[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   13.118038] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   18.565818] random: sshd: uninitialized urandom read (32 bytes read)
[   18.863828] random: sshd: uninitialized urandom read (32 bytes read)
[   19.351812] random: sshd: uninitialized urandom read (32 bytes read)
[   44.384606] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.0.23' (ECDSA) to the list of known hosts.
[   49.944186] random: sshd: uninitialized urandom read (32 bytes read)
2018/08/23 13:19:46 parsed 1 programs
[   51.030161] random: cc1: uninitialized urandom read (8 bytes read)
2018/08/23 13:19:47 executed programs: 0
[   52.184170] IPVS: Creating netns size=2536 id=1
[   52.306219] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready
[   52.318011] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready
[   52.360218] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready
[   52.371936] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready
[   52.416143] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready
[   52.428367] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready
[   52.440925] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready
[   52.455174] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
[   52.985463] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
[   53.012710] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
[   53.018955] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
[   53.026244] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
[   53.258014] hrtimer: interrupt took 14458 ns
[   53.317017] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
[   53.325523] IP: [<ffffffff836c8e30>] l2tp_session_create+0xc60/0x16f0
[   53.332197] PGD 1d76b9067 [   53.334852] PUD 1d7ac4067 
PMD 0 [   53.338605] 
[   53.340233] Oops: 0002 [#1] PREEMPT SMP KASAN
[   53.344698] Dumping ftrace buffer:
[   53.348209]    (ftrace buffer empty)
[   53.351891] Modules linked in:
[   53.355419] CPU: 0 PID: 4116 Comm: syz-executor0 Not tainted 4.9.123-g8dd3fc2 #79
[   53.363011] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   53.372359] task: ffff8801d78e4800 task.stack: ffff8801d74e0000
[   53.378480] RIP: 0010:[<ffffffff836c8e30>]  [<ffffffff836c8e30>] l2tp_session_create+0xc60/0x16f0
[   53.387592] RSP: 0018:ffff8801d74e7ac0  EFLAGS: 00010246
[   53.393012] RAX: 0000000000000000 RBX: ffff8801cb141680 RCX: 1ffff1003af1ca1d
[   53.400470] RDX: 1ffff10039628260 RSI: ffff8801d78e50c8 RDI: ffff8801cb141300
[   53.407789] RBP: ffff8801d74e7b60 R08: ffff8801d78e50e8 R09: 0000000000000000
[   53.415210] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801cb1411d8
[   53.422525] R13: 0000000000000000 R14: ffff8801cb141180 R15: ffff8801d74e7c78
[   53.429779] FS:  00007f125b734700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
[   53.438171] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   53.444029] CR2: 0000000000000080 CR3: 00000001d6ed2000 CR4: 00000000001606f0
[   53.451284] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   53.458606] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   53.465852] Stack:
[   53.467972]  0000000000000201 ffffffff836ca141 ffff8801d74e7ae0 ffffffff81237f0d
[   53.475956]  ffff8801cb141180 ffff8801cb1417d8 ffff8801cb1411d8 ffff8801cb1417d0
[   53.484001]  ffff8801cb141730 ffff8801cb1411a0 0000000000000000 0000000000000000
[   53.492048] Call Trace:
[   53.494609]  [<ffffffff836ca141>] ? l2tp_session_get+0x1d1/0x790
[   53.500798]  [<ffffffff81237f0d>] ? trace_hardirqs_on+0xd/0x10
[   53.506746]  [<ffffffff836cdfe7>] pppol2tp_connect+0x10d7/0x18f0
[   53.512868]  [<ffffffff836ccf10>] ? pppol2tp_seq_show+0xc30/0xc30
[   53.519080]  [<ffffffff81f2110b>] ? check_preemption_disabled+0x3b/0x170
[   53.525896]  [<ffffffff83a02629>] ? retint_kernel+0x2d/0x2d
[   53.531680]  [<ffffffff81cf90cf>] ? security_socket_connect+0x8f/0xc0
[   53.538254]  [<ffffffff8301e958>] SYSC_connect+0x1b8/0x300
[   53.543853]  [<ffffffff8301e7a0>] ? SYSC_bind+0x280/0x280
[   53.549662]  [<ffffffff812db710>] ? do_futex+0x17c0/0x17c0
[   53.555262]  [<ffffffff83a02629>] ? retint_kernel+0x2d/0x2d
[   53.561105]  [<ffffffff812db710>] ? do_futex+0x17c0/0x17c0
[   53.566705]  [<ffffffff83021224>] SyS_connect+0x24/0x30
[   53.572047]  [<ffffffff83021200>] ? SyS_accept+0x30/0x30
[   53.577473]  [<ffffffff81006316>] do_syscall_64+0x1a6/0x490
[   53.583158]  [<ffffffff83a01c93>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
[   53.590050] Code: 00 00 49 8d be 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 7b 09 00 00 49 8b 86 80 01 00 00 <f0> ff 80 80 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 55 d0 
[   53.617194] RIP  [<ffffffff836c8e30>] l2tp_session_create+0xc60/0x16f0
[   53.624029]  RSP <ffff8801d74e7ac0>
[   53.627631] CR2: 0000000000000080
[   53.631953] ---[ end trace 3eac39cdfa31522e ]---
[   53.636714] Kernel panic - not syncing: Fatal exception
[   53.642392] Dumping ftrace buffer:
[   53.645912]    (ftrace buffer empty)
[   53.649595] Kernel Offset: disabled
[   53.653197] Rebooting in 86400 seconds..