INFO: task syz.4.3224:27390 blocked for more than 430 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.3224 state:D stack:0 pid:27390 tgid:27390 ppid:26165 task_flags:0x400040 flags:0x00000005 Call trace: [<81b599bc>] (__schedule) from [<81b5ae54>] (__schedule_loop kernel/sched/core.c:7311 [inline]) [<81b599bc>] (__schedule) from [<81b5ae54>] (schedule+0x2c/0xec kernel/sched/core.c:7326) r10:86a96380 r9:839c55c0 r8:86034000 r7:850b7ad8 r6:dfb59ea0 r5:dfb59e30 r4:839c55c0 [<81b5ae28>] (schedule) from [<8079f220>] (request_wait_answer fs/fuse/dev.c:743 [inline]) [<81b5ae28>] (schedule) from [<8079f220>] (__fuse_request_send fs/fuse/dev.c:757 [inline]) [<81b5ae28>] (schedule) from [<8079f220>] (fuse_chan_send+0x390/0x47c fs/fuse/dev.c:833) r5:dfb59e30 r4:850b7a80 [<8079ee90>] (fuse_chan_send) from [<807b1778>] (__fuse_simple_request+0x5c/0x68 fs/fuse/req.c:69) r8:8330a480 r7:85e53a00 r6:8665a500 r5:85fbacc0 r4:dfb59ea0 [<807b171c>] (__fuse_simple_request) from [<807a6f14>] (fuse_simple_request fs/fuse/fuse_i.h:1012 [inline]) [<807b171c>] (__fuse_simple_request) from [<807a6f14>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:504) r5:8594e900 r4:86a96380 [<807a6d9c>] (fuse_flush) from [<80599470>] (filp_flush+0x38/0x88 fs/open.c:1471) r8:8665a540 r7:8725bfc0 r6:0000001e r5:8665a500 r4:86a96380 [<80599438>] (filp_flush) from [<805994d4>] (filp_close+0x14/0x28 fs/open.c:1484) r7:8725bfc0 r6:0000001e r5:86a96380 r4:8665a500 [<805994c0>] (filp_close) from [<805cba7c>] (__range_close fs/file.c:793 [inline]) [<805994c0>] (filp_close) from [<805cba7c>] (__do_sys_close_range fs/file.c:854 [inline]) [<805994c0>] (filp_close) from [<805cba7c>] (sys_close_range+0x18c/0x224 fs/file.c:818) r5:00000008 r4:8665a500 [<805cb8f0>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfb59fa8 to 0xdfb59ff0) 9fa0: 00000000 00000000 00000003 0000001e 00000000 7ef14918 9fc0: 00000000 00000000 00000000 000001b4 7ef14918 00000000 00000000 003562e4 9fe0: 7ef14840 7ef14830 0002853c 00130820 r10:000001b4 r9:839c55c0 r8:8020029c r7:000001b4 r6:00000000 r5:00000000 r4:00000000 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 29 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express Call trace: [<80201998>] (dump_backtrace) from [<80201a8c>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257) r7:60000193 r6:60000193 r5:82332568 r4:00000000 [<80201a74>] (show_stack) from [<8021e580>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201a74>] (show_stack) from [<8021e580>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021e524>] (dump_stack_lvl) from [<8021e5ac>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:00000000 r6:00000113 r5:00000000 r4:00000001 [<8021e594>] (dump_stack) from [<81b4305c>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:122) [<81b42f0c>] (nmi_cpu_backtrace) from [<81b431b0>] (nmi_trigger_cpumask_backtrace+0x134/0x208 lib/nmi_backtrace.c:65) r7:82a0b150 r6:83320c40 r5:82a1c7b8 r4:ffffffff [<81b4307c>] (nmi_trigger_cpumask_backtrace) from [<8022f0f4>] (arch_trigger_cpumask_backtrace+0x18/0x1c arch/arm/kernel/smp.c:851) r9:82a0b2f0 r8:00000001 r7:82a1ce80 r6:82ccae2c r5:00007ee5 r4:00000048 [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4acec>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4acec>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4acec>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b4ac84>] (sys_info) from [<8038f854>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b4ac84>] (sys_info) from [<8038f854>] (watchdog+0x3a0/0x848 kernel/hung_task.c:561) r5:00007ee5 r4:0000000a [<8038f4b4>] (watchdog) from [<80281700>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e60 r8:831d5c00 r7:00000000 r6:8038f4b4 r5:83320c40 r4:833e0ac0 [<802815e4>] (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 r5:802815e4 r4:833e0ac0 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2826 Comm: pr/ttyAMA-1 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP 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:618 [inline] LR is at pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2700 pc : [<81b6431c>] lr : [<80b01084>] psr: 600b0013 sp : eb0e1ec8 ip : eb0e1ed8 fp : eb0e1ed4 r10: 82b5cd1c r9 : 00000001 r8 : 00000000 r7 : 00000117 r6 : 82b5cc80 r5 : 00000000 r4 : 00000001 r3 : 0000311b r2 : 00000000 r1 : 600b0013 r0 : 84893040 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 86c72e40 DAC: 00000000 Call trace: [<81b642f4>] (_raw_spin_unlock_irqrestore) from [<80b01084>] (spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]) [<81b642f4>] (_raw_spin_unlock_irqrestore) from [<80b01084>] (__uart_port_unlock_irqrestore include/linux/serial_core.h:618 [inline]) [<81b642f4>] (_raw_spin_unlock_irqrestore) from [<80b01084>] (pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2700) [<80b01064>] (pl011_console_device_unlock) from [<802ec158>] (nbcon_emit_one+0x88/0x100 kernel/printk/nbcon.c:1165) [<802ec0d0>] (nbcon_emit_one) from [<802ec3d8>] (nbcon_kthread_func+0x208/0x2ec kernel/printk/nbcon.c:1271) r6:82cc72ec r5:82b5cc80 r4:83f9d5c0 [<802ec1d0>] (nbcon_kthread_func) from [<80281700>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df931b38 r8:84cad580 r7:82b5cc80 r6:802ec1d0 r5:83f9d5c0 r4:8502db40 [<802815e4>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xeb0e1fb0 to 0xeb0e1ff8) 1fa0: 00000000 00000000 00000000 00000000 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:802815e4 r4:8502db40