[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.201465] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.076084] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 24.404632] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 25.037362] random: sshd: uninitialized urandom read (32 bytes read, 60 bits of entropy available) [ 50.147227] random: sshd: uninitialized urandom read (32 bytes read, 73 bits of entropy available) Warning: Permanently added '10.128.10.62' (ECDSA) to the list of known hosts. [ 55.646629] random: sshd: uninitialized urandom read (32 bytes read, 75 bits of entropy available) 2018/08/29 10:35:42 parsed 1 programs [ 57.214254] random: cc1: uninitialized urandom read (8 bytes read, 77 bits of entropy available) 2018/08/29 10:35:44 executed programs: 0 [ 58.404955] IPVS: Creating netns size=2552 id=1 [ 58.647059] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 58.662302] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 58.742321] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 58.757083] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready [ 58.839788] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 58.854566] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 58.871237] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 58.887164] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 59.609322] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 59.648501] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 59.943743] hrtimer: interrupt took 25791 ns [ 59.952892] l2tp_core: tunl 4: sockfd_lookup(fd=6) returned -9 [ 60.054981] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [ 60.063237] IP: [] l2tp_session_create+0x948/0x1030 [ 60.069939] PGD bb848067 PUD bb2df067 PMD 0 [ 60.074703] Oops: 0002 [#1] PREEMPT SMP KASAN [ 60.079770] Dumping ftrace buffer: [ 60.083294] (ftrace buffer empty) [ 60.086987] Modules linked in: [ 60.090290] CPU: 1 PID: 4164 Comm: syz-executor0 Not tainted 4.4.153-g5e24b4e #26 [ 60.097889] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.107229] task: ffff8800bbb34800 task.stack: ffff8800b9a58000 [ 60.113279] RIP: 0010:[] [] l2tp_session_create+0x948/0x1030 [ 60.122406] RSP: 0018:ffff8800b9a5fad0 EFLAGS: 00010246 [ 60.127854] RAX: 0000000000000000 RBX: ffff8801d98ed680 RCX: 0000000000000006 [ 60.135107] RDX: 1ffff1003b31db00 RSI: ffffffff835a4c93 RDI: ffff8801d98ed800 [ 60.142371] RBP: ffff8800b9a5fb40 R08: 000000000000000a R09: 000000000000ffff [ 60.149641] R10: ffffed001734f158 R11: ffffffff8463a200 R12: ffff8800b9a78aa8 [ 60.156895] R13: ffff8800b9a5fc58 R14: ffff8800b9a78a00 R15: ffffffff835a38c0 [ 60.164156] FS: 0000000000000000(0000) GS:ffff8801db300000(0063) knlGS:00000000f77dab40 [ 60.172365] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 60.178229] CR2: 0000000000000080 CR3: 00000000bba57000 CR4: 00000000001606f0 [ 60.185485] Stack: [ 60.187614] ffffffff81140aba ffff8801d98ed6a0 ffff8800b9a78b58 ffff8800b9a78a10 [ 60.195679] ffffffff838cc1e0 ffff8800b9a78ab0 ffff8800b9a78b50 ffff8801d98ed760 [ 60.203737] ffffffff00000000 ffff8800ba6a8880 0000000000000000 ffff8800ba6a88b0 [ 60.211773] Call Trace: [ 60.214361] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 60.220669] [] ? _raw_read_unlock_bh+0x30/0x40 [ 60.226883] [] pppol2tp_connect+0x10f0/0x1910 [ 60.233009] [] ? pppol2tp_recv+0x320/0x320 [ 60.238883] [] ? security_socket_connect+0x8f/0xc0 [ 60.245449] [] SYSC_connect+0x1b8/0x300 [ 60.251060] [] ? SYSC_perf_event_open+0x211/0x2470 [ 60.257637] [] ? SYSC_bind+0x280/0x280 [ 60.263173] [] ? get_unused_fd_flags+0xd0/0xd0 [ 60.269413] [] ? compat_SyS_get_robust_list+0x310/0x310 [ 60.276427] [] ? move_addr_to_kernel+0x50/0x50 [ 60.282643] [] SyS_connect+0x24/0x30 [ 60.287996] [] ? SyS_accept+0x30/0x30 [ 60.293433] [] do_fast_syscall_32+0x324/0x8b0 [ 60.299562] [] sysenter_flags_fixed+0xd/0x1a [ 60.305599] 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 [ 60.333134] RIP [] l2tp_session_create+0x948/0x1030 [ 60.339920] RSP [ 60.343525] CR2: 0000000000000080 [ 60.348585] ---[ end trace e31332c4165abda9 ]--- [ 60.353339] Kernel panic - not syncing: Fatal exception [ 60.359007] Dumping ftrace buffer: [ 60.362526] (ftrace buffer empty) [ 60.366261] Kernel Offset: disabled [ 60.369870] Rebooting in 86400 seconds..