rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=0c1/1/0x4000000000000000 softirq=141052/141054 fqs=17 (t=10502 jiffies g=250781 q=517) rcu: rcu_preempt kthread starved for 10467 jiffies! g250781 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1358 Comm: aoe_tx0 Not tainted 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1169 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0x28/0x150 kernel/rcu/tree.c:1160 Code: 00 90 65 8b 15 29 1e a0 7e 81 e2 00 00 f0 00 b8 01 00 00 00 75 0a 8b 15 a2 75 0c 0c 85 d2 75 01 c3 55 53 65 ff 05 08 1e a0 7e 53 f6 d2 07 48 c7 c3 c0 28 03 00 83 f8 07 89 c5 0f 87 f5 00 00 RSP: 0018:ffffc90000007a90 EFLAGS: 00000082 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8161c404 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8880b9c32a08 RBP: 1ffff92000000f59 R08: 0000000000000000 R09: ffff8880b9c32a0b R10: ffffed1017386541 R11: 000000000000003f R12: 0000000000000001 R13: 000000000000000e R14: dead000000000100 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa10c6c1718 CR3: 0000000073fa9000 CR4: 00000000001526f0 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_held_common kernel/rcu/update.c:102 [inline] rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:123 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5636 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irqrestore+0x16/0x70 kernel/locking/spinlock.c:194 __debug_check_no_obj_freed lib/debugobjects.c:1002 [inline] debug_check_no_obj_freed+0x20c/0x420 lib/debugobjects.c:1023 slab_free_hook mm/slub.c:1675 [inline] slab_free_freelist_hook+0xde/0x190 mm/slub.c:1725 slab_free mm/slub.c:3483 [inline] kmem_cache_free+0x8a/0x5b0 mm/slub.c:3499 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:699 __kfree_skb net/core/skbuff.c:756 [inline] consume_skb net/core/skbuff.c:911 [inline] consume_skb+0xcf/0x160 net/core/skbuff.c:905 mac80211_hwsim_tx_frame+0x1f6/0x2a0 drivers/net/wireless/mac80211_hwsim.c:1785 mac80211_hwsim_beacon_tx+0x49b/0x930 drivers/net/wireless/mac80211_hwsim.c:1838 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0x70/0x180 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xd5/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1861 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 do_softirq.part.0+0xde/0x130 kernel/softirq.c:459 do_softirq kernel/softirq.c:451 [inline] __local_bh_enable_ip+0x102/0x120 kernel/softirq.c:383 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:757 [inline] __dev_queue_xmit+0x1b82/0x36e0 net/core/dev.c:4229 tx+0x68/0xb0 drivers/block/aoe/aoenet.c:63 kthread+0x1e7/0x3b0 drivers/block/aoe/aoecmd.c:1230 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 NMI backtrace for cpu 1 CPU: 1 PID: 302 Comm: syz-executor.4 Not tainted 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2599 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:rb_first+0x29/0x80 lib/rbtree.c:471 Code: 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 53 48 c1 ea 03 48 83 ec 08 80 3c 02 00 75 46 48 bb 00 00 00 00 00 fc ff df 48 8b 07 <48> 85 c0 75 05 eb 1d 48 89 d0 48 8d 78 10 48 89 fa 48 c1 ea 03 80 RSP: 0018:ffffc90000dc0cf0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff815bd200 RDX: 1ffff1100ea334a0 RSI: 0000000000000004 RDI: