------------[ cut here ]------------
kernel BUG at net/l2tp/l2tp_ppp.c:176!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 6449 Comm: kworker/u4:9 Not tainted 4.15.0-rc8+ #199
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: kkcmd kcm_tx_work
RIP: 0010:pppol2tp_sock_to_session net/l2tp/l2tp_ppp.c:176 [inline]
RIP: 0010:pppol2tp_sendmsg+0x512/0x670 net/l2tp/l2tp_ppp.c:304
RSP: 0018:ffff8801c2dc7128 EFLAGS: 00010293
RAX: ffff8801c15d0100 RBX: ffff8801c46b2e00 RCX: ffffffff85069002
RDX: 0000000000000000 RSI: ffff8801c2dc7288 RDI: ffff8801c46b31e0
RBP: ffff8801c2dc7198 R08: 0000000000000000 R09: 1ffff100385b8db5
------------[ cut here ]------------
kernel BUG at net/l2tp/l2tp_ppp.c:176!
R10: 0000000000000003 R11: 0000000000000003 R12: ffff8801bba15600
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001000 CR3: 0000000006822004 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:640
 kernel_sendmsg+0x47/0x60 net/socket.c:648
 sock_no_sendpage+0x1cc/0x280 net/core/sock.c:2581
 kernel_sendpage+0xbf/0xe0 net/socket.c:3360
 kcm_write_msgs+0x404/0x1b80 net/kcm/kcmsock.c:646
 kcm_tx_work+0x2e/0x190 net/kcm/kcmsock.c:731
 process_one_work+0xbbf/0x1b10 kernel/workqueue.c:2113
 worker_thread+0x223/0x1990 kernel/workqueue.c:2247
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:541
Code: 75 a2 69 fc 48 8b 7d d0 e8 fc 23 55 fd 84 c0 74 0d e8 63 a2 69 fc 48 89 df e8 0b 66 2b ff 41 bd f7 ff ff ff eb 86 e8 4e a2 69 fc <0f> 0b 41 bd 95 ff ff ff e9 74 ff ff ff e8 6c 95 a1 fc e9 77 fb 
RIP: pppol2tp_sock_to_session net/l2tp/l2tp_ppp.c:176 [inline] RSP: ffff8801c2dc7128
RIP: pppol2tp_sendmsg+0x512/0x670 net/l2tp/l2tp_ppp.c:304 RSP: ffff8801c2dc7128
invalid opcode: 0000 [#2] SMP KASAN
---[ end trace 8d605c7b7f9b7e31 ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 21143 Comm: syz-executor4 Tainted: G      D          4.15.0-rc8+ #199
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:pppol2tp_sock_to_session net/l2tp/l2tp_ppp.c:176 [inline]
RIP: 0010:pppol2tp_ioctl+0x582/0x730 net/l2tp/l2tp_ppp.c:1229
RSP: 0018:ffff8801c7bbfbd8 EFLAGS: 00010212
RAX: 0000000000010000 RBX: ffff8801c46b2e00 RCX: ffffffff85069c42
RDX: 0000000000000055 RSI: ffffc90004d60000 RDI: ffff8801c46b2e80
RBP: ffff8801c7bbfcc8 R08: 0000000000000000 R09: 0000000000000000
R10: ffff8801c7bbfb78 R11: ffff8801c46b2f10 R12: 1ffff10038f77f80
R13: ffff8801bba15600 R14: ffff8801c7bbfca0 R15: ffffffff850696c0
FS:  00007f6e29d85700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020009000 CR3: 00000001d04be006 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 pppox_ioctl+0x1c7/0x250 drivers/net/ppp/pppox.c:97
 sock_do_ioctl+0x65/0xb0 net/socket.c:958
 sock_ioctl+0x2c2/0x440 net/socket.c:1055
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x452ee9
RSP: 002b:00007f6e29d84c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000071c010 RCX: 0000000000452ee9
RDX: 0000000020009000 RSI: 0000000040047459 RDI: 0000000000000016
RBP: 00000000000004cb R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f63a8
R13: 00000000ffffffff R14: 00007f6e29d856d4 R15: 0000000000000019
Code: 00 89 85 30 ff ff ff e8 bd 17 55 fd 84 c0 0f 84 a1 fe ff ff e8 20 96 69 fc 4c 89 f7 e8 68 1c ff ff e9 8f fe ff ff e8 0e 96 69 fc <0f> 0b e8 07 96 69 fc 48 8b bd 20 ff ff ff e8 8b 17 55 fd 84 c0 
RIP: pppol2tp_sock_to_session net/l2tp/l2tp_ppp.c:176 [inline] RSP: ffff8801c7bbfbd8
RIP: pppol2tp_ioctl+0x582/0x730 net/l2tp/l2tp_ppp.c:1229 RSP: ffff8801c7bbfbd8
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..