[....] 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[ 22.013048] random: sshd: uninitialized urandom read (32 bytes read, 35 bits of entropy available) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 26.141199] random: sshd: uninitialized urandom read (32 bytes read, 40 bits of entropy available) [ 26.569938] random: sshd: uninitialized urandom read (32 bytes read, 41 bits of entropy available) [ 27.591593] random: nonblocking pool is initialized Warning: Permanently added '10.128.10.38' (ECDSA) to the list of known hosts. 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 [ 33.403567] page:ffffea0007198000 count:2 mapcount:0 mapping: (null) index:0x0 [ 33.416624] flags: 0x8000000000004004(referenced|head) [ 33.422446] page dumped because: VM_BUG_ON_PAGE(!PageLocked(page)) [ 33.428890] ------------[ cut here ]------------ [ 33.433632] kernel BUG at mm/filemap.c:819! [ 33.437927] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 33.443756] Dumping ftrace buffer: [ 33.447272] (ftrace buffer empty) [ 33.451073] Modules linked in: [ 33.454357] CPU: 0 PID: 3857 Comm: syz-executor894 Not tainted 4.4.131-g4fca5a0 #33 [ 33.462122] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.471453] task: ffff8800abf1c800 task.stack: ffff8800abe68000 [ 33.477485] RIP: 0010:[] [] unlock_page+0x115/0x150 [ 33.485818] RSP: 0018:ffff8800abe6f7d8 EFLAGS: 00010293 [ 33.491241] RAX: ffffffff83a6e7c0 RBX: ffffea0007198000 RCX: 0000000000000000 [ 33.498484] RDX: 0000000000000000 RSI: ffffffff81513389 RDI: ffff8800abf1d0dc [ 33.505734] RBP: ffff8800abe6f7f8 R08: 0000000000000001 R09: 0000000000000000 [ 33.512976] R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 [ 33.520230] R13: ffff8800abe6faa8 R14: ffffea0007199480 R15: ffffea0007198008 [ 33.527476] FS: 00007feb3e954700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 33.535676] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 33.541530] CR2: 0000000020196000 CR3: 00000000b389b000 CR4: 00000000001606f0 [ 33.548785] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 33.556031] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 33.563275] Stack: [ 33.565398] ffffea0007198000 dffffc0000000000 ffff8800abe6faa8 ffffea0007199480 [ 33.573399] ffff8800abe6f8e0 ffffffff812cc1bc 0000000000000001 ffff8800abe6f890 [ 33.581677] 0000000000000046 ffff8800bbbd1900 00000000abf1d0d8 ffff8800abe6fab8 [ 33.589768] Call Trace: [ 33.592335] [] get_futex_key+0xadc/0xd80 [ 33.598020] [] ? futex_lock_pi_atomic+0x2b0/0x2b0 [ 33.604505] [] ? _raw_spin_unlock_irqrestore+0x45/0x70 [ 33.611406] [] futex_wait_setup+0xd9/0x330 [ 33.617264] [] ? futex_wake+0x460/0x460 [ 33.622862] [] ? __hrtimer_init+0x143/0x1e0 [ 33.628815] [] futex_wait+0x2af/0x600 [ 33.634239] [] ? futex_wait_setup+0x330/0x330 [ 33.640357] [] ? clock_was_set_work+0x30/0x30 [ 33.646479] [] do_futex+0x2a2/0x1770 [ 33.651835] [] ? exit_robust_list+0x220/0x220 [ 33.657957] [] ? __do_page_fault+0x385/0xa10 [ 33.663994] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 33.670805] [] ? ktime_add_safe+0xea/0x150 [ 33.676663] [] ? SyS_alarm+0x20/0x20 [ 33.682016] [] ? kvm_clock_read+0x23/0x40 [ 33.687789] [] ? kvm_clock_get_cycles+0x9/0x10 [ 33.693998] [] ? SyS_futex+0x284/0x300 [ 33.699511] [] SyS_futex+0x1f0/0x300 [ 33.704849] [] ? do_futex+0x1770/0x1770 [ 33.710446] [] ? retint_user+0x18/0x3c [ 33.715958] [] ? trace_hardirqs_on_thunk+0x17/0x19 [ 33.722511] [] entry_SYSCALL_64_fastpath+0x22/0x9e executing program [ 33.729060] Code: e8 48 8d 04 c0 49 8d 3c c6 e8 08 bf df ff 5b 41 5c 41 5d 41 5e 5d c3 e8 9a 32 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 [ 33.756096] RIP [] unlock_page+0x115/0x150 [ 33.762075] RSP [ 33.766491] ---[ end trace 9b294467f9241f00 ]--- [ 33.771256] Kernel panic - not syncing: Fatal exception [ 33.777147] Dumping ftrace buffer: [ 33.780662] (ftrace buffer empty) [ 33.784346] Kernel Offset: disabled [ 33.787944] Rebooting in 86400 seconds..