INFO: task syz.7.38701:20422 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.7.38701 state:D stack:0 pid:20422 tgid:20422 ppid:13436 task_flags:0x400040 flags:0x00000005 Call trace: [<81b1dc1c>] (__schedule) from [<81b1f0b0>] (__schedule_loop kernel/sched/core.c:7268 [inline]) [<81b1dc1c>] (__schedule) from [<81b1f0b0>] (schedule+0x2c/0x134 kernel/sched/core.c:7283) r10:8559c400 r9:864c8c80 r8:871b3600 r7:84fc5bb8 r6:eb239ea8 r5:eb239e50 r4:864c8c80 [<81b1f084>] (schedule) from [<80783c54>] (request_wait_answer fs/fuse/dev.c:590 [inline]) [<81b1f084>] (schedule) from [<80783c54>] (__fuse_request_send fs/fuse/dev.c:604 [inline]) [<81b1f084>] (schedule) from [<80783c54>] (__fuse_simple_request+0x3b8/0x520 fs/fuse/dev.c:699) r5:eb239e50 r4:84fc5b60 [<8078389c>] (__fuse_simple_request) from [<8078d1c8>] (fuse_simple_request fs/fuse/fuse_i.h:1262 [inline]) [<8078389c>] (__fuse_simple_request) from [<8078d1c8>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:500) r8:830c5a80 r7:894f6a00 r6:868c6c00 r5:835ad8c0 r4:8559c400 [<8078d050>] (fuse_flush) from [<80580d00>] (filp_flush+0x38/0x88 fs/open.c:1467) r8:868c6c40 r7:8629ad40 r6:0000001e r5:868c6c00 r4:8559c400 [<80580cc8>] (filp_flush) from [<80580d64>] (filp_close+0x14/0x28 fs/open.c:1480) r7:8629ad40 r6:0000001e r5:8559c400 r4:868c6c00 [<80580d50>] (filp_close) from [<805b306c>] (__range_close fs/file.c:794 [inline]) [<80580d50>] (filp_close) from [<805b306c>] (__do_sys_close_range fs/file.c:855 [inline]) [<80580d50>] (filp_close) from [<805b306c>] (sys_close_range+0x18c/0x224 fs/file.c:819) r5:00000004 r4:868c6c00 [<805b2ee0>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xeb239fa8 to 0xeb239ff0) 9fa0: 00000000 00000000 00000003 0000001e 00000000 7eefb918 9fc0: 00000000 00000000 00000000 000001b4 009c0631 ffffffff 00000000 003462e4 9fe0: 7eefb840 7eefb830 0002853c 00130810 r10:000001b4 r9:864c8c80 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: [<80201a14>] (dump_backtrace) from [<80201b08>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257) r7:60000193 r6:60000193 r5:8231e058 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 r6:00000113 r5:00000001 r4:00000001 [<8021e390>] (dump_stack) from [<81b074f4>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:113) [<81b073a4>] (nmi_cpu_backtrace) from [<81b07644>] (nmi_trigger_cpumask_backtrace+0x130/0x1d8 lib/nmi_backtrace.c:62) r7:00000001 r6:82a0b550 r5:82a1a2b8 r4:ffffffff [<81b07514>] (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 r5:00007f0e r4:00000048 [<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0f190>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0f190>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f0ec>] (arch_trigger_cpumask_backtrace) from [<81b0f190>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b0f128>] (sys_info) from [<8038acc4>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b0f128>] (sys_info) from [<8038acc4>] (watchdog+0x3ac/0x858 kernel/hung_task.c:561) r5:00007f0e r4:00000001 [<8038a918>] (watchdog) from [<80281540>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e58 r8:83355880 r7:00000000 r6:8038a918 r5:833e9900 r4:831f7400 [<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 r4:831f7400 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3098 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express PC is at copy_page_from_iter+0x0/0x144 lib/iov_iter.c:425 LR is at anon_pipe_write+0x248/0x648 fs/pipe.c:522 pc : [<8090b37c>] lr : [<80593384>] psr: a0000013 sp : df9a1e70 ip : 00000000 fp : df9a1ed4 r10: 838ad980 r9 : 8416e400 r8 : df9a1f08 r7 : 00000000 r6 : deb4de08 r5 : 00000000 r4 : 830c6d00 r3 : df9a1ef0 r2 : 00001000 r1 : 00000000 r0 : deb4de08 Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 85596200 DAC: fffffffd Call trace: [<8059313c>] (anon_pipe_write) from [<805871cc>] (new_sync_write fs/read_write.c:595 [inline]) [<8059313c>] (anon_pipe_write) from [<805871cc>] (vfs_write fs/read_write.c:688 [inline]) [<8059313c>] (anon_pipe_write) from [<805871cc>] (vfs_write+0x3b8/0x450 fs/read_write.c:668) r10:81c22990 r9:8416e400 r8:8059313c r7:00000000 r6:7e9825d4 r5:838ad980 r4:0000001c [<80586e14>] (vfs_write) from [<80587430>] (ksys_write+0xcc/0xec fs/read_write.c:740) r10:00000004 r9:8416e400 r8:8020029c r7:0000001c r6:7e9825d4 r5:838ad980 r4:838ad980 [<80587364>] (ksys_write) from [<80587460>] (__do_sys_write fs/read_write.c:751 [inline]) [<80587364>] (ksys_write) from [<80587460>] (sys_write+0x10/0x14 fs/read_write.c:748) r7:00000004 r6:0000001c r5:00000000 r4:00000000 [<80587450>] (sys_write) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdf9a1fa8 to 0xdf9a1ff0) 1fa0: 00000000 00000000 00000002 7e9825d4 0000001c 00000000 1fc0: 00000000 00000000 0000001c 00000004 0000001c 00310000 00000000 7e982770 1fe0: 00000001 7e9824d8 0010b9d4 0010ba64