[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 13.190078] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 14.525641] random: sshd: uninitialized urandom read (32 bytes read) [ 14.768101] random: sshd: uninitialized urandom read (32 bytes read) [ 15.259196] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.30' (ECDSA) to the list of known hosts. [ 20.979549] urandom_read: 1 callbacks suppressed [ 20.979552] random: sshd: uninitialized urandom read (32 bytes read) 2018/08/22 05:34:39 parsed 1 programs [ 22.431088] random: cc1: uninitialized urandom read (8 bytes read) 2018/08/22 05:34:41 executed programs: 0 [ 23.756563] IPVS: Creating netns size=2536 id=1 [ 23.878241] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 23.889354] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 23.935199] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 23.946088] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready [ 23.989516] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 24.001088] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 24.012737] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 24.032786] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 24.522498] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 24.546627] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 24.553307] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 24.560769] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 24.763048] hrtimer: interrupt took 29610 ns [ 24.789824] l2tp_core: tunl 4: sockfd_lookup(fd=6) returned -9 [ 25.116075] l2tp_core: tunl 4: sockfd_lookup(fd=6) returned -9 [ 25.334940] l2tp_core: tunl 4: sockfd_lookup(fd=6) returned -9 [ 25.553207] l2tp_core: tunl 4: sockfd_lookup(fd=6) returned -9 [ 25.682841] l2tp_core: tunl 4: sockfd_lookup(fd=6) returned -9 [ 26.104805] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [ 26.113041] IP: [] l2tp_session_create+0xc60/0x16f0 [ 26.119722] PGD 1cd508067 [ 26.122363] PUD 1cd892067 PMD 0 [ 26.125872] [ 26.127505] Oops: 0002 [#1] PREEMPT SMP KASAN [ 26.131972] Dumping ftrace buffer: [ 26.135482] (ftrace buffer empty) [ 26.139161] Modules linked in: [ 26.142460] CPU: 0 PID: 4728 Comm: syz-executor0 Not tainted 4.9.122-g54068d6 #26 [ 26.150047] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.159376] task: ffff8801cd741800 task.stack: ffff8801b55c0000 [ 26.165428] RIP: 0010:[] [] l2tp_session_create+0xc60/0x16f0 [ 26.174532] RSP: 0018:ffff8801b55c7ac0 EFLAGS: 00010246 [ 26.179952] RAX: 0000000000000000 RBX: ffff8801cd816780 RCX: 1ffff10039ae841d [ 26.187230] RDX: 1ffff10039b02c80 RSI: ffff8801cd7420c8 RDI: ffff8801cd816400 [ 26.194471] RBP: ffff8801b55c7b60 R08: ffff8801cd7420e8 R09: 0000000000000000 [ 26.201711] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801cd8162d8 [ 26.208952] R13: 0000000000000000 R14: ffff8801cd816280 R15: ffff8801b55c7c78 [ 26.216195] FS: 00007fd09b4c9700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 26.224390] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 26.230259] CR2: 0000000000000080 CR3: 00000001cdfbb000 CR4: 00000000001606f0 [ 26.237503] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 26.244747] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 26.251994] Stack: [ 26.254118] 0000000000000201 ffffffff836c9151 ffff8801b55c7ae0 ffffffff81237ecd [ 26.262133] ffff8801cd816280 ffff8801cd8168d8 ffff8801cd8162d8 ffff8801cd8168d0 [ 26.270111] ffff8801cd816830 ffff8801cd8162a0 0000000000000000 0000000000000000 [ 26.278086] Call Trace: [ 26.280646] [] ? l2tp_session_get+0x1d1/0x790 [ 26.286769] [] ? trace_hardirqs_on+0xd/0x10 [ 26.292711] [] pppol2tp_connect+0x10d7/0x18f0 [ 26.298825] [] ? pppol2tp_seq_show+0xc30/0xc30 [ 26.305059] [] ? security_socket_connect+0x8f/0xc0 [ 26.311631] [] SYSC_connect+0x1b8/0x300 [ 26.317227] [] ? SYSC_bind+0x280/0x280 [ 26.322737] [] ? do_futex+0x17c0/0x17c0 [ 26.328336] [] ? move_addr_to_kernel+0x50/0x50 [ 26.334539] [] SyS_connect+0x24/0x30 [ 26.339877] [] ? SyS_accept+0x30/0x30 [ 26.345299] [] do_syscall_64+0x1a6/0x490 [ 26.351031] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 26.357943] Code: 00 00 49 8d be 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 7b 09 00 00 49 8b 86 80 01 00 00 ff 80 80 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 55 d0 [ 26.384749] RIP [] l2tp_session_create+0xc60/0x16f0 [ 26.391529] RSP [ 26.395137] CR2: 0000000000000080 [ 26.399494] ---[ end trace 83b028af66f4853a ]--- [ 26.404241] Kernel panic - not syncing: Fatal exception [ 26.409932] Dumping ftrace buffer: [ 26.413448] (ftrace buffer empty) [ 26.417129] Kernel Offset: disabled [ 26.420744] Rebooting in 86400 seconds..