[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.066840] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.766510] random: sshd: uninitialized urandom read (32 bytes read, 35 bits of entropy available) [ 20.987224] random: sshd: uninitialized urandom read (32 bytes read, 35 bits of entropy available) [ 21.640476] random: sshd: uninitialized urandom read (32 bytes read, 65 bits of entropy available) [ 37.361960] random: sshd: uninitialized urandom read (32 bytes read, 74 bits of entropy available) Warning: Permanently added '10.128.0.53' (ECDSA) to the list of known hosts. [ 42.872017] random: sshd: uninitialized urandom read (32 bytes read, 76 bits of entropy available) executing program executing program [ 43.093214] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [ 43.101439] IP: [] l2tp_session_free+0x11c/0x200 [ 43.107868] PGD 1d7348067 PUD 1cdaef067 PMD 0 [ 43.112779] Oops: 0002 [#1] PREEMPT SMP KASAN [ 43.117857] Dumping ftrace buffer: [ 43.121369] (ftrace buffer empty) [ 43.125061] Modules linked in: [ 43.128343] CPU: 1 PID: 1805 Comm: kworker/1:2 Not tainted 4.4.150-g5541782 #83 [ 43.135772] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.145124] Workqueue: sock_diag_events sock_diag_broadcast_destroy_work [ 43.152050] task: ffff8800b6836000 task.stack: ffff8801d4210000 [ 43.158077] RIP: 0010:[] [] l2tp_session_free+0x11c/0x200 [ 43.166949] RSP: 0018:ffff8801d4217b28 EFLAGS: 00010246 [ 43.172368] RAX: dffffc0000000000 RBX: ffff8800b1f1a780 RCX: 0000000000000000 [ 43.179616] RDX: 1ffff100163e3610 RSI: ffffffff835a5991 RDI: ffff8800b1f1b080 [ 43.186861] RBP: ffff8801d4217b48 R08: ffff8800b6836928 R09: 0000000000000000 [ 43.194101] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800b1f1af00 [ 43.201342] R13: ffff8800b1f1a788 R14: 0000000000000000 R15: ffff8800b1f1af58 [ 43.208584] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 43.216786] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 43.222640] CR2: 0000000000000080 CR3: 00000001d3b8f000 CR4: 00000000001606f0 [ 43.229888] Stack: [ 43.232006] ffff8800b1f1a828 dffffc0000000000 ffff8800b1f1a780 ffffffff835af470 [ 43.239991] ffff8801d4217ba0 ffffffff835a7dc9 ffff8800b1f1afd8 ffffed00163e35eb [ 43.248026] ffff8800b1f1af58 ffff8800b1f1af20 ffff8800b1f1af00 ffff8801ce3d8000 [ 43.256044] Call Trace: [ 43.258679] [] ? pppol2tp_session_destruct+0x110/0x110 [ 43.265695] [] l2tp_tunnel_closeall+0x2b9/0x350 [ 43.271999] [] l2tp_tunnel_destruct+0x2f2/0x590 [ 43.278291] [] ? l2tp_tunnel_destruct+0x1aa/0x590 [ 43.284753] [] ? l2tp_tunnel_del_work+0x460/0x460 [ 43.291361] [] sk_destruct+0x4c/0x4c0 [ 43.296788] [] sock_diag_broadcast_destroy_work+0x21a/0x390 [ 43.304122] [] process_one_work+0x7df/0x1600 [ 43.310162] [] ? process_one_work+0x6fa/0x1600 [ 43.316379] [] ? cancel_delayed_work_sync+0x20/0x20 [ 43.323054] [] worker_thread+0xd9/0xfc0 [ 43.328668] [] ? _raw_spin_unlock_irqrestore+0x5a/0x70 [ 43.335572] [] kthread+0x268/0x300 [ 43.340731] [] ? process_one_work+0x1600/0x1600 [ 43.347020] [] ? kthread_create_on_node+0x400/0x400 [ 43.353657] [] ? __schedule+0x7a0/0x1d70 [ 43.359338] [] ? kthread_create_on_node+0x400/0x400 [ 43.365977] [] ret_from_fork+0x55/0x80 [ 43.371484] [] ? kthread_create_on_node+0x400/0x400 [ 43.378185] Code: 49 8d bc 24 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 d0 00 00 00 4d 8b b4 24 80 01 00 00 41 ff 8e 80 00 00 00 74 64 e8 15 eb da fd e8 10 eb da fd 4c [ 43.405103] RIP [] l2tp_session_free+0x11c/0x200 [ 43.411597] RSP [ 43.415192] CR2: 0000000000000080 [ 43.418617] ---[ end trace 954b4d16b6b65573 ]--- [ 43.423344] Kernel panic - not syncing: Fatal exception [ 43.428985] Dumping ftrace buffer: [ 43.432502] (ftrace buffer empty) [ 43.436192] Kernel Offset: disabled [ 43.439806] Rebooting in 86400 seconds..