INFO: task syz-executor525:3792 blocked for more than 120 seconds.
      Not tainted 4.4.138-gcf21a9a #64
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor525 D ffff8801cd687a68 27856  3792   3789 0x00000000
 ffff8801cd687a68 0000000000000000 ffff8801cd3550e0 ffffed0039a6aa1b
 ffff8801cd354800 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8
 ffff8801db21f4c0 ffffffff84417840 ffff8801cd354800 0000000000000000
Call Trace:
 [<ffffffff838b46ea>] schedule+0x7a/0x1b0 kernel/sched/core.c:3359
 [<ffffffff838b4e83>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3392
 [<ffffffff838bafc7>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff838bafc7>] mutex_lock_nested+0x307/0x850 kernel/locking/mutex.c:621
 [<ffffffff8251bc0b>] lo_ioctl+0x8b/0x1ad0 drivers/block/loop.c:1355
 [<ffffffff81db7f68>] __blkdev_driver_ioctl block/ioctl.c:288 [inline]
 [<ffffffff81db7f68>] blkdev_ioctl+0x7b8/0x19c0 block/ioctl.c:584
 [<ffffffff815d3fce>] block_ioctl+0xde/0x120 fs/block_dev.c:1625
 [<ffffffff81559c8f>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff81559c8f>] file_ioctl fs/ioctl.c:470 [inline]
 [<ffffffff81559c8f>] do_vfs_ioctl+0x63f/0xf40 fs/ioctl.c:605
 [<ffffffff8155a61f>] SYSC_ioctl fs/ioctl.c:622 [inline]
 [<ffffffff8155a61f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:613
 [<ffffffff838c2725>] entry_SYSCALL_64_fastpath+0x22/0x9e
1 lock held by syz-executor525/3792:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff8251bc0b>] lo_ioctl+0x8b/0x1ad0 drivers/block/loop.c:1355
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 3789 Comm: sshd Not tainted 4.4.138-gcf21a9a #64
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cd351800 task.stack: ffff8801d8f08000
RIP: 0010:[<ffffffff812db621>]  [<ffffffff812db621>] __module_address+0x341/0x460 kernel/module.c:4088
RSP: 0018:ffff8801db2074b0  EFLAGS: 00000286
RAX: 0000000000000102 RBX: 0000563cf4233af0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff812ae8e1 RDI: 0000563cf4233af0
RBP: ffff8801db2074d0 R08: ffff8801db207600 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffffff8000
R13: 0000563cf4233af0 R14: ffff8801d8f0fe28 R15: 0000000000000000
FS:  00007f648b8d67c0(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f98718000 CR3: 00000001ccc77000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff812db753 ffffffff8423f968 0000563cf4233af0 ffffffffffff8000
 ffff8801db2074e8 ffffffff812e926a 0000563cf4233af0 ffff8801db207500
 ffffffff8118bf4b ffff8801d8f0fe60 ffff8801db207558 ffffffff810167cb
Call Trace:
 [<ffffffff812e926a>] is_module_text_address+0x1a/0x50 kernel/module.c:4104
 [<ffffffff8118bf4b>] __kernel_text_address+0x6b/0xa0 kernel/extable.c:103
 [<ffffffff810167cb>] print_context_stack+0x4b/0xd0 arch/x86/kernel/dumpstack.c:107
 [<ffffffff81015d0a>] dump_trace+0x17a/0x360 arch/x86/kernel/dumpstack_64.c:243
 [<ffffffff81033e46>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814f88d3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814f8bb7>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814f8bb7>] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616
 [<ffffffff814f9182>] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554
 [<ffffffff814f4c7e>] slab_post_alloc_hook mm/slub.c:1349 [inline]
 [<ffffffff814f4c7e>] slab_alloc_node mm/slub.c:2615 [inline]
 [<ffffffff814f4c7e>] slab_alloc mm/slub.c:2623 [inline]
 [<ffffffff814f4c7e>] kmem_cache_alloc+0xbe/0x2a0 mm/slub.c:2628
 [<ffffffff82f3d470>] skb_clone+0x140/0x2c0 net/core/skbuff.c:957
 [<ffffffff835726ac>] skb_share_check include/linux/skbuff.h:1312 [inline]
 [<ffffffff835726ac>] packet_rcv_spkt+0x3ac/0x4c0 net/packet/af_packet.c:1812
 [<ffffffff82f7e1f5>] deliver_skb net/core/dev.c:1820 [inline]
 [<ffffffff82f7e1f5>] deliver_ptype_list_skb net/core/dev.c:1835 [inline]
 [<ffffffff82f7e1f5>] __netif_receive_skb_core+0x9c5/0x2940 net/core/dev.c:4002
 [<ffffffff82f801cb>] __netif_receive_skb+0x5b/0x1b0 net/core/dev.c:4054
 [<ffffffff82f80411>] netif_receive_skb_internal+0xf1/0x3a0 net/core/dev.c:4082
 [<ffffffff82f837bf>] napi_skb_finish net/core/dev.c:4417 [inline]
 [<ffffffff82f837bf>] napi_gro_receive+0x15f/0x420 net/core/dev.c:4446
 [<ffffffff8275e5b4>] virtnet_receive+0
NMI backtrace for cpu 1
CPU: 1 PID: 491 Comm: khungtaskd Not tainted 4.4.138-gcf21a9a #64
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d8c49800 task.stack: ffff8801d8e10000
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] flat_send_IPI_mask+0xf6/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8801d8e17cc8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8801d8e17cf0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: 0000000000000002 R15: ffffffff8446f6a0
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f98718000 CR3: 00000001cf48d000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8446f6a0 ffffffff84a18ee0 0000000000000007 fffffbfff0942c8c
 0000000000000040 ffff8801d8e17d10 ffffffff810b5ae1 ffffffff83c0b460
 0000000000000003 ffff8801d8e17d68 ffffffff81e19d83 ffffffff8140dd6f
Call Trace:
 [<ffffffff810b5ae1>] nmi_raise_cpu_backtrace+0x61/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81e19d83>] nmi_trigger_all_cpu_backtrace.cold.4+0x70/0xad lib/nmi_backtrace.c:85
 [<ffffffff810b5b84>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff8141a459>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff8141a459>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8141a459>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8141a459>] watchdog.cold.1+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff81190958>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff838c2b55>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510
Code: b3 5f ff f6 c4 10 75 e2 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 f2 09 da 80 cf 04 41 83 fe 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 75 1a 4c 89 e7 57 9d 0f 1f 44 00 00 e8 02