[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 21.771653] 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: [ 26.977921] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 27.656004] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 28.360320] random: sshd: uninitialized urandom read (32 bytes read, 70 bits of entropy available) [ 48.598172] random: sshd: uninitialized urandom read (32 bytes read, 83 bits of entropy available) Warning: Permanently added '10.128.0.46' (ECDSA) to the list of known hosts. [ 54.301589] random: sshd: uninitialized urandom read (32 bytes read, 87 bits of entropy available) [ 54.401562] IPVS: Creating netns size=2552 id=1 RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported Error: argument "bridge0" is wrong: Device does not exist Error: argument "bridge0" is wrong: Device does not exist [ 54.575207] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 54.590792] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready Error: argument "bond0" is wrong: Device does not exist Error: argument "bond0" is wrong: Device does not exist [ 54.670745] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 54.685275] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready Error: argument "team0" is wrong: Device does not exist Error: argument "team0" is wrong: Device does not exist [ 54.766574] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 54.781726] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 54.798068] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 54.814654] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready RTNETLINK answers: Operation not supported Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" [ 54.890610] ip (3943) used greatest stack depth: 23600 bytes left Cannot find device "vcan0" Cannot find device "vcan0" Cannot find device "vcan0" Cannot find device "vcan0" RTNETLINK answers: Operation not supported Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "team0" Cannot find device "team0" [ 55.531733] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 55.568419] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready Cannot find device "team0" Cannot find device "team0" executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 59.159245] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [ 59.167483] IP: [] l2tp_session_free+0x11c/0x200 [ 59.174036] PGD 1cbffe067 PUD 1da21c067 PMD 0 [ 59.178983] Oops: 0002 [#1] PREEMPT SMP KASAN [ 59.184003] Dumping ftrace buffer: [ 59.187520] (ftrace buffer empty) [ 59.191207] Modules linked in: [ 59.194611] CPU: 1 PID: 3856 Comm: syz-executor014 Not tainted 4.4.147-ga5fc665 #16 [ 59.202375] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 59.211708] task: ffff8800bb8bc800 task.stack: ffff8801c7f10000 [ 59.217739] RIP: 0010:[] [] l2tp_session_free+0x11c/0x200 [ 59.226582] RSP: 0018:ffff8801db307af0 EFLAGS: 00010246 [ 59.232008] RAX: dffffc0000000000 RBX: ffff8801d0da6500 RCX: 0000000000000000 [ 59.239261] RDX: 1ffff1003a34ec80 RSI: ffffffff835a3531 RDI: ffff8801d1a76400 [ 59.246520] RBP: ffff8801db307b10 R08: ffff8800bb8bd100 R09: 0000000000000000 [ 59.253887] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d1a76280 [ 59.261134] R13: ffff8801d0da6508 R14: 0000000000000000 R15: 0000000000000000 [ 59.268376] FS: 0000000000000000(0000) GS:ffff8801db300000(0063) knlGS:00000000093b2840 [ 59.276673] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 59.282525] CR2: 0000000000000080 CR3: 00000001cbfff000 CR4: 00000000001606f0 [ 59.289763] Stack: [ 59.291878] ffff8800ba917700 ffff8801d0da6500 ffff8800ba917ad0 ffffffff8348b71e [ 59.299979] ffff8801db307b38 ffffffff835acfd7 ffff8800ba917700 ffffffff835acf00 [ 59.307962] ffff8800b3b93ba0 ffff8801db307b60 ffffffff82f34a2c ffff8800ba917700 [ 59.316041] Call Trace: [ 59.318597] [ 59.320638] [] ? ndisc_error_report+0xbe/0x1a0 [ 59.327136] [] pppol2tp_session_destruct+0xd7/0x110 [ 59.333822] [] ? pppol2tp_seq_start+0x4e0/0x4e0 [ 59.340127] [] sk_destruct+0x4c/0x4c0 [ 59.345547] [] __sk_free+0x4f/0x220 [ 59.353135] [] sock_wfree+0x103/0x140 [ 59.359060] [] ? sk_receive_skb+0x950/0x950 [ 59.365004] [] skb_release_head_state+0x103/0x210 [ 59.371489] [] skb_release_all+0x15/0x60 [ 59.377168] [] __kfree_skb+0x15/0x20 [ 59.382501] [] kfree_skb+0xf7/0x3e0 [ 59.387752] [] ? ip6_redirect_no_header+0x3a0/0x3a0 [ 59.394681] [] ndisc_error_report+0xbe/0x1a0 [ 59.400799] [] neigh_invalidate+0x234/0x530 [ 59.406750] [] neigh_timer_handler+0x838/0xa50 [ 59.412964] [] call_timer_fn+0x18c/0x870 [ 59.418660] [] ? call_timer_fn+0xda/0x870 [ 59.424450] [] ? debug_object_deactivate+0x214/0x340 [ 59.431181] [] ? __neigh_for_each_release+0x3a0/0x3a0 [ 59.438015] [] ? process_timeout+0x20/0x20 [ 59.443874] [] ? _raw_spin_unlock_irq+0x27/0x50 [ 59.450168] [] ? trace_hardirqs_on_caller+0x266/0x590 [ 59.456989] [] run_timer_softirq+0x642/0xb90 [ 59.463031] [] ? __neigh_for_each_release+0x3a0/0x3a0 [ 59.469858] [] ? call_timer_fn+0x870/0x870 [ 59.475727] [] __do_softirq+0x22c/0xa1a [ 59.481440] [] irq_exit+0x10d/0x140 [ 59.486757] [] smp_apic_timer_interrupt+0x81/0xa0 [ 59.493242] [] apic_timer_interrupt+0xa0/0xb0 [ 59.499368] [ 59.501408] [] ? _raw_spin_unlock_irqrestore+0x5f/0x70 [ 59.508603] [] add_wait_queue+0x76/0xa0 [ 59.514213] [] do_wait+0x1b5/0xa30 [ 59.519377] [] ? wait_consider_task+0x35f0/0x35f0 [ 59.525861] [] ? free_object+0x1e/0x2a0 [ 59.531462] [] ? _raw_spin_unlock_irqrestore+0x5a/0x70 [ 59.538361] [] SyS_wait4+0x12b/0x1f0 [ 59.543694] [] ? SyS_waitid+0x2d0/0x2d0 [ 59.549297] [] ? kill_orphaned_pgrp+0x390/0x390 [ 59.555607] [] C_SYSC_wait4+0x237/0x280 [ 59.561230] [] ? ktime_get_ts64+0x251/0x310 [ 59.567238] [] ? posix_ktime_get_ts+0x15/0x20 [ 59.573405] [] ? put_compat_rusage+0x5c0/0x5c0 [ 59.579631] [] ? __might_fault+0x92/0x1d0 [ 59.585552] [] ? SyS_clock_gettime+0x11e/0x1e0 [ 59.591758] [] ? SyS_clock_settime+0x210/0x210 [ 59.597963] [] ? __compat_put_timespec.isra.12+0xd3/0x150 [ 59.605132] [] ? compat_put_timespec+0xc2/0xe0 [ 59.611344] [] ? compat_SyS_clock_gettime+0x115/0x1a0 [ 59.618155] [] compat_SyS_wait4+0x2c/0x40 [ 59.623948] [] sys32_waitpid+0x25/0x30 [ 59.629459] [] ? sys32_mmap+0x110/0x110 [ 59.635409] [] do_fast_syscall_32+0x324/0x8b0 [ 59.641534] [] sysenter_flags_fixed+0xd/0x1a [ 59.647562] 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 55 02 db fd e8 50 02 db fd 4c [ 59.674657] RIP [] l2tp_session_free+0x11c/0x200 [ 59.681283] RSP [ 59.684884] CR2: 0000000000000080 [ 59.688347] ---[ end trace b0dc6d5fc9a1ebcb ]--- [ 59.693090] Kernel panic - not syncing: Fatal exception in interrupt [ 59.699820] Dumping ftrace buffer: [ 59.703340] (ftrace buffer empty) [ 59.707024] Kernel Offset: disabled [ 59.710627] Rebooting in 86400 seconds..