INFO: task syz.2.3889:18265 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.2.3889 state:D stack:0 pid:18265 tgid:18265 ppid:16524 task_flags:0x400040 flags:0x00000005 Call trace: [<81b1c6fc>] (__schedule) from [<81b1db90>] (__schedule_loop kernel/sched/core.c:7268 [inline]) [<81b1c6fc>] (__schedule) from [<81b1db90>] (schedule+0x2c/0x134 kernel/sched/core.c:7283) r10:85ea2a00 r9:848f5780 r8:863a7800 r7:84ff3c28 r6:eb1b5ea8 r5:eb1b5e50 r4:848f5780 [<81b1db64>] (schedule) from [<80783a2c>] (request_wait_answer fs/fuse/dev.c:590 [inline]) [<81b1db64>] (schedule) from [<80783a2c>] (__fuse_request_send fs/fuse/dev.c:604 [inline]) [<81b1db64>] (schedule) from [<80783a2c>] (__fuse_simple_request+0x3b8/0x520 fs/fuse/dev.c:699) r5:eb1b5e50 r4:84ff3bd0 [<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) r8:83386f80 r7:8607ab40 r6:83fea600 r5:85518fc0 r4:85ea2a00 [<8078ce28>] (fuse_flush) from [<80580abc>] (filp_flush+0x38/0x88 fs/open.c:1467) r8:83fea640 r7:85baa0c0 r6:0000001e r5:83fea600 r4:85ea2a00 [<80580a84>] (filp_flush) from [<80580b20>] (filp_close+0x14/0x28 fs/open.c:1480) r7:85baa0c0 r6:0000001e r5:85ea2a00 r4:83fea600 [<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 r4:83fea600 [<805b2c9c>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xeb1b5fa8 to 0xeb1b5ff0) 5fa0: 00000000 00000000 00000003 0000001e 00000000 7eb3e918 5fc0: 00000000 00000000 00000000 000001b4 001e62ab 00000001 00000000 00346384 5fe0: 7eb3e840 7eb3e830 0002853c 00130810 r10:000001b4 r9:848f5780 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: [<80201a14>] (dump_backtrace) from [<80201b08>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257) r7:60000193 r6:60000193 r5:8231dcdc 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 r6:00000113 r5:00000000 r4:00000001 [<8021e330>] (dump_stack) from [<81b05fd4>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:113) [<81b05e84>] (nmi_cpu_backtrace) from [<81b06124>] (nmi_trigger_cpumask_backtrace+0x130/0x1d8 lib/nmi_backtrace.c:62) r7:00000000 r6:82a0b550 r5:82a1a2b8 r4:ffffffff [<81b05ff4>] (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 r5:00007eea r4:00000048 [<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0dc70>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0dc70>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0dc70>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b0dc08>] (sys_info) from [<8038acc4>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b0dc08>] (sys_info) from [<8038acc4>] (watchdog+0x3ac/0x858 kernel/hung_task.c:561) r5:00007eea r4:00000001 [<8038a918>] (watchdog) from [<80281540>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e58 r8:83352680 r7:00000000 r6:8038a918 r5:833a0c80 r4:831f7480 [<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 r4:831f7480 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2821 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:616 [inline] LR is at pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2668 pc : [<81b26fb8>] lr : [<80ae1fac>] psr: 60000013 sp : eb399ec8 ip : eb399ed8 fp : eb399ed4 r10: 82b58bf4 r9 : 00000001 r8 : 00000000 r7 : 00000117 r6 : 82b58b58 r5 : 00000000 r4 : 00000001 r3 : 00003247 r2 : 00000000 r1 : 60000013 r0 : 846f8840 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 8b796c00 DAC: 00000000 Call trace: [<81b26f90>] (_raw_spin_unlock_irqrestore) from [<80ae1fac>] (spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]) [<81b26f90>] (_raw_spin_unlock_irqrestore) from [<80ae1fac>] (__uart_port_unlock_irqrestore include/linux/serial_core.h:616 [inline]) [<81b26f90>] (_raw_spin_unlock_irqrestore) from [<80ae1fac>] (pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2668) [<80ae1f8c>] (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 r4:8465f080 [<802e8b50>] (nbcon_kthread_func) from [<80281540>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:e44c1b38 r8:84c64c80 r7:82b58b58 r6:802e8b50 r5:8465f080 r4:8337d3c0 [<80281424>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xeb399fb0 to 0xeb399ff8) 9fa0: 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80281424 r4:8337d3c0