ffff88807519a500 RBP: ffffc90000dc0d70 R08: 0000000000000001 R09: 0000000000000003 R10: fffff520001b8193 R11: 0000000000000000 R12: ffff88807519a400 R13: ffff88807519a460 R14: ffffffff873b3180 R15: 0000000000000000 garp_gid_event net/802/garp.c:398 [inline] garp_join_timer+0x2c/0xf0 net/802/garp.c:419 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:schedule_debug kernel/sched/core.c:5493 [inline] RIP: 0010:__schedule+0x131/0x26f0 kernel/sched/core.c:6178 Code: ef 1e 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 75 20 4c 89 f2 48 c1 ea 03 80 3c 02 00 0f 85 1a 1f 00 00 49 81 3e 9d 6e ac 57 <0f> 85 9c 25 00 00 44 8b 8d 70 ff ff ff 49 8d 45 18 48 89 85 60 ff RSP: 0018:ffffc900037e7508 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000031a40 RCX: 1ffff920006fcea9 RDX: 1ffff920006fc000 RSI: 0000000000000001 RDI: ffff8880243f3920 RBP: ffffc900037e75d0 R08: 0000000000000000 R09: ffff88801115c543 R10: ffffed100222b8a8 R11: 0000000000000028 R12: ffff8880b9d31a40 R13: ffff8880243f3900 R14: ffffc900037e0000 R15: ffffea0002404c08 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6459 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:403 [inline] __set_page_dirty_buffers+0x2df/0x5d0 fs/buffer.c:640 set_page_dirty+0x285/0x6b0 mm/page-writeback.c:2609 fault_dirty_shared_page+0xc7/0x400 mm/memory.c:2900 do_shared_fault mm/memory.c:4252 [inline] do_fault mm/memory.c:4304 [inline] handle_pte_fault mm/memory.c:4558 [inline] __handle_mm_fault+0x26b4/0x5320 mm/memory.c:4693 handle_mm_fault+0x1c8/0x790 mm/memory.c:4791 faultin_page mm/gup.c:937 [inline] __get_user_pages+0x503/0xf80 mm/gup.c:1158 __get_user_pages_locked mm/gup.c:1343 [inline] __get_user_pages_remote+0x18f/0x840 mm/gup.c:1852 pin_user_pages_remote+0x63/0x90 mm/gup.c:2927 process_vm_rw_single_vec mm/process_vm_access.c:105 [inline] process_vm_rw_core.constprop.0+0x445/0x990 mm/process_vm_access.c:215 process_vm_rw+0x29c/0x300 mm/process_vm_access.c:283 __do_sys_process_vm_writev mm/process_vm_access.c:303 [inline] __se_sys_process_vm_writev mm/process_vm_access.c:298 [inline] __x64_sys_process_vm_writev+0xdf/0x1b0 mm/process_vm_access.c:298 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7facc4e03739 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007facc237a188 EFLAGS: 00000246 ORIG_RAX: 0000000000000137 RAX: ffffffffffffffda RBX: 00007facc4f07f80 RCX: 00007facc4e03739 RDX: 0000000000000002 RSI: 0000000020c22000 RDI: 000000000000196c RBP: 00007facc4e5dcc4 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000020c22fa0 R11: 0000000000000246 R12: 00007facc4f07f80 R13: 00007facc543bb1f R14: 00007facc237a300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 90 nop 1: 65 8b 15 29 1e a0 7e mov %gs:0x7ea01e29(%rip),%edx # 0x7ea01e31 8: 81 e2 00 00 f0 00 and $0xf00000,%edx e: b8 01 00 00 00 mov $0x1,%eax 13: 75 0a jne 0x1f 15: 8b 15 a2 75 0c 0c mov 0xc0c75a2(%rip),%edx # 0xc0c75bd 1b: 85 d2 test %edx,%edx 1d: 75 01 jne 0x20 1f: c3 retq 20: 55 push %rbp 21: 53 push %rbx 22: 65 ff 05 08 1e a0 7e incl %gs:0x7ea01e08(%rip) # 0x7ea01e31 * 29: e8 53 f6 d2 07 callq 0x7d2f681 <-- trapping instruction 2e: 48 c7 c3 c0 28 03 00 mov $0x328c0,%rbx 35: 83 f8 07 cmp $0x7,%eax 38: 89 c5 mov %eax,%ebp 3a: 0f .byte 0xf 3b: 87 f5 xchg %esi,%ebp