INFO: task syz.2.4565:20435 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.2.4565 state:D stack:0 pid:20435 tgid:20435 ppid:17242 task_flags:0x400040 flags:0x00000005 Call trace: [<81b5c57c>] (__schedule) from [<81b5da14>] (__schedule_loop kernel/sched/core.c:7311 [inline]) [<81b5c57c>] (__schedule) from [<81b5da14>] (schedule+0x2c/0xec kernel/sched/core.c:7326) r10:83adc700 r9:858724c0 r8:8646e300 r7:84b3e4b8 r6:eab8dea0 r5:eab8de30 r4:858724c0 [<81b5d9e8>] (schedule) from [<8079fbe0>] (request_wait_answer fs/fuse/dev.c:743 [inline]) [<81b5d9e8>] (schedule) from [<8079fbe0>] (__fuse_request_send fs/fuse/dev.c:757 [inline]) [<81b5d9e8>] (schedule) from [<8079fbe0>] (fuse_chan_send+0x390/0x47c fs/fuse/dev.c:833) r5:eab8de30 r4:84b3e460 [<8079f850>] (fuse_chan_send) from [<807b2138>] (__fuse_simple_request+0x5c/0x68 fs/fuse/req.c:69) r8:8690e680 r7:867e9000 r6:84a97900 r5:845c7000 r4:eab8dea0 [<807b20dc>] (__fuse_simple_request) from [<807a78d4>] (fuse_simple_request fs/fuse/fuse_i.h:1012 [inline]) [<807b20dc>] (__fuse_simple_request) from [<807a78d4>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:504) r5:8504d200 r4:83adc700 [<807a775c>] (fuse_flush) from [<805997b0>] (filp_flush+0x38/0x88 fs/open.c:1471) r8:84a97940 r7:862cbe40 r6:0000001e r5:84a97900 r4:83adc700 [<80599778>] (filp_flush) from [<80599814>] (filp_close+0x14/0x28 fs/open.c:1484) r7:862cbe40 r6:0000001e r5:83adc700 r4:84a97900 [<80599800>] (filp_close) from [<805cbdbc>] (__range_close fs/file.c:793 [inline]) [<80599800>] (filp_close) from [<805cbdbc>] (__do_sys_close_range fs/file.c:854 [inline]) [<80599800>] (filp_close) from [<805cbdbc>] (sys_close_range+0x18c/0x224 fs/file.c:818) r5:00000007 r4:84a97900 [<805cbc30>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xeab8dfa8 to 0xeab8dff0) dfa0: 00000000 00000000 00000003 0000001e 00000000 7ee01918 dfc0: 00000000 00000000 00000000 000001b4 7ee01918 00000000 00000000 00356384 dfe0: 7ee01840 7ee01830 0002853c 001308d0 r10:000001b4 r9:858724c0 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) r7:60000193 r6:60000193 r5:82332b74 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 r5:00000001 r4:00000001 [<8021e594>] (dump_stack) from [<81b45c1c>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:122) [<81b45acc>] (nmi_cpu_backtrace) from [<81b45d70>] (nmi_trigger_cpumask_backtrace+0x134/0x208 lib/nmi_backtrace.c:65) r7:82a0b150 r6:83178000 r5:82a1c7b8 r4:ffffffff [<81b45c3c>] (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 r5:00007f1d r4:00000048 [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4d8ac>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4d8ac>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b4d8ac>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b4d844>] (sys_info) from [<8038f838>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b4d844>] (sys_info) from [<8038f838>] (watchdog+0x3a0/0x848 kernel/hung_task.c:561) r5:00007f1d r4:0000000a [<8038f498>] (watchdog) from [<80281710>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e60 r8:83110f00 r7:00000000 r6:8038f498 r5:83178000 r4:8388a180 [<802815f4>] (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 r5:802815f4 r4:8388a180 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 24980 Comm: syz.5.5697 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express PC is at uaccess_save_and_enable arch/arm/include/asm/uaccess.h:59 [inline] PC is at setup_sigframe+0x178/0x1c8 arch/arm/kernel/signal.c:295 LR is at 0x0 pc : [<8022a1d8>] lr : [<00000000>] psr: 40000013 sp : ea7c5ea8 ip : 00000020 fp : ea7c5f34 r10: 00000000 r9 : 000000f0 r8 : 7e92a918 r7 : b5403587 r6 : 00000000 r5 : b5403587 r4 : 7e92a538 r3 : b5003500 r2 : 00000000 r1 : 00000000 r0 : 7e92a740 Flags: nZcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 878158c0 DAC: fffffffd Call trace: [<8022a060>] (setup_sigframe) from [<8022a8c0>] (setup_rt_frame arch/arm/kernel/signal.c:483 [inline]) [<8022a060>] (setup_sigframe) from [<8022a8c0>] (handle_signal arch/arm/kernel/signal.c:517 [inline]) [<8022a060>] (setup_sigframe) from [<8022a8c0>] (do_signal arch/arm/kernel/signal.c:590 [inline]) [<8022a060>] (setup_sigframe) from [<8022a8c0>] (do_work_pending+0x3b4/0x4f0 arch/arm/kernel/signal.c:619) r10:b5403587 r9:7e92a538 r8:00000000 r7:8385392c r6:7e92a4b8 r5:ea7c5fb0 r4:83853100 [<8022a50c>] (do_work_pending) from [<80200088>] (slow_work_pending+0xc/0x24) Exception stack(0xea7c5fb0 to 0xea7c5ff8) 5fa0: ffffff92 00000080 00000000 7e92a918 5fc0: 00000000 00000000 00000000 000000f0 7e92a918 000001f4 00000000 003562e4 5fe0: 7e92a840 7e92a830 000291f0 001308d0 20000010 00000384 r10:000000ad r9:83853100 r8:00000000 r7:000000ad r6:00000000 r5:00000000 r4:00000000