+0x43c/0x14b0
[  709.349705]  ip_rcv+0x628/0x1138
[  709.388413]  __netif_receive_skb_core+0x1670/0x2600
[  709.446943]  __netif_receive_skb+0x28/0x190
[  709.497120]  process_backlog+0x1d0/0x610
[  709.544169]  net_rx_action+0x37c/0xf68
[  709.589131]  __do_softirq+0x288/0x1018

[  709.651938] The buggy address belongs to the object at ffffe01b6bd85580
                which belongs to the cache kmalloc-1024 of size 1024
[  709.804356] The buggy address is located 117 bytes inside of
                1024-byte region [ffffe01b6bd85580, ffffe01b6bd85980)
[  709.946340] The buggy address belongs to the page:
[  710.003824] page:ffff7ff806daf600 count:1 mapcount:0 mapping:ffffe01c4001f600 index:0x0
[  710.099914] flags: 0xfffff8000000100(slab)
[  710.149059] raw: 0fffff8000000100 dead000000000100 dead000000000200 ffffe01c4001f600
[  710.242011] raw: 0000000000000000 0000000000380038 00000001ffffffff 0000000000000000
[  710.334966] page dumped because: kasan: bad access detected

Fix it resetting iph pointer after iptunnel_pull_header

Fixes: a09a4c8dd1ec ("tunnels: Remove encapsulation offloads on decap")
Tested-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: sit: fix UBSAN Undefined behaviour in check_6rd 2019-03-11T17:32:45+00:00 Miaohe Lin linmiaohe@huawei.com 2019-03-11T08:29:32+00:00 a843dc4ebaecd15fca1f4d35a97210f72ea1473b In func check_6rd,tunnel->ip6rd.relay_prefixlen may equal to 32,so UBSAN complain about it. UBSAN: Undefined behaviour in net/ipv6/sit.c:781:47 shift exponent 32 is too large for 32-bit type 'unsigned int' CPU: 6 PID: 20036 Comm: syz-executor.0 Not tainted 4.19.27 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xca/0x13e lib/dump_stack.c:113 ubsan_epilogue+0xe/0x81 lib/ubsan.c:159 __ubsan_handle_shift_out_of_bounds+0x293/0x2e8 lib/ubsan.c:425 check_6rd.constprop.9+0x433/0x4e0 net/ipv6/sit.c:781 try_6rd net/ipv6/sit.c:806 [inline] ipip6_tunnel_xmit net/ipv6/sit.c:866 [inline] sit_tunnel_xmit+0x141c/0x2720 net/ipv6/sit.c:1033 __netdev_start_xmit include/linux/netdevice.h:4300 [inline] netdev_start_xmit include/linux/netdevice.h:4309 [inline] xmit_one net/core/dev.c:3243 [inline] dev_hard_start_xmit+0x17c/0x780 net/core/dev.c:3259 __dev_queue_xmit+0x1656/0x2500 net/core/dev.c:3829 neigh_output include/net/neighbour.h:501 [inline] ip6_finish_output2+0xa36/0x2290 net/ipv6/ip6_output.c:120 ip6_finish_output+0x3e7/0xa20 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x1e2/0x720 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] ip6_local_out+0x99/0x170 net/ipv6/output_core.c:176 ip6_send_skb+0x9d/0x2f0 net/ipv6/ip6_output.c:1697 ip6_push_pending_frames+0xc0/0x100 net/ipv6/ip6_output.c:1717 rawv6_push_pending_frames net/ipv6/raw.c:616 [inline] rawv6_sendmsg+0x2435/0x3530 net/ipv6/raw.c:946 inet_sendmsg+0xf8/0x5c0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xc8/0x110 net/socket.c:631 ___sys_sendmsg+0x6cf/0x890 net/socket.c:2114 __sys_sendmsg+0xf0/0x1b0 net/socket.c:2152 do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Signed-off-by: linmiaohe <linmiaohe@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
In func check_6rd,tunnel->ip6rd.relay_prefixlen may equal to
32,so UBSAN complain about it.

UBSAN: Undefined behaviour in net/ipv6/sit.c:781:47
shift exponent 32 is too large for 32-bit type 'unsigned int'
CPU: 6 PID: 20036 Comm: syz-executor.0 Not tainted 4.19.27 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1
04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xca/0x13e lib/dump_stack.c:113
ubsan_epilogue+0xe/0x81 lib/ubsan.c:159
__ubsan_handle_shift_out_of_bounds+0x293/0x2e8 lib/ubsan.c:425
check_6rd.constprop.9+0x433/0x4e0 net/ipv6/sit.c:781
try_6rd net/ipv6/sit.c:806 [inline]
ipip6_tunnel_xmit net/ipv6/sit.c:866 [inline]
sit_tunnel_xmit+0x141c/0x2720 net/ipv6/sit.c:1033
__netdev_start_xmit include/linux/netdevice.h:4300 [inline]
netdev_start_xmit include/linux/netdevice.h:4309 [inline]
xmit_one net/core/dev.c:3243 [inline]
dev_hard_start_xmit+0x17c/0x780 net/core/dev.c:3259
__dev_queue_xmit+0x1656/0x2500 net/core/dev.c:3829
neigh_output include/net/neighbour.h:501 [inline]
ip6_finish_output2+0xa36/0x2290 net/ipv6/ip6_output.c:120
ip6_finish_output+0x3e7/0xa20 net/ipv6/ip6_output.c:154
NF_HOOK_COND include/linux/netfilter.h:278 [inline]
ip6_output+0x1e2/0x720 net/ipv6/ip6_output.c:171
dst_output include/net/dst.h:444 [inline]
ip6_local_out+0x99/0x170 net/ipv6/output_core.c:176
ip6_send_skb+0x9d/0x2f0 net/ipv6/ip6_output.c:1697
ip6_push_pending_frames+0xc0/0x100 net/ipv6/ip6_output.c:1717
rawv6_push_pending_frames net/ipv6/raw.c:616 [inline]
rawv6_sendmsg+0x2435/0x3530 net/ipv6/raw.c:946
inet_sendmsg+0xf8/0x5c0 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg+0xc8/0x110 net/socket.c:631
___sys_sendmsg+0x6cf/0x890 net/socket.c:2114
__sys_sendmsg+0xf0/0x1b0 net/socket.c:2152
do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: linmiaohe <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>