rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=632/1/0x4000000000000004 softirq=227377/227377 fqs=8 (t=10502 jiffies g=246785 q=598) rcu: rcu_preempt kthread starved for 10487 jiffies! g246785 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 28896 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3254 [inline] __schedule+0x877/0xc50 kernel/sched/core.c:3880 schedule+0x131/0x1e0 kernel/sched/core.c:3947 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1807 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline] rcu_gp_kthread+0xef8/0x1790 kernel/rcu/tree.c:1768 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 0 CPU: 0 PID: 19281 Comm: syz-executor.1 Not tainted 5.3.0-rc8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2736 [inline] rcu_sched_clock_irq+0xb95/0x16d0 kernel/rcu/tree.c:2183 update_process_times+0x134/0x190 kernel/time/timer.c:1639 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1296 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x403/0x850 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1106 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1131 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:pie_timer+0x1/0x7d0 net/sched/sch_pie.c:444 Code: 80 e1 07 80 c1 03 38 c1 0f 8c 56 fe ff ff 4c 89 ff e8 63 c5 9f fb e9 49 fe ff ff e8 49 ac 39 fb 66 0f 1f 84 00 00 00 00 00 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 68 49 89 fe 49 bc 00 RSP: 0018:ffff8880aea09d50 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: ffffffff8163bc64 RBX: ffff8880aea24a80 RCX: ffff88820d042300 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff88801c95f9c0 RBP: ffff8880aea09db0 R08: ffffffff8163bc5b R09: fffffbfff117be8d R10: fffffbfff117be8d R11: 0000000000000000 R12: 000000010001b5a6 R13: 0000000000000100 R14: ffffffff860cc380 R15: ffff88801c95f9c0 expire_timers kernel/time/timer.c:1366 [inline] __run_timers+0x79e/0x970 kernel/time/timer.c:1685 run_timer_softirq+0x4a/0x90 kernel/time/timer.c:1698 __do_softirq+0x333/0x7c4 arch/x86/include/asm/paravirt.h:778 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x227/0x230 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:537 [inline] smp_apic_timer_interrupt+0x113/0x280 arch/x86/kernel/apic/apic.c:1133 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:preempt_count_add+0x8/0x160 kernel/sched/core.c:3602 Code: 07 80 c1 03 38 c1 0f 8c 3b ff ff ff 4c 89 e7 e8 4e 06 5c 00 e9 2e ff ff ff 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 <53> 89 fb 65 01 3d ca 7b b1 7e 48 c7 c0 40 1d 9c 89 48 c1 e8 03 49 RSP: 0018:ffff888202c37600 EFLAGS: 00000297 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000002 RDX: ffffc90008162000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff888202c37610 R08: ffffffff81abe20c R09: ffffed103232c600 R10: fffff94000c8cb1f R11: 0000000000000000 R12: 0000000000000201 R13: ffffea00064658c0 R14: 0005088000000000 R15: 0000000000000001 kmap_atomic include/linux/highmem.h:93 [inline] clear_highpage include/linux/highmem.h:213 [inline] kernel_init_free_pages mm/page_alloc.c:1124 [inline] prep_new_page+0x1aa/0x2e0 mm/page_alloc.c:2156 get_page_from_freelist+0x7f0/0xa40 mm/page_alloc.c:3680 __alloc_pages_nodemask+0x264/0x5d0 mm/page_alloc.c:4714 alloc_pages_current+0x2db/0x500 mm/mempolicy.c:2153 alloc_pages include/linux/gfp.h:509 [inline] __vmalloc_area_node mm/vmalloc.c:2424 [inline] __vmalloc_node_range+0x41f/0x890 mm/vmalloc.c:2488 __vmalloc_node mm/vmalloc.c:2543 [inline] __vmalloc+0x45/0x50 mm/vmalloc.c:2549 _snd_pcm_lib_alloc_vmalloc_buffer+0x126/0x1c0 sound/core/pcm_memory.c:370 snd_pcm_lib_alloc_vmalloc_buffer include/sound/pcm.h:1204 [inline] loopback_hw_params+0x40/0x60 sound/drivers/aloop.c:579 snd_pcm_hw_params+0x2fc/0x1390 sound/core/pcm_native.c:665 snd_pcm_kernel_ioctl+0x116/0x12e0 sound/core/pcm_native.c:3023 snd_pcm_oss_change_params_locked+0x2413/0x4260 sound/core/oss/pcm_oss.c:944 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1087 [inline] snd_pcm_oss_make_ready+0x122/0x2e0 sound/core/oss/pcm_oss.c:1146 snd_pcm_oss_sync+0x1b2/0x900 sound/core/oss/pcm_oss.c:1707 snd_pcm_oss_release+0x134/0x2b0 sound/core/oss/pcm_oss.c:2545 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x17e/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:163 [inline] prepare_exit_to_usermode+0x459/0x580 arch/x86/entry/common.c:194 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274 do_syscall_64+0x126/0x140 arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4598e9 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7e02321c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000124 RAX: 0000000000000004 RBX: 0000000000000003 RCX: 00000000004598e9 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7e023226d4 R13: 00000000004bff3a R14: 00000000004d1ec0 R15: 00000000ffffffff