INFO: task syz.1.1276:8273 blocked for more than 430 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1276      state:D stack:0     pid:8273  tgid:8273  ppid:7858   task_flags:0x400040 flags:0x00000005
Call trace: 
[<81b1d6fc>] (__schedule) from [<81b1eb90>] (__schedule_loop kernel/sched/core.c:7268 [inline])
[<81b1d6fc>] (__schedule) from [<81b1eb90>] (schedule+0x2c/0x134 kernel/sched/core.c:7283)
 r10:85e70880 r9:83ff7080 r8:85f38a00 r7:84cf9598 r6:dfb39ea8 r5:dfb39e50
 r4:83ff7080
[<81b1eb64>] (schedule) from [<80783a2c>] (request_wait_answer fs/fuse/dev.c:590 [inline])
[<81b1eb64>] (schedule) from [<80783a2c>] (__fuse_request_send fs/fuse/dev.c:604 [inline])
[<81b1eb64>] (schedule) from [<80783a2c>] (__fuse_simple_request+0x3b8/0x520 fs/fuse/dev.c:699)
 r5:dfb39e50 r4:84cf9540
[<80783674>] (__fuse_simple_request) from [<8078cfa0>] (fuse_simple_request fs/fuse/fuse_i.h:1262 [inline])
[<80783674>] (__fuse_simple_request) from [<8078cfa0>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:500)
 r8:85e71080 r7:85641d80 r6:8394fb00 r5:8597d8c0 r4:85e70880
[<8078ce28>] (fuse_flush) from [<80580abc>] (filp_flush+0x38/0x88 fs/open.c:1467)
 r8:8394fb40 r7:86260ac0 r6:0000001e r5:8394fb00 r4:85e70880
[<80580a84>] (filp_flush) from [<80580b20>] (filp_close+0x14/0x28 fs/open.c:1480)
 r7:86260ac0 r6:0000001e r5:85e70880 r4:8394fb00
[<80580b0c>] (filp_close) from [<805b2e28>] (__range_close fs/file.c:794 [inline])
[<80580b0c>] (filp_close) from [<805b2e28>] (__do_sys_close_range fs/file.c:855 [inline])
[<80580b0c>] (filp_close) from [<805b2e28>] (sys_close_range+0x18c/0x224 fs/file.c:819)
 r5:00000005 r4:8394fb00
[<805b2c9c>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67)
Exception stack(0xdfb39fa8 to 0xdfb39ff0)
9fa0:                   00000000 00000000 00000003 0000001e 00000000 7e894918
9fc0: 00000000 00000000 00000000 000001b4 000d0a88 ffffffff 00000000 00346424
9fe0: 7e894840 7e894830 0002853c 00130810
 r10:000001b4 r9:83ff7080 r8:8020029c r7:000001b4 r6:00000000 r5:00000000
 r4:00000000
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT 
Hardware name: ARM-Versatile Express
Call trace: 
[<80201a14>] (dump_backtrace) from [<80201b08>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257)
 r7:60000093 r6:60000093 r5:8231ddd4 r4:00000000
[<80201af0>] (show_stack) from [<8021e31c>] (__dump_stack lib/dump_stack.c:94 [inline])
[<80201af0>] (show_stack) from [<8021e31c>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120)
[<8021e2c0>] (dump_stack_lvl) from [<8021e348>] (dump_stack+0x18/0x1c lib/dump_stack.c:129)
 r7:00000000 r6:00000013 r5:00000000 r4:00000001
[<8021e330>] (dump_stack) from [<81b06fd4>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:113)
[<81b06e84>] (nmi_cpu_backtrace) from [<81b07124>] (nmi_trigger_cpumask_backtrace+0x130/0x1d8 lib/nmi_backtrace.c:62)
 r7:00000000 r6:82a0b550 r5:82a1a2b8 r4:ffffffff
[<81b06ff4>] (nmi_trigger_cpumask_backtrace) from [<8022f104>] (arch_trigger_cpumask_backtrace+0x18/0x1c arch/arm/kernel/smp.c:852)
 r9:82a0b6d8 r8:00000048 r7:0000000a r6:82a03d80 r5:00007f15 r4:00000048
[<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0ec70>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline])
[<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0ec70>] (__sys_info lib/sys_info.c:157 [inline])
[<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0ec70>] (sys_info+0x68/0xa8 lib/sys_info.c:165)
[<81b0ec08>] (sys_info) from [<8038acc4>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline])
[<81b0ec08>] (sys_info) from [<8038acc4>] (watchdog+0x3ac/0x858 kernel/hung_task.c:561)
 r5:00007f15 r4:00000001
[<8038a918>] (watchdog) from [<80281540>] (kthread+0x11c/0x154 kernel/kthread.c:436)
 r10:00000000 r9:df819e58 r8:83352a00 r7:00000000 r6:8038a918 r5:833a0000
 r4:8383de40
[<80281424>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137)
Exception stack(0xdf8d5fb0 to 0xdf8d5ff8)
5fa0:                                     00000000 00000000 00000000 00000000
5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80281424 r4:8383de40
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 2818 Comm: pr/ttyAMA-1 Not tainted syzkaller #0 PREEMPT 
Hardware name: ARM-Versatile Express
PC is at __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
PC is at _raw_spin_unlock_irqrestore+0x28/0x54 kernel/locking/spinlock.c:198
LR is at spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
LR is at __uart_port_unlock_irqrestore include/linux/serial_core.h:616 [inline]
LR is at pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2668
pc : [<81b27fb8>]    lr : [<80ae1fec>]    psr: 600f0113
sp : eb1e5ec8  ip : eb1e5ed8  fp : eb1e5ed4
r10: 82b58bf4  r9 : 00000001  r8 : 00000000
r7 : 00000117  r6 : 82b58b58  r5 : 00000000  r4 : 00000001
r3 : 00002673  r2 : 00000000  r1 : 600f0113  r0 : 84531040
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 30c5387d  Table: 86a50040  DAC: 00000000
Call trace: 
[<81b27f90>] (_raw_spin_unlock_irqrestore) from [<80ae1fec>] (spin_unlock_irqrestore include/linux/spinlock.h:408 [inline])
[<81b27f90>] (_raw_spin_unlock_irqrestore) from [<80ae1fec>] (__uart_port_unlock_irqrestore include/linux/serial_core.h:616 [inline])
[<81b27f90>] (_raw_spin_unlock_irqrestore) from [<80ae1fec>] (pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2668)
[<80ae1fcc>] (pl011_console_device_unlock) from [<802e8ad8>] (nbcon_emit_one+0x88/0x100 kernel/printk/nbcon.c:1165)
[<802e8a50>] (nbcon_emit_one) from [<802e8d58>] (nbcon_kthread_func+0x208/0x2ec kernel/printk/nbcon.c:1271)
 r6:82cbf2d4 r5:82b58b58 r4:84663200
[<802e8b50>] (nbcon_kthread_func) from [<80281540>] (kthread+0x11c/0x154 kernel/kthread.c:436)
 r10:00000000 r9:df8ddb38 r8:84c56180 r7:82b58b58 r6:802e8b50 r5:84663200
 r4:845fb240
[<80281424>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137)
Exception stack(0xeb1e5fb0 to 0xeb1e5ff8)
5fa0:                                     00000000 00000000 00000000 00000000
5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80281424 r4:845fb240