[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 21.682406] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 25.636561] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 25.964902] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 27.025095] random: sshd: uninitialized urandom read (32 bytes read, 126 bits of entropy available) [ 27.131142] random: nonblocking pool is initialized Warning: Permanently added '10.128.0.32' (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 [ 53.040802] page:ffffea0002dc0000 count:2 mapcount:0 mapping: (null) index:0x0 [ 53.051560] flags: 0x4000000000004004(referenced|head) [ 53.057694] page dumped because: VM_BUG_ON_PAGE(!PageLocked(page)) [ 53.064042] ------------[ cut here ]------------ [ 53.068782] kernel BUG at mm/filemap.c:819! [ 53.073518] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 53.079331] Dumping ftrace buffer: [ 53.082844] (ftrace buffer empty) [ 53.086532] Modules linked in: [ 53.089822] CPU: 1 PID: 3864 Comm: syz-executor471 Not tainted 4.4.131-g4fca5a0 #32 [ 53.097602] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.106935] task: ffff8800bb056000 task.stack: ffff8801c69a8000 [ 53.112963] RIP: 0010:[] [] unlock_page+0x115/0x150 [ 53.121299] RSP: 0018:ffff8801c69af760 EFLAGS: 00010293 [ 53.126809] RAX: ffffffff83a6e7c0 RBX: ffffea0002dc0000 RCX: 0000000000000000 [ 53.134053] RDX: 0000000000000000 RSI: ffffffff81513389 RDI: ffff8800bb0568dc [ 53.141305] RBP: ffff8801c69af780 R08: 0000000000000001 R09: 0000000000000000 [ 53.148548] R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 [ 53.155793] R13: ffff8801c69afa30 R14: ffffea0002dc1480 R15: ffffea0002dc0008 [ 53.163043] FS: 0000000000000000(0000) GS:ffff8801db300000(0063) knlGS:00000000f7766b40 [ 53.171243] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 53.177107] CR2: 00000000204a4ff0 CR3: 00000001d8e7a000 CR4: 00000000001606f0 [ 53.184367] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 53.191612] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 53.198860] Stack: [ 53.200991] ffffea0002dc0000 dffffc0000000000 ffff8801c69afa30 ffffea0002dc1480 [ 53.208976] ffff8801c69af868 ffffffff812cc1bc 0000000000000001 ffff8801c69af818 [ 53.216957] 0000000000000046 ffff8801cc900500 00000000bb0568d8 ffff8801c69afa40 [ 53.224954] Call Trace: [ 53.227519] [] get_futex_key+0xadc/0xd80 [ 53.233203] [] ? futex_lock_pi_atomic+0x2b0/0x2b0 [ 53.239672] [] ? _raw_spin_unlock_irqrestore+0x45/0x70 [ 53.246590] [] futex_wait_setup+0xd9/0x330 [ 53.252458] [] ? futex_wake+0x460/0x460 [ 53.258056] [] ? __hrtimer_init+0x143/0x1e0 [ 53.263999] [] futex_wait+0x2af/0x600 [ 53.269425] [] ? futex_wait_setup+0x330/0x330 [ 53.275543] [] ? native_set_pte_at+0xe0/0xe0 [ 53.281575] [] ? do_huge_pmd_anonymous_page+0x52d/0x9d0 [ 53.288648] [] ? clock_was_set_work+0x30/0x30 [ 53.294767] [] do_futex+0x2a2/0x1770 [ 53.300106] [] ? exit_robust_list+0x220/0x220 [ 53.306223] [] ? retint_kernel+0x2d/0x2d [ 53.312689] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 53.319502] [] ? ktime_add_safe+0xea/0x150 [ 53.325445] [] ? SyS_alarm+0x20/0x20 [ 53.330782] [] ? kvm_clock_read+0x23/0x40 [ 53.336572] [] ? kvm_clock_get_cycles+0x9/0x10 [ 53.342785] [] ? compat_SyS_futex+0x26d/0x2f0 [ 53.348902] [] compat_SyS_futex+0x1d9/0x2f0 [ 53.354850] [] ? compat_SyS_get_robust_list+0x310/0x310 [ 53.361836] [] ? __bad_area_nosemaphore+0x21e/0x310 [ 53.368491] [] ? do_fast_syscall_32+0xdb/0x8b0 [ 53.374729] [] ? compat_SyS_get_robust_list+0x310/0x310 [ 53.381822] [] do_fast_syscall_32+0x326/0x8b0 [ 53.388949] [] sysenter_flags_fixed+0xd/0x17 [ 53.394995] 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 [ 53.421920] RIP [] unlock_page+0x115/0x150 [ 53.427907] RSP [ 53.431838] ---[ end trace 5a9e6aa6c377f8fd ]--- [ 53.436894] Kernel panic - not syncing: Fatal exception [ 53.442640] Dumping ftrace buffer: [ 53.446154] (ftrace buffer empty) [ 53.449843] Kernel Offset: disabled [ 53.453447] Rebooting in 86400 seconds..