INFO: task syz.1.10931:11602 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.1.10931 state:D stack:0 pid:11602 tgid:11602 ppid:7517 task_flags:0x400040 flags:0x00000005 Call trace: [<81b1de5c>] (__schedule) from [<81b1f2f0>] (__schedule_loop kernel/sched/core.c:7268 [inline]) [<81b1de5c>] (__schedule) from [<81b1f2f0>] (schedule+0x2c/0x134 kernel/sched/core.c:7283) r10:86102600 r9:84810c80 r8:863d9000 r7:84f96ad8 r6:ec3d1ea8 r5:ec3d1e50 r4:84810c80 [<81b1f2c4>] (schedule) from [<80783c48>] (request_wait_answer fs/fuse/dev.c:590 [inline]) [<81b1f2c4>] (schedule) from [<80783c48>] (__fuse_request_send fs/fuse/dev.c:604 [inline]) [<81b1f2c4>] (schedule) from [<80783c48>] (__fuse_simple_request+0x3b8/0x520 fs/fuse/dev.c:699) r5:ec3d1e50 r4:84f96a80 [<80783890>] (__fuse_simple_request) from [<8078d1bc>] (fuse_simple_request fs/fuse/fuse_i.h:1262 [inline]) [<80783890>] (__fuse_simple_request) from [<8078d1bc>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:500) r8:86085f00 r7:86071e40 r6:83101b00 r5:850b0b40 r4:86102600 [<8078d044>] (fuse_flush) from [<80580ca0>] (filp_flush+0x38/0x88 fs/open.c:1467) r8:83101b40 r7:860b7480 r6:0000001e r5:83101b00 r4:86102600 [<80580c68>] (filp_flush) from [<80580d04>] (filp_close+0x14/0x28 fs/open.c:1480) r7:860b7480 r6:0000001e r5:86102600 r4:83101b00 [<80580cf0>] (filp_close) from [<805b300c>] (__range_close fs/file.c:794 [inline]) [<80580cf0>] (filp_close) from [<805b300c>] (__do_sys_close_range fs/file.c:855 [inline]) [<80580cf0>] (filp_close) from [<805b300c>] (sys_close_range+0x18c/0x224 fs/file.c:819) r5:00000007 r4:83101b00 [<805b2e80>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xec3d1fa8 to 0xec3d1ff0) 1fa0: 00000000 00000000 00000003 0000001e 00000000 7e9f6918 1fc0: 00000000 00000000 00000000 000001b4 005a4962 ffffffff 00000000 003462e4 1fe0: 7e9f6840 7e9f6830 0002853c 00130810 r10:000001b4 r9:84810c80 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) r7:60000093 r6:60000093 r5:8231e0c8 r4:00000000 [<80201af0>] (show_stack) from [<8021e37c>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201af0>] (show_stack) from [<8021e37c>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021e320>] (dump_stack_lvl) from [<8021e3a8>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:00000000 r6:00000013 r5:00000000 r4:00000001 [<8021e390>] (dump_stack) from [<81b07734>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:113) [<81b075e4>] (nmi_cpu_backtrace) from [<81b07884>] (nmi_trigger_cpumask_backtrace+0x130/0x1d8 lib/nmi_backtrace.c:62) r7:00000000 r6:82a0b550 r5:82a1a2b8 r4:ffffffff [<81b07754>] (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 r5:00007f27 r4:00000048 [<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0f3d0>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0f3d0>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0f3d0>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b0f368>] (sys_info) from [<8038ac98>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b0f368>] (sys_info) from [<8038ac98>] (watchdog+0x3ac/0x858 kernel/hung_task.c:561) r5:00007f27 r4:00000001 [<8038a8ec>] (watchdog) from [<80281540>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e58 r8:83357b80 r7:00000000 r6:8038a8ec r5:83811900 r4:83305040 [<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 r4:83305040 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2913 Comm: klogd Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express PC is at mmiocpy+0x58/0x330 arch/arm/lib/copy_template.S:109 LR is at 0x7830206f pc : [<81ae93f8>] lr : [<7830206f>] psr: a0030113 sp : ebcf1d84 ip : 74203861 fp : ebcf1e1c r10: ebcf1de0 r9 : 66316433 r8 : 63657830 r7 : 82a263e8 r6 : 286b6361 r5 : 7473206e r4 : 6f697470 r3 : 65637845 r2 : ffffff89 r1 : 82cb9dec r0 : 8692f820 Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 84ff1d40 DAC: 00000000 Call trace: [<802ea540>] (_prb_read_valid) from [<802eb488>] (prb_read_valid+0x24/0x2c kernel/printk/printk_ringbuffer.c:2245) r10:82c7e430 r9:00000067 r8:00000000 r7:76f2833d r6:00000202 r5:82c7e6b0 r4:000001fd [<802eb464>] (prb_read_valid) from [<802e400c>] (syslog_print+0x274/0x3b8 kernel/printk/printk.c:1628) [<802e3d98>] (syslog_print) from [<802e4694>] (do_syslog+0x14c/0x37c kernel/printk/printk.c:1763) r10:00000067 r9:8480b200 r8:76f28140 r7:000003ff r6:00000000 r5:00000000 r4:00000002 [<802e4548>] (do_syslog) from [<802e48d8>] (__do_sys_syslog kernel/printk/printk.c:1855 [inline]) [<802e4548>] (do_syslog) from [<802e48d8>] (sys_syslog+0x14/0x18 kernel/printk/printk.c:1853) r9:8480b200 r8:8020029c r7:00000067 r6:00000000 r5:76f28320 r4:76f28140 [<802e48c4>] (sys_syslog) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xebcf1fa8 to 0xebcf1ff0) 1fa0: 76f28140 76f28320 00000002 76f28140 000003ff 76f28140 1fc0: 76f28140 76f28320 00000000 00000067 00000000 76f27904 76f28554 76f073bc 1fe0: 76f27cdc 7ee90c94 76eab2c8 76dcd3ec