INFO: task syz.0.229:4425 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.0.229 state:D stack:0 pid:4425 tgid:4425 ppid:3104 task_flags:0x400040 flags:0x00000005 Call trace: [<81b576dc>] (__schedule) from [<81b58b74>] (__schedule_loop kernel/sched/core.c:7311 [inline]) [<81b576dc>] (__schedule) from [<81b58b74>] (schedule+0x2c/0xec kernel/sched/core.c:7326) r10:86106400 r9:8402bd40 r8:862c7800 r7:8556e528 r6:e44c9ea0 r5:e44c9e30 r4:8402bd40 [<81b58b48>] (schedule) from [<8079e68c>] (request_wait_answer fs/fuse/dev.c:743 [inline]) [<81b58b48>] (schedule) from [<8079e68c>] (__fuse_request_send fs/fuse/dev.c:757 [inline]) [<81b58b48>] (schedule) from [<8079e68c>] (fuse_chan_send+0x390/0x47c fs/fuse/dev.c:833) r5:e44c9e30 r4:8556e4d0 [<8079e2fc>] (fuse_chan_send) from [<807b0bf4>] (__fuse_simple_request+0x5c/0x68 fs/fuse/req.c:69) r8:85fc8a80 r7:8618c940 r6:8495f500 r5:85fd5000 r4:e44c9ea0 [<807b0b98>] (__fuse_simple_request) from [<807a6390>] (fuse_simple_request fs/fuse/fuse_i.h:1012 [inline]) [<807b0b98>] (__fuse_simple_request) from [<807a6390>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:504) r5:837c58c0 r4:86106400 [<807a6218>] (fuse_flush) from [<8059918c>] (filp_flush+0x38/0x88 fs/open.c:1471) r8:8495f540 r7:86015e00 r6:0000001e r5:8495f500 r4:86106400 [<80599154>] (filp_flush) from [<805991f0>] (filp_close+0x14/0x28 fs/open.c:1484) r7:86015e00 r6:0000001e r5:86106400 r4:8495f500 [<805991dc>] (filp_close) from [<805cb714>] (__range_close fs/file.c:793 [inline]) [<805991dc>] (filp_close) from [<805cb714>] (__do_sys_close_range fs/file.c:854 [inline]) [<805991dc>] (filp_close) from [<805cb714>] (sys_close_range+0x18c/0x224 fs/file.c:818) r5:00000008 r4:8495f500 [<805cb588>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xe44c9fa8 to 0xe44c9ff0) 9fa0: 00000000 00000000 00000003 0000001e 00000000 7eb50918 9fc0: 00000000 00000000 00000000 000001b4 00026e4a ffffffff 00000000 003562e4 9fe0: 7eb50840 7eb50830 0002853c 00130820 r10:000001b4 r9:8402bd40 r8:8020029c r7:000001b4 r6:00000000 r5:00000000 r4:00000000 NMI backtrace for cpu 1 CPU: 1 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) r7:600d0093 r6:600d0093 r5:82332258 r4:00000000 [<80201a74>] (show_stack) from [<8021e5e0>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201a74>] (show_stack) from [<8021e5e0>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021e584>] (dump_stack_lvl) from [<8021e60c>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:00000000 r6:000d0013 r5:00000001 r4:00000001 [<8021e5f4>] (dump_stack) from [<81b40d7c>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:122) [<81b40c2c>] (nmi_cpu_backtrace) from [<81b40ed0>] (nmi_trigger_cpumask_backtrace+0x134/0x208 lib/nmi_backtrace.c:65) r7:82a0b150 r6:83380000 r5:82a1c7b8 r4:ffffffff [<81b40d9c>] (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 r5:00007f3e r4:00000048 [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b48a0c>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b48a0c>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b48a0c>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b489a4>] (sys_info) from [<8038f87c>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b489a4>] (sys_info) from [<8038f87c>] (watchdog+0x3a0/0x848 kernel/hung_task.c:561) r5:00007f3e r4:0000000a [<8038f4dc>] (watchdog) from [<80281708>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e60 r8:83110880 r7:00000000 r6:8038f4dc r5:83380000 r4:8387c640 [<802815ec>] (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 r5:802815ec r4:8387c640 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2823 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 : [<81b6203c>] lr : [<80b00484>] psr: 60000013 sp : eb351ec8 ip : eb351ed8 fp : eb351ed4 r10: 82b5cd1c r9 : 00000000 r8 : 00000000 r7 : 00000117 r6 : 82b5cc80 r5 : 00000000 r4 : 00000001 r3 : 00000fc1 r2 : 00000000 r1 : 60000013 r0 : 84562040 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 85790840 DAC: fffffffd Call trace: [<81b62014>] (_raw_spin_unlock_irqrestore) from [<80b00484>] (spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]) [<81b62014>] (_raw_spin_unlock_irqrestore) from [<80b00484>] (__uart_port_unlock_irqrestore include/linux/serial_core.h:618 [inline]) [<81b62014>] (_raw_spin_unlock_irqrestore) from [<80b00484>] (pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2700) [<80b00464>] (pl011_console_device_unlock) from [<802ec160>] (nbcon_emit_one+0x88/0x100 kernel/printk/nbcon.c:1165) [<802ec0d8>] (nbcon_emit_one) from [<802ec3e0>] (nbcon_kthread_func+0x208/0x2ec kernel/printk/nbcon.c:1271) r6:82cc72ec r5:82b5cc80 r4:8474ee40 [<802ec1d8>] (nbcon_kthread_func) from [<80281708>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:eaea5b38 r8:84e06d80 r7:82b5cc80 r6:802ec1d8 r5:8474ee40 r4:84defcc0 [<802815ec>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xeb351fb0 to 0xeb351ff8) 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 r5:802815ec r4:84defcc0