BUG: unable to handle page fault for address: ADDR

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    80f23212 Merge git://git.kernel.org/pub/scm/linux/kernel/g..
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=112de0d8a00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=40a58b399941db7e
dashboard link: https://syzkaller.appspot.com/bug?extid=208b9694ae6aee1c7197
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+208b9694ae6aee1c7197@xxxxxxxxxxxxxxxxxxxxxxxxx

New replicast peer: 172.20.20.187
BUG: unable to handle page fault for address: ffffde202758ca0b
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 17591 Comm: syz-executor.3 Not tainted 5.1.0+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:iptunnel_xmit_stats include/net/ip_tunnels.h:444 [inline]
RIP: 0010:iptunnel_xmit+0x6e5/0x970 net/ipv4/ip_tunnel_core.c:94
Code: c1 e9 03 80 3c 11 00 0f 85 72 02 00 00 48 03 1c c5 60 70 6e 88 48 b8  
00 00 00 00 00 fc ff df 48 8d 7b 18 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f  
85 5d 02 00 00 48 8d 7b 10 4d 63 e4 48 b8 00 00 00
RSP: 0018:ffff8880a0fb7008 EFLAGS: 00010a02
RAX: dffffc0000000000 RBX: ffff11013ac65040 RCX: 1ffffffff10dce0c
RDX: 1fffe2202758ca0b RSI: ffffffff83344b4c RDI: ffff11013ac65058
RBP: ffff8880a0fb7068 R08: ffff888059df8140 R09: ffffed1015d06be0
R10: ffffed1015d06bdf R11: ffff8880ae835efb R12: 00000000000000fc
R13: ffff88806bbfec40 R14: ffff88806a6a3714 R15: ffff8880a097a8c0
FS:  00007fcf84ffc700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffde202758ca0b CR3: 00000000970bb000 CR4: 00000000001406f0
Call Trace:
 udp_tunnel_xmit_skb+0x236/0x310 net/ipv4/udp_tunnel.c:191
 tipc_udp_xmit.isra.0+0x805/0xcc0 net/tipc/udp_media.c:181
 tipc_udp_send_msg+0x295/0x4a0 net/tipc/udp_media.c:247
 tipc_bearer_xmit_skb+0x172/0x360 net/tipc/bearer.c:503
 tipc_enable_bearer+0xac4/0xd20 net/tipc/bearer.c:328
 __tipc_nl_bearer_enable+0x2de/0x3a0 net/tipc/bearer.c:899
 tipc_nl_bearer_enable+0x23/0x40 net/tipc/bearer.c:907
 genl_family_rcv_msg+0x753/0xf90 net/netlink/genetlink.c:629
 genl_rcv_msg+0xca/0x16c net/netlink/genetlink.c:654
 netlink_rcv_skb+0x17a/0x460 net/netlink/af_netlink.c:2486
 genl_rcv+0x29/0x40 net/netlink/genetlink.c:665
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x536/0x720 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1926
 sock_sendmsg_nosec net/socket.c:660 [inline]
 sock_sendmsg+0x12e/0x170 net/socket.c:671
 ___sys_sendmsg+0x81d/0x960 net/socket.c:2292
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2330
 __do_sys_sendmsg net/socket.c:2339 [inline]
 __se_sys_sendmsg net/socket.c:2337 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2337
 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458da9
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7  
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fcf84ffbc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458da9
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcf84ffc6d4
R13: 00000000004c6449 R14: 00000000004dad18 R15: 00000000ffffffff
Modules linked in:
CR2: ffffde202758ca0b
---[ end trace 7b8973c639719d58 ]---
RIP: 0010:iptunnel_xmit_stats include/net/ip_tunnels.h:444 [inline]
RIP: 0010:iptunnel_xmit+0x6e5/0x970 net/ipv4/ip_tunnel_core.c:94
Code: c1 e9 03 80 3c 11 00 0f 85 72 02 00 00 48 03 1c c5 60 70 6e 88 48 b8  
00 00 00 00 00 fc ff df 48 8d 7b 18 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f  
85 5d 02 00 00 48 8d 7b 10 4d 63 e4 48 b8 00 00 00
RSP: 0018:ffff8880a0fb7008 EFLAGS: 00010a02
RAX: dffffc0000000000 RBX: ffff11013ac65040 RCX: 1ffffffff10dce0c
RDX: 1fffe2202758ca0b RSI: ffffffff83344b4c RDI: ffff11013ac65058
RBP: ffff8880a0fb7068 R08: ffff888059df8140 R09: ffffed1015d06be0
R10: ffffed1015d06bdf R11: ffff8880ae835efb R12: 00000000000000fc
R13: ffff88806bbfec40 R14: ffff88806a6a3714 R15: ffff8880a097a8c0
FS:  00007fcf84ffc700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffde202758ca0b CR3: 00000000970bb000 CR4: 00000000001406f0


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