INFO: task syz.3.44971:1551 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.3.44971 state:D stack:0 pid:1551 tgid:1551 ppid:28936 task_flags:0x400040 flags:0x00000005 Call trace: [<81b5f4fc>] (__schedule) from [<81b60994>] (__schedule_loop kernel/sched/core.c:7311 [inline]) [<81b5f4fc>] (__schedule) from [<81b60994>] (schedule+0x2c/0xec kernel/sched/core.c:7326) r10:854ed900 r9:83318c40 r8:8578de00 r7:852a5c98 r6:dfbe1ea0 r5:dfbe1e30 r4:83318c40 [<81b60968>] (schedule) from [<807a0348>] (request_wait_answer fs/fuse/dev.c:743 [inline]) [<81b60968>] (schedule) from [<807a0348>] (__fuse_request_send fs/fuse/dev.c:757 [inline]) [<81b60968>] (schedule) from [<807a0348>] (fuse_chan_send+0x390/0x47c fs/fuse/dev.c:833) r5:dfbe1e30 r4:852a5c40 [<8079ffb8>] (fuse_chan_send) from [<807b28a0>] (__fuse_simple_request+0x5c/0x68 fs/fuse/req.c:69) r8:8601bd00 r7:860c1180 r6:8fd13200 r5:912d0780 r4:dfbe1ea0 [<807b2844>] (__fuse_simple_request) from [<807a803c>] (fuse_simple_request fs/fuse/fuse_i.h:1012 [inline]) [<807b2844>] (__fuse_simple_request) from [<807a803c>] (fuse_flush+0x178/0x1b4 fs/fuse/file.c:504) r5:85858240 r4:854ed900 [<807a7ec4>] (fuse_flush) from [<80599b24>] (filp_flush+0x38/0x88 fs/open.c:1471) r8:8fd13240 r7:84744900 r6:0000001e r5:8fd13200 r4:854ed900 [<80599aec>] (filp_flush) from [<80599b88>] (filp_close+0x14/0x28 fs/open.c:1484) r7:84744900 r6:0000001e r5:854ed900 r4:8fd13200 [<80599b74>] (filp_close) from [<805cc1b0>] (__range_close fs/file.c:793 [inline]) [<80599b74>] (filp_close) from [<805cc1b0>] (__do_sys_close_range fs/file.c:854 [inline]) [<80599b74>] (filp_close) from [<805cc1b0>] (sys_close_range+0x18c/0x224 fs/file.c:818) r5:00000004 r4:8fd13200 [<805cc024>] (sys_close_range) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67) Exception stack(0xdfbe1fa8 to 0xdfbe1ff0) 1fa0: 00000000 00000000 00000003 0000001e 00000000 7ef60920 1fc0: 00000000 00000000 00000000 000001b4 00784ab1 ffffffff 00000000 003562e4 1fe0: 7ef60848 7ef60838 00028604 001309e0 r10:000001b4 r9:83318c40 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) r7:60000093 r6:60000093 r5:8233309c r4:00000000 [<80201a74>] (show_stack) from [<8021e5fc>] (__dump_stack lib/dump_stack.c:94 [inline]) [<80201a74>] (show_stack) from [<8021e5fc>] (dump_stack_lvl+0x5c/0x70 lib/dump_stack.c:120) [<8021e5a0>] (dump_stack_lvl) from [<8021e628>] (dump_stack+0x18/0x1c lib/dump_stack.c:129) r7:00000000 r6:00000013 r5:00000001 r4:00000001 [<8021e610>] (dump_stack) from [<81b48b9c>] (nmi_cpu_backtrace+0x150/0x170 lib/nmi_backtrace.c:122) [<81b48a4c>] (nmi_cpu_backtrace) from [<81b48cf0>] (nmi_trigger_cpumask_backtrace+0x134/0x208 lib/nmi_backtrace.c:65) r7:82a0b150 r6:83320c40 r5:82a1c7b8 r4:ffffffff [<81b48bbc>] (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 r5:00007f0f r4:00000048 [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b5082c>] (trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b5082c>] (__sys_info lib/sys_info.c:157 [inline]) [<8022f0dc>] (arch_trigger_cpumask_backtrace) from [<81b5082c>] (sys_info+0x68/0xa8 lib/sys_info.c:165) [<81b507c4>] (sys_info) from [<8038f988>] (check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]) [<81b507c4>] (sys_info) from [<8038f988>] (watchdog+0x3a0/0x848 kernel/hung_task.c:561) r5:00007f0f r4:0000000a [<8038f5e8>] (watchdog) from [<80281710>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df819e60 r8:831d4600 r7:00000000 r6:8038f5e8 r5:83320c40 r4:833dd400 [<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 r4:833dd400 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2820 Comm: pr/ttyAMA-1 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: ARM-Versatile Express PC is at bpf_net_ctx_get_all_used_flush_lists include/linux/filter.h:904 [inline] PC is at xdp_do_check_flushed+0x30/0x214 net/core/filter.c:4452 LR is at __napi_poll+0x44/0x268 net/core/dev.c:7738 pc : [<8169859c>] lr : [<81660788>] psr: 60000113 sp : df801e18 ip : 00000000 fp : df801e3c r10: df801e98 r9 : 00000000 r8 : 828cb740 r7 : 00000040 r6 : df801e93 r5 : 83976008 r4 : 83976008 r3 : df801ea8 r2 : 00000000 r1 : 00000000 r0 : 83976008 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 906047c0 DAC: fffffffd Call trace: frame pointer underflow [<8169856c>] (xdp_do_check_flushed) from [<81660788>] (__napi_poll+0x44/0x268 net/core/dev.c:7738) r6:df801e93 r5:83976008 r4:00000001 [<81660744>] (__napi_poll) from [<81660d08>] (napi_poll net/core/dev.c:7798 [inline]) [<81660744>] (__napi_poll) from [<81660d08>] (net_rx_action+0x35c/0x3e8 net/core/dev.c:7955) r9:00000000 r8:0000012c r7:83976008 r6:8397600c r5:dddd2480 r4:ffffffff [<816609ac>] (net_rx_action) from [<8025a0dc>] (handle_softirqs+0x160/0x4e4 kernel/softirq.c:622) r10:84911880 r9:00000008 r8:00000101 r7:0000000c r6:00000004 r5:00000003 r4:82a0308c [<80259f7c>] (handle_softirqs) from [<8025a5fc>] (__do_softirq kernel/softirq.c:656 [inline]) [<80259f7c>] (handle_softirqs) from [<8025a5fc>] (invoke_softirq kernel/softirq.c:496 [inline]) [<80259f7c>] (handle_softirqs) from [<8025a5fc>] (__irq_exit_rcu+0x150/0x1d0 kernel/softirq.c:735) r10:82b5cd1c r9:84911880 r8:00000000 r7:eb43de78 r6:824e6bd8 r5:82522088 r4:84911880 [<8025a4ac>] (__irq_exit_rcu) from [<8025a934>] (irq_exit+0x10/0x18 kernel/softirq.c:764) r5:82522088 r4:828d3e6c [<8025a924>] (irq_exit) from [<81b5bbdc>] (generic_handle_arch_irq+0x7c/0x80 kernel/irq/handle.c:293) [<81b5bb60>] (generic_handle_arch_irq) from [<81b28874>] (call_with_stack+0x1c/0x20 arch/arm/lib/call_with_stack.S:40) r9:84911880 r8:00000000 r7:eb43deac r6:ffffffff r5:60000013 r4:81b69e5c [<81b28858>] (call_with_stack) from [<80200bec>] (__irq_svc+0x8c/0xbc arch/arm/kernel/entry-armv.S:228) Exception stack(0xeb43de78 to 0xeb43dec0) de60: 850e3040 60000013 de80: 00000000 0000128a 00000001 00000000 82b5cc80 00000117 00000000 00000000 dea0: 82b5cd1c eb43ded4 eb43ded8 eb43dec8 80b02740 81b69e5c 60000013 ffffffff [<81b69e34>] (_raw_spin_unlock_irqrestore) from [<80b02740>] (spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]) [<81b69e34>] (_raw_spin_unlock_irqrestore) from [<80b02740>] (__uart_port_unlock_irqrestore include/linux/serial_core.h:618 [inline]) [<81b69e34>] (_raw_spin_unlock_irqrestore) from [<80b02740>] (pl011_console_device_unlock+0x20/0x24 drivers/tty/serial/amba-pl011.c:2700) [<80b02720>] (pl011_console_device_unlock) from [<802ec210>] (nbcon_emit_one+0x88/0x100 kernel/printk/nbcon.c:1165) [<802ec188>] (nbcon_emit_one) from [<802ec490>] (nbcon_kthread_func+0x208/0x2ec kernel/printk/nbcon.c:1271) r6:82cc72ec r5:82b5cc80 r4:84911880 [<802ec288>] (nbcon_kthread_func) from [<80281710>] (kthread+0x11c/0x154 kernel/kthread.c:436) r10:00000000 r9:df941b38 r8:84d98100 r7:82b5cc80 r6:802ec288 r5:84911880 r4:8476ef40 [<802815f4>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137) Exception stack(0xeb43dfb0 to 0xeb43dff8) dfa0: 00000000 00000000 00000000 00000000 dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:802815f4 r4:8476ef40