Free memory is -1052kB above reserved
lowmemorykiller: Killing 'syz-executor.1' (25880) (tgid 25880), adj 1000,
   to free 12328kB on behalf of 'syz-executor.1' (2115) because
   cache 11848kB is below limit 16384kB for oom_score_adj 6
   Free memory is 8248kB above reserved
INFO: task init:7660 blocked for more than 140 seconds.
      Not tainted 4.4.174+ #4
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
init            D ffff8800bac97718 29280  7660      1 0x00000000
 ffff8800bac97718 ffff8801003f4740 1d90a04e17cc5d57 ffff8801003f4740
 0000000000000000 ffff8801003f5000 ffff8801db71f180 ffff8801db71f1a8
 ffff8801db71e898 ffff8801d6e74740 ffff8801003f4740 ffffed0017592001
Call Trace:
 [<ffffffff82709b79>] schedule+0x99/0x1d0 kernel/sched/core.c:3355
 [<ffffffff8270a333>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3388
 [<ffffffff8270c492>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8270c492>] mutex_lock_nested+0x3c2/0xb80 kernel/locking/mutex.c:621
 [<ffffffff81c8b2aa>] tty_open+0x56a/0xf50 drivers/tty/tty_io.c:2067
 [<ffffffff814a3ec0>] chrdev_open+0x230/0x630 fs/char_dev.c:388
 [<ffffffff8149154f>] do_dentry_open+0x38f/0xbd0 fs/open.c:749
 [<ffffffff81494d3b>] vfs_open+0x10b/0x210 fs/open.c:862
 [<ffffffff814c5ddf>] do_last fs/namei.c:3269 [inline]
 [<ffffffff814c5ddf>] path_openat+0x136f/0x4470 fs/namei.c:3406
 [<ffffffff814ccab1>] do_filp_open+0x1a1/0x270 fs/namei.c:3440
 [<ffffffff81495668>] do_sys_open+0x2f8/0x600 fs/open.c:1038
 [<ffffffff8149599d>] SYSC_open fs/open.c:1056 [inline]
 [<ffffffff8149599d>] SyS_open+0x2d/0x40 fs/open.c:1051
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
1 lock held by init/7660:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81c8b2aa>] tty_open+0x56a/0xf50 drivers/tty/tty_io.c:2067
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 26202 Comm: syz-executor.5 Not tainted 4.4.174+ #4
task: ffff88017a1b0000 task.stack: ffff8800b8848000
RIP: 0010:[<ffffffff81abb5b1>]  [<ffffffff81abb5b1>] radix_tree_maxindex lib/radix-tree.c:320 [inline]
RIP: 0010:[<ffffffff81abb5b1>]  [<ffffffff81abb5b1>] __radix_tree_create+0x71/0x860 lib/radix-tree.c:398
RSP: 0018:ffff8800b884f5f0  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff8801bff6ac40 RCX: ffff8800b884f6d8
RDX: 1ffffffff0634d5e RSI: ffffffff81abb569 RDI: ffffffff831a6af0
RBP: ffff8800b884f670 R08: 0000000000000001 R09: ffff88017a1b0910
R10: ffffffff83a57d60 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000002 R14: dffffc0000000000 R15: ffff8801bff6ac50
FS:  00007f42e12e3700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fceceaabbe0 CR3: 00000000b2c3a000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000041b58ab3 0040000082c4d560 1ffff10017109ec7 ffff8800b884f6b8
 ffff8800b884f6d8 ffffffff8123a761 ffff8800b884f6e8 ffff8800b884f638
 00000000024200ca ffff8801bff6ac40 0000000000000384 0000000000000384
Call Trace:
 [<ffffffff81abbe51>] radix_tree_insert+0xb1/0x290 lib/radix-tree.c:457
 [<ffffffff813fb22e>] shmem_add_to_page_cache+0x21e/0x2e0 mm/shmem.c:309
 [<ffffffff81402103>] shmem_getpage_gfp+0x793/0x1120 mm/shmem.c:1207
 [<ffffffff81405df2>] shmem_getpage mm/shmem.c:130 [inline]
 [<ffffffff81405df2>] shmem_fault+0x1a2/0x6c0 mm/shmem.c:1353
 [<ffffffff8142e82a>] __do_fault+0x1ca/0x350 mm/memory.c:2822
 [<ffffffff8143b9cc>] do_read_fault mm/memory.c:3012 [inline]
 [<ffffffff8143b9cc>] do_fault mm/memory.c:3177 [inline]
 [<ffffffff8143b9cc>] handle_pte_fault mm/memory.c:3346 [inline]
 [<ffffffff8143b9cc>] __handle_mm_fault mm/memory.c:3474 [inline]
 [<ffffffff8143b9cc>] handle_mm_fault+0x1cfc/0x3140 mm/memory.c:3503
 [<ffffffff8142c3c1>] faultin_page mm/gup.c:326 [inline]
 [<ffffffff8142c3c1>] __get_user_pages+0x381/0xfd0 mm/gup.c:522
 [<ffffffff8142dad8>] populate_vma_page_range+0x198/0x230 mm/gup.c:925
 [<ffffffff8142dd29>] __mm_populate+0x1b9/0x300 mm/gup.c:973
 [<ffffffff81409dde>] mm_populate include/linux/mm.h:1926 [inline]
 [<ffffffff81409dde>] vm_mmap_pgoff+0x19e/0x1c0 mm/util.c:300
 [<ffffffff81447b9d>] SYSC_mmap_pgoff mm/mmap.c:1523 [inline]
 [<ffffffff81447b9d>] SyS_mmap_pgoff+0x14d/0x1b0 mm/mmap.c:1481
 [<ffffffff81016bf6>] SYSC_mmap arch/x86/kernel/sys_x86_64.c:95 [inline]
 [<ffffffff81016bf6>] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:86
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
Code: a7 07 00 00 48 8b 45 c8 44 8b 28 48 b8 00 00 00 00 00 fc ff df 4a 8d 3c ed e0 6a 1a 83 4d 89 ec 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 70 07 00 00 48 8b 45 c8 4e 8b 2c ed e0 6a 1a 83 48 83 c0 
NMI backtrace for cpu 1
CPU: 1 PID: 20 Comm: khungtaskd Not tainted 4.4.174+ #4
task: ffff8801da6f4740 task.stack: ffff8800001d0000
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:62 [inline]
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] flat_send_IPI_mask+0xf7/0x1b0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800001d7c88  EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fc300
RBP: ffff8800001d7cb8 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000003000000 R14: ffffffff82e5f2e0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe0e229330 CR3: 00000000b4fb5000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000001 ffffffff82e5f2e0 ffffffff831a6ac0 fffffbfff0634c34
 000000000001b6c0 0000000000000008 ffff8800001d7cd8 ffffffff81092bee
 0000000000000008 ffffffff82924260 ffff8800001d7d30 ffffffff81ab8252
Call Trace:
 [<ffffffff81092bee>] nmi_raise_cpu_backtrace+0x5e/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81ab8252>] nmi_trigger_all_cpu_backtrace.cold+0xa1/0xae lib/nmi_backtrace.c:85
 [<ffffffff81092ca4>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff813b4762>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff813b4762>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813b4762>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813b4762>] watchdog.cold+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff811342c3>] kthread+0x273/0x310 kernel/kthread.c:211
 [<ffffffff82718fc5>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:537
Code: 00 c3 5f ff 80 e6 10 75 e1 41 c1 e5 18 44 89 2c 25 10 c3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 c3 5f ff <41> f7 c4 00 02 00 00 75 1e 4c 89 e7 57 9d 0f 1f 44 00 00 e8 f1