rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=9c6/1/0x4000000000000000 softirq=130065/130067 fqs=1 (t=10501 jiffies g=239757 q=117) rcu: rcu_preempt kthread starved for 10500 jiffies! g239757 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:29080 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_timeout+0x148/0x250 kernel/time/timer.c:1879 rcu_gp_fqs_loop kernel/rcu/tree.c:1923 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2097 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 NMI backtrace for cpu 0 CPU: 0 PID: 31708 Comm: syz-executor.4 Not tainted 5.9.0-rc1-next-20200821-syzkaller #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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:165 [inline] rcu_dump_cpu_stacks+0x194/0x1cf kernel/rcu/tree_stall.h:318 print_cpu_stall kernel/rcu/tree_stall.h:551 [inline] check_cpu_stall kernel/rcu/tree_stall.h:625 [inline] rcu_pending kernel/rcu/tree.c:3694 [inline] rcu_sched_clock_irq.cold+0x5b3/0xcc3 kernel/rcu/tree.c:2565 update_process_times+0x25/0xa0 kernel/time/timer.c:1710 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x1d1/0x2a0 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0x4c/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:write_comp_data+0x13/0x80 kernel/kcov.c:218 Code: 48 8b 80 20 14 00 00 c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 49 89 f2 65 8b 05 76 90 8d 7e 65 48 8b 34 25 c0 fe 01 00 00 01 ff 00 74 0f f6 c4 01 74 59 8b 86 2c 14 00 00 85 c0 74 4f RSP: 0018:ffffc900000077a0 EFLAGS: 00000246 RAX: 0000000000000101 RBX: 0000000000000001 RCX: ffffffff818045e8 RDX: 0000000000000001 RSI: ffff888027fc8100 RDI: 0000000000000001 RBP: 000000000045d579 R08: 0000000000000000 R09: ffffffff8c68d9e7 R10: 0000000000000000 R11: 0000000000000001 R12: ffffc90000007800 R13: 0000000000000000 R14: ffff888027fc8100 R15: 00000000000000e0 rcu_read_unlock include/linux/rcupdate.h:691 [inline] is_bpf_text_address+0xe8/0x160 kernel/bpf/core.c:706 kernel_text_address kernel/extable.c:151 [inline] kernel_text_address+0xbd/0xf0 kernel/extable.c:120 __kernel_text_address+0x9/0x30 kernel/extable.c:105 unwind_get_return_address arch/x86/kernel/unwind_orc.c:317 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:312 arch_stack_walk+0x97/0xf0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 slab_post_alloc_hook mm/slab.h:517 [inline] slab_alloc_node mm/slab.c:3254 [inline] kmem_cache_alloc_node+0x136/0x3f0 mm/slab.c:3574 __alloc_skb+0x71/0x550 net/core/skbuff.c:198 alloc_skb include/linux/skbuff.h:1085 [inline] mrp_pdu_init net/802/mrp.c:300 [inline] mrp_pdu_append_vecattr_event+0x7b4/0x1020 net/802/mrp.c:399 mrp_attr_event+0x173/0x220 net/802/mrp.c:494 mrp_mad_event net/802/mrp.c:574 [inline] mrp_join_timer+0x5a/0xc0 net/802/mrp.c:591 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413 expire_timers kernel/time/timer.c:1458 [inline] __run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755 __run_timers kernel/time/timer.c:1736 [inline] run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768 __do_softirq+0x2de/0xa24 kernel/softirq.c:298 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x1f3/0x230 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:__unwind_start+0x0/0x800 arch/x86/kernel/unwind_orc.c:629 Code: 20 4c 8b 44 24 18 e9 38 ef ff ff 4c 89 ff e8 f7 e4 80 00 e9 aa ee ff ff e8 fd e4 80 00 e9 9b f3 ff ff 0f 1f 84 00 00 00 00 00 <41> 57 49 89 ff 41 56 41 55 4d 8d 6f 28 41 54 49 89 d4 ba 60 00 00 RSP: 0018:ffffc90008707868 EFLAGS: 00000246 RAX: ffff888027fc8100 RBX: ffffffff81636110 RCX: ffffc900087078f8 RDX: 0000000000000000 RSI: ffff888027fc8100 RDI: ffffc90008707870 RBP: ffffc900087078f8 R08: ffffed1006571db7 R09: ffffed1006571dde R10: fffffbfff18d1b4d R11: ffffffff8c6dd6e8 R12: ffffc90008707928 R13: 0000000000000000 R14: ffff888027fc8100 R15: 0000000000000138 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0x5e/0xf0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 slab_post_alloc_hook mm/slab.h:517 [inline] slab_alloc mm/slab.c:3312 [inline] kmem_cache_alloc+0x138/0x3a0 mm/slab.c:3482 __d_alloc+0x2a/0x950 fs/dcache.c:1709 d_alloc_pseudo+0x19/0x70 fs/dcache.c:1838 alloc_file_pseudo+0xc6/0x250 fs/file_table.c:226 anon_inode_getfile fs/anon_inodes.c:91 [inline] anon_inode_getfile+0xc8/0x1f0 fs/anon_inodes.c:74 __do_sys_perf_event_open+0x117b/0x2cb0 kernel/events/core.c:11867 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d579 Code: 5d b4 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd812c0ec78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 0000000000024680 RCX: 000000000045d579 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180 RBP: 000000000118d0d0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000118d08c R13: 00007ffe578bc84f R14: 00007fd812c0f9c0 R15: 000000000118d08c