[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   18.895416] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   22.955541] random: sshd: uninitialized urandom read (32 bytes read)
[   23.285558] random: sshd: uninitialized urandom read (32 bytes read)
[   24.151913] random: sshd: uninitialized urandom read (32 bytes read)
[   24.301162] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.40' (ECDSA) to the list of known hosts.
[   29.726056] random: sshd: uninitialized urandom read (32 bytes read)
2018/07/15 18:54:37 parsed 1 programs
[   31.235794] random: cc1: uninitialized urandom read (8 bytes read)
2018/07/15 18:54:39 executed programs: 0
[   32.832701] IPVS: ftp: loaded support on port[0] = 21
[   37.519290] ------------[ cut here ]------------
[   37.524296] kernel BUG at fs/userfaultfd.c:883!
[   37.529081] invalid opcode: 0000 [#1] SMP KASAN
[   37.533757] CPU: 0 PID: 4580 Comm: syz-executor0 Not tainted 4.18.0-rc4+ #51
[   37.540938] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   37.550287] RIP: 0010:userfaultfd_release+0x5fb/0x770
[   37.555453] Code: 00 31 c0 48 8b 4d d0 65 48 33 0c 25 28 00 00 00 0f 85 a1 00 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 75 be a0 ff <0f> 0b 4c 89 f7 e8 0b 9e de ff e9 11 fc ff ff 4c 89 e7 e8 5e 9d de 
[   37.574581] RSP: 0018:ffff8801d8b5fa30 EFLAGS: 00010293
[   37.579928] RAX: ffff8801d868a3c0 RBX: dffffc0000000000 RCX: ffffffff81db4a59
[   37.587178] RDX: 0000000000000000 RSI: ffffffff81db4ccb RDI: 0000000000000000
[   37.594428] RBP: ffff8801d8b5fb80 R08: ffff8801d868a3c0 R09: 0000000000000000
[   37.601691] R10: ffff8801d868abf8 R11: 16fb0df9f74494d6 R12: ffff8801d8458840
[   37.608948] R13: 0000000000000000 R14: ffff8801d8458738 R15: 0000000000000000
[   37.616209] FS:  0000000000000000(0000) GS:ffff8801dae00000(0063) knlGS:00000000095c4900
[   37.624423] CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
[   37.630287] CR2: 0000000008140000 CR3: 00000001d4ba8000 CR4: 00000000001406f0
[   37.637543] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   37.644797] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   37.652066] Call Trace:
[   37.654651]  ? userfaultfd_event_wait_completion+0xc10/0xc10
[   37.660438]  ? fsnotify_first_mark+0x350/0x350
[   37.665009]  ? __fsnotify_parent+0xcc/0x420
[   37.669312]  ? fsnotify+0x14e0/0x14e0
[   37.673104]  ? userfaultfd_event_wait_completion+0xc10/0xc10
[   37.678905]  __fput+0x355/0x8b0
[   37.682172]  ? fput+0x1a0/0x1a0
[   37.685441]  ? _raw_spin_unlock_irq+0x27/0x70
[   37.689920]  ____fput+0x15/0x20
[   37.693183]  task_work_run+0x1ec/0x2a0
[   37.697056]  ? task_work_cancel+0x250/0x250
[   37.701367]  ? exit_to_usermode_loop+0x8c/0x370
[   37.706026]  exit_to_usermode_loop+0x313/0x370
[   37.710599]  ? syscall_slow_exit_work+0x500/0x500
[   37.715440]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   37.720973]  do_fast_syscall_32+0xcd5/0xfb2
[   37.725283]  ? do_int80_syscall_32+0x890/0x890
[   37.729854]  ? do_syscall_64+0x820/0x820
[   37.733899]  ? syscall_return_slowpath+0x31d/0x5e0
[   37.738828]  ? sysret32_from_system_call+0x5/0x46
[   37.743661]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   37.748494]  entry_SYSENTER_compat+0x70/0x7f
[   37.752889] RIP: 0023:0xf7f49cb9
[   37.756230] Code: 55 08 8b 88 64 cd ff ff 8b 98 68 cd ff ff 89 c8 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 1c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 
[   37.775364] RSP: 002b:00000000ff9f0a0c EFLAGS: 00000296 ORIG_RAX: 0000000000000006
[   37.783063] RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000000000
[   37.790315] RDX: 0000000000000006 RSI: 00000000ff9f0a5c RDI: 00000000ff9f16ec
[   37.797574] RBP: 00000000ff9f10c8 R08: 0000000000000000 R09: 0000000000000000
[   37.804844] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[   37.812098] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   37.819357] Modules linked in:
[   37.822541] Dumping ftrace buffer:
[   37.826072]    (ftrace buffer empty)
[   37.829887] ---[ end trace 0f09d4a4b896e98c ]---
[   37.834871] RIP: 0010:userfaultfd_release+0x5fb/0x770
[   37.840081] Code: 00 31 c0 48 8b 4d d0 65 48 33 0c 25 28 00 00 00 0f 85 a1 00 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 75 be a0 ff <0f> 0b 4c 89 f7 e8 0b 9e de ff e9 11 fc ff ff 4c 89 e7 e8 5e 9d de 
[   37.859265] RSP: 0018:ffff8801d8b5fa30 EFLAGS: 00010293
[   37.864756] RAX: ffff8801d868a3c0 RBX: dffffc0000000000 RCX: ffffffff81db4a59
[   37.872336] RDX: 0000000000000000 RSI: ffffffff81db4ccb RDI: 0000000000000000
[   37.879903] RBP: ffff8801d8b5fb80 R08: ffff8801d868a3c0 R09: 0000000000000000
[   37.887629] R10: ffff8801d868abf8 R11: 16fb0df9f74494d6 R12: ffff8801d8458840
[   37.895241] R13: 0000000000000000 R14: ffff8801d8458738 R15: 0000000000000000
[   37.902544] FS:  0000000000000000(0000) GS:ffff8801dae00000(0063) knlGS:00000000095c4900
[   37.910853] CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
[   37.916758] CR2: 0000000008140000 CR3: 00000001d4ba8000 CR4: 00000000001406f0
[   37.924163] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   37.932158] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   37.939556] Kernel panic - not syncing: Fatal exception
[   37.945370] Dumping ftrace buffer:
[   37.948893]    (ftrace buffer empty)
[   37.952583] Kernel Offset: disabled
[   37.956197] Rebooting in 86400 seconds..