INFO: task syz.4.8684:5502 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.4.8684 state:D stack:0 pid:5502 tgid:5502 ppid:4787 task_flags:0x400040 flags:0x00000005 Call trace: [<81b71894>] (__schedule) from [<81b72d2c>] (__schedule_loop kernel/sched/core.c:7311 [inline]) [<81b71894>] (__schedule) from [<81b72d2c>] (schedule+0x2c/0xec kernel/sched/core.c:7326) r10:8643d480 r9:84873100 r8:869fb000 r7:84e672f8 r6:dfc7dea0 r5:dfc7de30 r4:84873100 [<81b72d00>] (schedule) from [<807a50cc>] (request_wait_answer fs/fuse/dev.c:743 [inline]) [<81b72d00>] (schedule) from [<807a50cc>] (__fuse_request_send fs/fuse/dev.c:757 [inline]) [<81b72d00>] (schedule) from [<807a50cc>] (fuse_chan_send+0x390/0x47c fs/fuse/dev.c:833) r5:dfc7de30 r4:84e672a0 [<807a4d3c>] (fuse_chan_send) from [<807b7554>] (__fuse_simple_request+0x5c/0x68 fs/fuse/req.c:69) r8:86927880 r7:85745800 r6:831de100 r5:86e49cc0 r4:dfc7dea0 [<807b74f8>] (__fuse_simple_r [<807b74f8>] (__fuse_simple_request) from [<807acd84>] (fuse_simple_request fs/fuse/fuse_i.h:1012 [inline]) [<807b74f8>] (__fuse_simple_request) from [<807acd84>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:504) r5:85cae900 r4:8643d480 [<807acc0c>] (fuse_flush) from [<8059af04>] (filp_flush+0x38/0x88 fs/open.c:1520) r8:831de140 r7:86a63bc0 r6:0000001e r5:831de100 r4:8643d480 [<8059aecc>] (filp_flush) from [<8059af68>] (filp_close+0x14/0x28 fs/open.c:1533) r7:86a63bc0 r6:0000001e r5:8643d480 r4:831de100 [<8059af54>] (filp_close) from [<805ced90>] (__range_close fs/file.c:793 [inline]) [<8059af54>] (filp_close) from [<805ced90>] (__do_sys_close_range fs/file.c:854 [inline]) [<8059af54>] (filp_close) from [<805ced90>] (sys_close_range+0x18c/0x224 fs/file.c:818) r5:00000004 r4:831de100 [<805cec04>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfc7dfa8 to 0xdfc7dff0) dfa0: 00000000 00000000 00000003 0000001e 00000000 7eb54920 dfc0: 00000000 00000000 00000000 000001b4 7eb54920 00000000 00000000 003562e4 dfe0: 7eb54848 7eb54838 00028610 001309d0 r10:000001b4 r9:84873100 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 r5:82336570 r4:00000000 [<80201a74>] (show_stack) from [<8021ec68>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201a74>] (show_stack) from [<8021ec68>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021ec0c>] (dump_stack_lvl) from [<8021ec94>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:00000000 r6:00000113 r5:00000000 r4:00000001 [<8021ec7c>] (dump_stack) from [<81b5aefc>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:122) [<81b5adac>] (nmi_cpu_backtrace) from [<81b5b050>] (nmi_trigger_cpumask_backtrace+0x134/0x208 lib/nmi_backtrace.c:65) r7:82a0b150 r6:83818c40 r5:82a1c7b8 r4:ffffffff [<81b5af1c>] (nmi_trigger_cpumask_backtrace) from [<802300d4>] (arch_trigger_cpumask_backtrace+0x18/0x1c arch/arm/kernel/smp.c:851) r9:82a0b2f0 r8:00000001 r7:82a1ce80 r6:82ccce2c r5:00007f02 r4:00000048 [<802300bc>] (arch_trigger_cpumask_backtrace) from [<81b62b8c>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<802300bc>] (arch_trigger_cpumask_backtrace) from [<81b62b8c>] (__sys_info lib/sys_info.c:157 [inline]) [<802300bc>] (arch_trigger_cpumask_backtrace) from [<81b62b8c>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b62b24>] (sys_info) from [<80390a60>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b62b24>] (sys_info) from [<80390a60>] (watchdog+0x3a0/0x848 kernel/hung_task.c:561) r5:00007f02 r4:0000000a [<803906c0>] (watchdog) from [<802827b4>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e60 r8:831dbe80 r7:00000000 r6:803906c0 r5:83818c40 r4:83359b00 [<80282698>] (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 r5:80282698 r4:83359b00 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:2720 pc : [<81b7c1f4>] lr : [<80b0d95c>] psr: 60000113 sp : eb201ec8 ip : eb201ed8 fp : eb201ed4 r10: 82b5e31c r9 : 00000001 r8 : 00000000 r7 : 00000117 r6 : 82b5e280 r5 : 00000000 r4 : 00000001 r3 : 00006a2c r2 : 00000000 r1 : 60000113 r0 : 84d43440 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 857579c0 DAC: 00000000 Call trace: [<81b7c1cc>] (_raw_spin_unlock_irqrestore) from [<80b0d95c>] (spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]) [<81b7c1cc>] (_raw_spin_unlock_irqrestore) from [<80b0d95c>] (__uart_port_unlock_irqrestore include/linux/serial_core.h:618 [inline]) [<81b7c1cc>] (_raw_spin_unlock_irqrestore) from [<80b0d95c>] (pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2720) [<80b0d93c>] (pl011_console_device_unlock) from [<802ed2c8>] (nbcon_emit_one+0x88/0x100 kernel/printk/nbcon.c:1165) [<802ed240>] (nbcon_emit_one) from [<802ed548>] (nbcon_kthread_func+0x208/0x2ec kernel/printk/nbcon.c:1271) r6:82cc92ec r5:82b5e280 r4:83fe6e40 [<802ed340>] (nbcon_kthread_func) from [<802827b4>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df9a9b38 r8:84758880 r7:82b5e280 r6:802ed340 r5:83fe6e40 r4:84dd8380 [<80282698>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xeb201fb0 to 0xeb201ff8) 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 r5:80282698 r4:84dd8380