INFO: task syz.3.2469:14087 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.3.2469 state:D stack:0 pid:14087 tgid:14087 ppid:12937 task_flags:0x400040 flags:0x00000005 Call trace: [<81aea14c>] (__schedule) from [<81aeb560>] (__schedule_loop kernel/sched/core.c:6993 [inline]) [<81aea14c>] (__schedule) from [<81aeb560>] (schedule+0x2c/0x134 kernel/sched/core.c:7008) r10:86bca6c0 r9:85103100 r8:87791e00 r7:84e38288 r6:dfaf5ea8 r5:dfaf5e50 r4:85103100 [<81aeb534>] (schedule) from [<807692c0>] (request_wait_answer fs/fuse/dev.c:585 [inline]) [<81aeb534>] (schedule) from [<807692c0>] (__fuse_request_send fs/fuse/dev.c:599 [inline]) [<81aeb534>] (schedule) from [<807692c0>] (__fuse_simple_request+0x398/0x4f4 fs/fuse/dev.c:693) r5:dfaf5e50 r4:84e38230 [<80768f28>] (__fuse_simple_request) from [<807749a0>] (fuse_simple_request fs/fuse/fuse_i.h:1263 [inline]) [<80768f28>] (__fuse_simple_request) from [<807749a0>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:494) r8:86317f00 r7:86654040 r6:854c6500 r5:858e1b80 r4:86bca6c0 [<80774828>] (fuse_flush) from [<8057008c>] (filp_flush+0x38/0x88 fs/open.c:1469) r8:854c6540 r7:854dfd40 r6:0000001e r5:854c6500 r4:86bca6c0 [<80570054>] (filp_flush) from [<805700f0>] (filp_close+0x14/0x28 fs/open.c:1482) r7:854dfd40 r6:0000001e r5:86bca6c0 r4:854c6500 [<805700dc>] (filp_close) from [<805a1970>] (__range_close fs/file.c:794 [inline]) [<805700dc>] (filp_close) from [<805a1970>] (__do_sys_close_range fs/file.c:855 [inline]) [<805700dc>] (filp_close) from [<805a1970>] (sys_close_range+0x18c/0x224 fs/file.c:819) r5:00000005 r4:854c6500 [<805a17e4>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfaf5fa8 to 0xdfaf5ff0) 5fa0: 00000000 00000000 00000003 0000001e 00000000 7eec8918 5fc0: 00000000 00000000 00000000 000001b4 001d30ee ffffffff 00000000 003462e4 5fe0: 7eec8840 7eec8830 00028034 00130300 r10:000001b4 r9:85103100 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) r7:60010093 r6:60010093 r5:822a8688 r4:00000000 [<80201af0>] (show_stack) from [<8021e410>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201af0>] (show_stack) from [<8021e410>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021e3b4>] (dump_stack_lvl) from [<8021e43c>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:00000000 r6:00010013 r5:00000000 r4:00000001 [<8021e424>] (dump_stack) from [<81ad3b7c>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:113) [<81ad3a2c>] (nmi_cpu_backtrace) from [<81ad3ccc>] (nmi_trigger_cpumask_backtrace+0x130/0x1d8 lib/nmi_backtrace.c:62) r7:00000000 r6:8280c550 r5:8281afb8 r4:ffffffff [<81ad3b9c>] (nmi_trigger_cpumask_backtrace) from [<8022f124>] (arch_trigger_cpumask_backtrace+0x18/0x1c arch/arm/kernel/smp.c:852) r9:82ac7834 r8:8280c6d8 r7:00032492 r6:8474d7c4 r5:82804d80 r4:00000048 [<8022f10c>] (arch_trigger_cpumask_backtrace) from [<81adb7bc>] (trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]) [<8022f10c>] (arch_trigger_cpumask_backtrace) from [<81adb7bc>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f10c>] (arch_trigger_cpumask_backtrace) from [<81adb7bc>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81adb754>] (sys_info) from [<80385270>] (check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]) [<81adb754>] (sys_info) from [<80385270>] (watchdog+0x59c/0x8d8 kernel/hung_task.c:515) r5:82804d80 r4:841e4e14 [<80384cd4>] (watchdog) from [<802814a4>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e60 r8:83103500 r7:00000000 r6:80384cd4 r5:831f8000 r4:8333dc00 [<80281388>] (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 r5:80281388 r4:8333dc00 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2900 Comm: klogd Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express PC is at prb_read kernel/printk/printk_ringbuffer.c:1979 [inline] PC is at _prb_read_valid+0x78/0x330 kernel/printk/printk_ringbuffer.c:2170 LR is at 0x84751880 pc : [<802e8400>] lr : [<84751880>] psr: 20030013 sp : ebee9da0 ip : 00000000 fp : ebee9e1c r10: ebee9de0 r9 : ebee9e20 r8 : 00000000 r7 : 8282753c r6 : 00000b5a r5 : 82a834e8 r4 : 0000000d r3 : ffffffff r2 : 00000020 r1 : 828d7580 r0 : 8282753c Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 84f921c0 DAC: 00000000 Call trace: [<802e8388>] (_prb_read_valid) from [<802e92d0>] (prb_read_valid+0x24/0x2c kernel/printk/printk_ringbuffer.c:2242) r10:82a83288 r9:0000006a r8:00000000 r7:76fb032c r6:00000213 r5:82a834e8 r4:000001ec [<802e92ac>] (prb_read_valid) from [<802e1e44>] (syslog_print+0x274/0x3b8 kernel/printk/printk.c:1628) [<802e1bd0>] (syslog_print) from [<802e24cc>] (do_syslog+0x14c/0x37c kernel/printk/printk.c:1763) r10:00000067 r9:84751880 r8:76fb0140 r7:000003ff r6:00000000 r5:00000000 r4:00000002 [<802e2380>] (do_syslog) from [<802e2710>] (__do_sys_syslog kernel/printk/printk.c:1855 [inline]) [<802e2380>] (do_syslog) from [<802e2710>] (sys_syslog+0x14/0x18 kernel/printk/printk.c:1853) r9:84751880 r8:8020029c r7:00000067 r6:00000000 r5:76fb0167 r4:76fb0140 [<802e26fc>] (sys_syslog) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xebee9fa8 to 0xebee9ff0) 9fa0: 76fb0140 76fb0167 00000002 76fb0140 000003ff 76fb0140 9fc0: 76fb0140 76fb0167 00000000 00000067 00000000 76faf904 76fb0554 76f8f3bc 9fe0: 76fafcdc 7eb4fc94 76f332c8 76e553ec