[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.699429] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 29.537673] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 29.866965] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 30.567835] random: sshd: uninitialized urandom read (32 bytes read, 70 bits of entropy available) [ 30.736372] random: sshd: uninitialized urandom read (32 bytes read, 72 bits of entropy available) Warning: Permanently added '10.128.0.8' (ECDSA) to the list of known hosts. [ 36.346527] random: sshd: uninitialized urandom read (32 bytes read, 77 bits of entropy available) 2018/08/22 20:43:00 parsed 1 programs [ 37.937753] random: cc1: uninitialized urandom read (8 bytes read, 79 bits of entropy available) 2018/08/22 20:43:03 executed programs: 0 [ 39.144207] IPVS: Creating netns size=2552 id=1 [ 39.389616] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 39.404168] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 39.487992] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 39.503569] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready [ 39.586071] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 39.600945] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 39.619030] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 39.636294] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 40.401233] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 40.440611] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 40.747672] hrtimer: interrupt took 24768 ns [ 40.785109] l2tp_core: tunl 4: sockfd_lookup(fd=7) returned -9 [ 40.834468] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [ 40.842699] IP: [<ffffffff835aa438>] l2tp_session_create+0x948/0x1030 [ 40.849407] PGD b06e2067 PUD bafa0067 PMD 0 [ 40.854144] Oops: 0002 [#1] PREEMPT SMP KASAN [ 40.859088] Dumping ftrace buffer: [ 40.862600] (ftrace buffer empty) [ 40.866283] Modules linked in: [ 40.869572] CPU: 0 PID: 4112 Comm: syz-executor0 Not tainted 4.4.151-ge917467 #20 [ 40.877167] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.886494] task: ffff8800b0c6e000 task.stack: ffff8800bad30000 [ 40.892526] RIP: 0010:[<ffffffff835aa438>] [<ffffffff835aa438>] l2tp_session_create+0x948/0x1030 [ 40.901643] RSP: 0018:ffff8800bad37ad0 EFLAGS: 00010246 [ 40.907076] RAX: 0000000000000000 RBX: ffff8800ba522280 RCX: 0000000000000006 [ 40.914322] RDX: 1ffff100174a4480 RSI: ffffffff835a4543 RDI: ffff8800ba522400 [ 40.921570] RBP: ffff8800bad37b40 R08: ffff8800b0c6e900 R09: 0000000000000000 [ 40.928820] R10: 0000000000000000 R11: ffffffff8463a140 R12: ffff8800babe60a8 [ 40.936081] R13: ffff8800bad37c58 R14: ffff8800babe6000 R15: ffffffff835a3170 [ 40.943548] FS: 0000000000000000(0000) GS:ffff8801db200000(0063) knlGS:00000000f7773b40 [ 40.943552] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 40.943557] CR2: 0000000000000080 CR3: 00000000bab7f000 CR4: 00000000001606f0 [ 40.943562] Stack: [ 40.943578] ffffffff81140a6a ffff8800ba5222a0 ffff8800babe6158 ffff8800babe6010 [ 40.943585] ffffffff838cba90 ffff8800babe60b0 ffff8800babe6150 ffff8800ba522360 [ 40.943594] ffffffff00000000 ffff8800baa0b300 0000000000000000 ffff8800baa0b330 [ 40.943595] Call Trace: [ 40.943607] [<ffffffff81140a6a>] ? __local_bh_enable_ip+0x6a/0xd0 [ 40.943617] [<ffffffff838cba90>] ? _raw_read_unlock_bh+0x30/0x40 [ 40.943627] [<ffffffff835ae830>] pppol2tp_connect+0x10f0/0x1910 [ 40.943635] [<ffffffff835ad740>] ? pppol2tp_recv+0x320/0x320 [ 40.943647] [<ffffffff81c5700f>] ? security_socket_connect+0x8f/0xc0 [ 40.943665] [<ffffffff82f27758>] SYSC_connect+0x1b8/0x300 [ 40.943672] [<ffffffff8157ffea>] ? __fd_install+0x21a/0x600 [ 40.943680] [<ffffffff82f275a0>] ? SYSC_bind+0x280/0x280 [ 40.943687] [<ffffffff81580025>] ? __fd_install+0x255/0x600 [ 40.943694] [<ffffffff8157fdd0>] ? get_unused_fd_flags+0xd0/0xd0 [ 40.943704] [<ffffffff812d59b0>] ? compat_SyS_get_robust_list+0x310/0x310 [ 40.943712] [<ffffffff838ccd29>] ? retint_kernel+0x2d/0x2d [ 40.943720] [<ffffffff81609320>] ? timerfd_clock_was_set+0x280/0x280 [ 40.943729] [<ffffffff82f2a094>] SyS_connect+0x24/0x30 [ 40.943736] [<ffffffff82f2a070>] ? SyS_accept+0x30/0x30 [ 40.943745] [<ffffffff81006d94>] do_fast_syscall_32+0x324/0x8b0 [ 40.943752] [<ffffffff838cda83>] sysenter_flags_fixed+0xd/0x1a [ 40.943867] 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 <f0> ff 80 80 00 00 00 48 8d 43 20 48 89 c7 48 89 45 b0 e8 f1 13 [ 40.943876] RIP [<ffffffff835aa438>] l2tp_session_create+0x948/0x1030 [ 40.943879] RSP <ffff8800bad37ad0> [ 40.943881] CR2: 0000000000000080 [ 40.947948] ---[ end trace 6eb79002335717e1 ]--- [ 40.947952] Kernel panic - not syncing: Fatal exception [ 40.952066] Dumping ftrace buffer: [ 40.952070] (ftrace buffer empty) [ 40.952072] Kernel Offset: disabled [ 41.147713] Rebooting in 86400 seconds..