IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready ip (3959) used greatest stack depth: 24432 bytes left IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready hrtimer: interrupt took 11767 ns BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 IP: [] sock_hold include/net/sock.h:589 [inline] IP: [] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809 PGD 1d81be067 PUD 1ceb4d067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 4244 Comm: syz-executor0 Not tainted 4.4.151-ge917467 #84 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d7126000 task.stack: ffff8801d6ee0000 RIP: 0010:[] [] sock_hold include/net/sock.h:589 [inline] RIP: 0010:[] [] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809 RSP: 0018:ffff8801d6ee7b48 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8801da25a500 RCX: 0000000000000006 RDX: 1ffff1003b44b4d0 RSI: ffffffff835a4543 RDI: ffff8801da25a680 RBP: ffff8801d6ee7bb8 R08: ffff8801d7126900 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8463a140 R12: ffff8801da25a328 R13: ffff8801d6ee7cd0 R14: ffff8801da25a280 R15: ffffffff835a3170 FS: 00007f0f64b7e700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000080 CR3: 00000001cd45e000 CR4: 00000000001606f0 Stack: ffffffff81140a6a ffff8801da25a520 ffff8801da25a3d8 ffff8801da25a290 ffffffff838cba90 ffff8801da25a330 ffff8801da25a3d0 ffff8801da25a5e0 ffff880100000000 ffff8801d6eccc80 0000000000000000 ffff8801d6ecccb0 Call Trace: [] pppol2tp_connect+0x10f0/0x1910 net/l2tp/l2tp_ppp.c:725 [] SYSC_connect+0x1b8/0x300 net/socket.c:1558 [] SyS_connect+0x24/0x30 net/socket.c:1539 [] entry_SYSCALL_64_fastpath+0x22/0x9e Code: 00 00 48 8d bb 80 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 36 06 00 00 48 8b 83 80 01 00 00 ff 80 80 00 00 00 48 8d 43 20 48 89 c7 48 89 45 b0 e8 f1 13 RIP [] sock_hold include/net/sock.h:589 [inline] RIP [] l2tp_session_create+0x948/0x1030 net/l2tp/l2tp_core.c:1809 RSP CR2: 0000000000000080 ---[ end trace ce9250db613183d4 ]---