[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 23.941460] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 26.329752] random: sshd: uninitialized urandom read (32 bytes read, 41 bits of entropy available) [ 26.763689] random: sshd: uninitialized urandom read (32 bytes read, 41 bits of entropy available) [ 27.517360] random: sshd: uninitialized urandom read (32 bytes read, 72 bits of entropy available) [ 50.605249] random: sshd: uninitialized urandom read (32 bytes read, 87 bits of entropy available) Warning: Permanently added '10.128.10.29' (ECDSA) to the list of known hosts. [ 56.255194] random: sshd: uninitialized urandom read (32 bytes read, 90 bits of entropy available) 2018/08/22 16:03:33 parsed 1 programs [ 57.506745] random: cc1: uninitialized urandom read (8 bytes read, 92 bits of entropy available) 2018/08/22 16:03:35 executed programs: 0 [ 59.062403] IPVS: Creating netns size=2552 id=1 [ 59.298846] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 59.312809] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 59.395662] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 59.410711] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready [ 59.491312] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 59.506024] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 59.522559] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 59.539914] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 59.582686] ip (3970) used greatest stack depth: 24432 bytes left [ 60.274906] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 60.313884] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 60.627454] hrtimer: interrupt took 13124 ns [ 60.632695] l2tp_core: tunl 4: sockfd_lookup(fd=6) returned -9 [ 60.667251] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [ 60.675619] IP: [] l2tp_session_create+0x948/0x1030 [ 60.682444] PGD b9025067 PUD b994f067 PMD 0 [ 60.687394] Oops: 0002 [#1] PREEMPT SMP KASAN [ 60.692436] Dumping ftrace buffer: [ 60.695955] (ftrace buffer empty) [ 60.699645] Modules linked in: [ 60.702938] CPU: 1 PID: 4244 Comm: syz-executor0 Not tainted 4.4.151-ge917467 #84 [ 60.710603] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.720027] task: ffff8800b984e000 task.stack: ffff8800b97f0000 [ 60.726061] RIP: 0010:[] [] l2tp_session_create+0x948/0x1030 [ 60.735172] RSP: 0018:ffff8800b97f7b48 EFLAGS: 00010246 [ 60.740597] RAX: 0000000000000000 RBX: ffff8801da2a2280 RCX: 0000000000000006 [ 60.747845] RDX: 1ffff1003b454480 RSI: ffffffff835a4543 RDI: ffff8801da2a2400 [ 60.755089] RBP: ffff8800b97f7bb8 R08: ffff8800b984e900 R09: 0000000000000000 [ 60.762331] R10: 0000000000000000 R11: ffffffff8463a140 R12: ffff8800ba5ae328 [ 60.769579] R13: ffff8800b97f7cd0 R14: ffff8800ba5ae280 R15: ffffffff835a3170 [ 60.776825] FS: 00007f906d54f700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 60.785027] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 60.790986] CR2: 0000000000000080 CR3: 00000000acb2e000 CR4: 00000000001606f0 [ 60.798240] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 60.805487] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 60.812734] Stack: [ 60.814857] ffffffff81140a6a ffff8801da2a22a0 ffff8800ba5ae3d8 ffff8800ba5ae290 [ 60.822860] ffffffff838cba90 ffff8800ba5ae330 ffff8800ba5ae3d0 ffff8801da2a2360 [ 60.830928] ffffffff00000000 ffff8800b9150000 0000000000000000 ffff8800b9150030 [ 60.839114] Call Trace: [ 60.841783] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 60.848083] [] ? _raw_read_unlock_bh+0x30/0x40 [ 60.854302] [] pppol2tp_connect+0x10f0/0x1910 [ 60.860423] [] ? pppol2tp_recv+0x320/0x320 [ 60.866292] [] ? security_socket_connect+0x8f/0xc0 [ 60.872918] [] SYSC_connect+0x1b8/0x300 [ 60.878526] [] ? SYSC_perf_event_open+0x211/0x2470 [ 60.885080] [] ? SYSC_bind+0x280/0x280 [ 60.890590] [] ? get_unused_fd_flags+0xd0/0xd0 [ 60.896796] [] ? do_futex+0x17f0/0x17f0 [ 60.902504] [] ? move_addr_to_kernel+0x50/0x50 [ 60.908821] [] SyS_connect+0x24/0x30 [ 60.914255] [] entry_SYSCALL_64_fastpath+0x22/0x9e [ 60.920820] 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 [ 60.948002] RIP [] l2tp_session_create+0x948/0x1030 [ 60.954785] RSP [ 60.958390] CR2: 0000000000000080 [ 60.967966] ---[ end trace 3741ad7d47e9b6ee ]--- [ 60.972731] Kernel panic - not syncing: Fatal exception [ 60.978416] Dumping ftrace buffer: [ 60.981937] (ftrace buffer empty) [ 60.985621] Kernel Offset: disabled [ 60.989223] Rebooting in 86400 seconds..