[....] 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[   20.233028] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available)
[?25l[?1c7[ ok 8[?25h[?0c.
[   20.746755] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available)
[   21.127045] random: sshd: uninitialized urandom read (32 bytes read, 34 bits of entropy available)

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   22.152938] random: nonblocking pool is initialized
Warning: Permanently added '10.128.0.40' (ECDSA) to the list of known hosts.
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[   31.860108] page:ffffea0007278000 count:2 mapcount:0 mapping:          (null) index:0x0
[   31.873291] flags: 0x8000000000004004(referenced|head)
[   31.879139] page dumped because: VM_BUG_ON_PAGE(!PageLocked(page))
[   31.885941] ------------[ cut here ]------------
[   31.890684] kernel BUG at mm/filemap.c:819!
[   31.894981] invalid opcode: 0000 [#1] PREEMPT SMP KASAN
[   31.900780] Dumping ftrace buffer:
[   31.904315]    (ftrace buffer empty)
[   31.908001] Modules linked in:
[   31.911284] CPU: 0 PID: 3789 Comm: syz-executor703 Not tainted 4.4.131-g6ec0e3f #35
[   31.919049] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   31.928376] task: ffff8801cae8c800 task.stack: ffff8801d9658000
[   31.934404] RIP: 0010:[<ffffffff8141de15>]  [<ffffffff8141de15>] unlock_page+0x115/0x150
[   31.942733] RSP: 0018:ffff8801d965f7d8  EFLAGS: 00010293
[   31.948156] RAX: ffffffff83a6e7c0 RBX: ffffea0007278000 RCX: 0000000000000000
[   31.955402] RDX: 0000000000000000 RSI: ffffffff81513249 RDI: ffff8801cae8d0dc
[   31.962645] RBP: ffff8801d965f7f8 R08: 0000000000000001 R09: 0000000000000000
[   31.969889] R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
[   31.977130] R13: ffff8801d965faa8 R14: ffffea0007279480 R15: ffffea0007278008
[   31.984373] FS:  00007f43a3dfa700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
[   31.992570] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   31.998424] CR2: 00000000204a4ff0 CR3: 00000001d02c9000 CR4: 00000000001606f0
[   32.005669] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   32.012911] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   32.020151] Stack:
[   32.022272]  ffffea0007278000 dffffc0000000000 ffff8801d965faa8 ffffea0007279480
[   32.030265]  ffff8801d965f8e0 ffffffff812cc1bc 0000000000000001 ffff8801d965f890
[   32.038253]  0000000000000046 ffff8801caff9400 00000000cae8d0d8 ffff8801d965fab8
[   32.046239] Call Trace:
[   32.048803]  [<ffffffff812cc1bc>] get_futex_key+0xadc/0xd80
[   32.054487]  [<ffffffff812cb6e0>] ? futex_lock_pi_atomic+0x2b0/0x2b0
[   32.060958]  [<ffffffff838bf2a5>] ? _raw_spin_unlock_irqrestore+0x45/0x70
[   32.067859]  [<ffffffff812cc999>] futex_wait_setup+0xd9/0x330
[   32.073715]  [<ffffffff812cc8c0>] ? futex_wake+0x460/0x460
[   32.079313]  [<ffffffff8129d143>] ? __hrtimer_init+0x143/0x1e0
[   32.085260]  [<ffffffff812cce9f>] futex_wait+0x2af/0x600
[   32.090687]  [<ffffffff812ccbf0>] ? futex_wait_setup+0x330/0x330
[   32.096805]  [<ffffffff8129b4a0>] ? clock_was_set_work+0x30/0x30
[   32.102921]  [<ffffffff812d07b2>] do_futex+0x2a2/0x1770
[   32.108258]  [<ffffffff812d0510>] ? exit_robust_list+0x220/0x220
[   32.114379]  [<ffffffff810d7ac5>] ? __do_page_fault+0x385/0xa10
[   32.120413]  [<ffffffff8122e69b>] ? trace_hardirqs_on_caller+0x38b/0x590
[   32.127225]  [<ffffffff8129a70a>] ? ktime_add_safe+0xea/0x150
[   32.133081]  [<ffffffff8129a620>] ? SyS_alarm+0x20/0x20
[   32.138415]  [<ffffffff810cbeb3>] ? kvm_clock_read+0x23/0x40
[   32.144187]  [<ffffffff810cbed9>] ? kvm_clock_get_cycles+0x9/0x10
[   32.150390]  [<ffffffff812d1f04>] ? SyS_futex+0x284/0x300
[   32.155900]  [<ffffffff812d1e70>] SyS_futex+0x1f0/0x300
[   32.161236]  [<ffffffff812d1c80>] ? do_futex+0x1770/0x1770
[   32.166833]  [<ffffffff838c08d8>] ? retint_user+0x18/0x3c
[   32.172342]  [<ffffffff81003017>] ? trace_hardirqs_on_thunk+0x17/0x19
[   32.178894]  [<ffffffff838bfd25>] entry_SYSCALL_64_fastpath+0x22/0x9e
executing program
[   32.185439] Code: e8 48 8d 04 c0 49 8d 3c c6 e8 48 c0 df ff 5b 41 5c 41 5d 41 5e 5d c3 e8 da 33 f3 ff 48 c7 c6 60 aa a9 83 48 89 df e8 4b eb 06 00 <0f> 0b 48 89 df e8 f1 b1 0d 00 e9 0a ff ff ff e8 e7 b1 0d 00 e9 
[   32.212228] RIP  [<ffffffff8141de15>] unlock_page+0x115/0x150
[   32.218207]  RSP <ffff8801d965f7d8>
[   32.222678] ---[ end trace 11b32a9955d7bd2b ]---
[   32.227863] Kernel panic - not syncing: Fatal exception
[   32.233642] Dumping ftrace buffer:
[   32.237155]    (ftrace buffer empty)
[   32.240836] Kernel Offset: disabled
[   32.244434] Rebooting in 86400 seconds..