[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.561521] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.155156] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 23.457439] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 24.586285] random: sshd: uninitialized urandom read (32 bytes read, 126 bits of entropy available) [ 24.696448] random: nonblocking pool is initialized Warning: Permanently added '10.128.10.25' (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 [ 30.292317] page:ffffea0007340000 count:2 mapcount:0 mapping: (null) index:0x0 [ 30.309652] flags: 0x8000000000004004(referenced|head) [ 30.315620] page dumped because: VM_BUG_ON_PAGE(!PageLocked(page)) [ 30.321921] ------------[ cut here ]------------ [ 30.326654] kernel BUG at mm/filemap.c:819! [ 30.330951] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 30.336773] Dumping ftrace buffer: [ 30.340290] (ftrace buffer empty) [ 30.343976] Modules linked in: [ 30.347265] CPU: 1 PID: 3674 Comm: syz-executor163 Not tainted 4.4.131-g3702e76 #37 [ 30.355037] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.364367] task: ffff8801cfec8000 task.stack: ffff8801ce428000 [ 30.370404] RIP: 0010:[] [] unlock_page+0x115/0x150 [ 30.378733] RSP: 0018:ffff8801ce42f760 EFLAGS: 00010293 [ 30.384155] RAX: ffffffff83a6e7c0 RBX: ffffea0007340000 RCX: 0000000000000000 [ 30.391399] RDX: 0000000000000000 RSI: ffffffff81513249 RDI: ffff8801cfec88dc [ 30.398641] RBP: ffff8801ce42f780 R08: 0000000000000001 R09: 0000000000000000 [ 30.405885] R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 [ 30.413129] R13: ffff8801ce42fa30 R14: ffffea0007341480 R15: ffffea0007340008 [ 30.420380] FS: 0000000000000000(0000) GS:ffff8801db300000(0063) knlGS:00000000f77e5b40 [ 30.428994] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 30.434851] CR2: 00000000204a4ff0 CR3: 00000001cfe93000 CR4: 00000000001606f0 [ 30.442099] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.449342] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.456596] Stack: [ 30.458718] ffffea0007340000 dffffc0000000000 ffff8801ce42fa30 ffffea0007341480 [ 30.466706] ffff8801ce42f868 ffffffff812cc1bc 0000000000000001 ffff8801ce42f818 [ 30.475045] 0000000000000046 ffff8801cf69b700 00000000cfec88d8 ffff8801ce42fa40 [ 30.483032] Call Trace: [ 30.485600] [] get_futex_key+0xadc/0xd80 [ 30.491283] [] ? futex_lock_pi_atomic+0x2b0/0x2b0 [ 30.497751] [] ? _raw_spin_unlock_irqrestore+0x45/0x70 [ 30.504663] [] futex_wait_setup+0xd9/0x330 [ 30.510520] [] ? futex_wake+0x460/0x460 [ 30.516116] [] ? __hrtimer_init+0x143/0x1e0 [ 30.522062] [] futex_wait+0x2af/0x600 [ 30.527485] [] ? futex_wait_setup+0x330/0x330 [ 30.533614] [] ? native_set_pte_at+0xe0/0xe0 [ 30.539648] [] ? do_huge_pmd_anonymous_page+0x52d/0x9d0 [ 30.546635] [] ? clock_was_set_work+0x30/0x30 [ 30.552766] [] do_futex+0x2a2/0x1770 [ 30.558106] [] ? exit_robust_list+0x220/0x220 [ 30.564225] [] ? retint_kernel+0x2d/0x2d [ 30.569911] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 30.576723] [] ? ktime_add_safe+0xea/0x150 [ 30.582579] [] ? SyS_alarm+0x20/0x20 [ 30.587916] [] ? kvm_clock_read+0x23/0x40 [ 30.593686] [] ? kvm_clock_get_cycles+0x9/0x10 [ 30.599891] [] ? compat_SyS_futex+0x26d/0x2f0 [ 30.606009] [] compat_SyS_futex+0x1d9/0x2f0 [ 30.611957] [] ? compat_SyS_get_robust_list+0x310/0x310 [ 30.618944] [] ? __bad_area_nosemaphore+0x21e/0x310 [ 30.625582] [] ? do_fast_syscall_32+0xdb/0x8b0 [ 30.631788] [] ? compat_SyS_get_robust_list+0x310/0x310 [ 30.638776] [] do_fast_syscall_32+0x326/0x8b0 [ 30.644897] [] sysenter_flags_fixed+0xd/0x17 [ 30.650923] 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 [ 30.677832] RIP [] unlock_page+0x115/0x150 [ 30.683811] RSP [ 30.688037] ---[ end trace 8a8303cc76faada5 ]--- executing program [ 30.692872] Kernel panic - not syncing: Fatal exception [ 30.698703] Dumping ftrace buffer: [ 30.702218] (ftrace buffer empty) [ 30.705900] Kernel Offset: disabled [ 30.709496] Rebooting in 86400 seconds..