rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10462 ticks this GP) idle=3e1/1/0x4000000000000000 softirq=163778/163784 fqs=0 (t=10501 jiffies g=251497 q=28) rcu: rcu_preempt kthread starved for 10502 jiffies! g251497 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:28736 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: 23441 Comm: syz-executor.5 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:native_apic_mem_write+0x8/0x10 arch/x86/include/asm/apic.h:110 Code: c7 40 f7 ee 8e e8 28 3b 8a 00 eb b0 66 0f 1f 44 00 00 be 01 00 00 00 e9 e6 1e 2d 00 cc cc cc cc cc cc 89 ff 89 b7 00 c0 5f ff 0f 1f 80 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 53 89 fb 48 RSP: 0018:ffffc90000007fd0 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff8b337a60 RCX: 1ffff11017383f0c RDX: 1ffffffff1666f4c RSI: 0000000000000000 RDI: 00000000000000b0 RBP: 0000000000000000 R08: ffffffff8eefa018 R09: ffffffff8eefa00f R10: ffffffff8eefa017 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f99e6120700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ed95088458 CR3: 000000006a2b8000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: apic_eoi arch/x86/include/asm/apic.h:399 [inline] ack_APIC_irq arch/x86/include/asm/apic.h:445 [inline] __sysvec_apic_timer_interrupt+0x79/0x530 arch/x86/kernel/apic/apic.c:1101 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x3ba/0xb40 kernel/locking/qspinlock.c:508 Code: eb c6 45 01 01 41 bc 00 80 00 00 48 c1 e9 03 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c f3 90 <41> 83 ec 01 0f 84 72 04 00 00 41 0f b6 45 00 38 d8 7f 08 84 c0 0f RSP: 0018:ffffc9000385f568 EFLAGS: 00000206 RAX: 0000000000000003 RBX: 0000000000000000 RCX: 1ffffffff1769a0c RDX: 0000000000000001 RSI: ffffffff817c49b1 RDI: ffffffff81334591 RBP: ffffffff8bb4d060 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff817c4979 R11: 0000000000000000 R12: 0000000000004a2a R13: fffffbfff1769a0c R14: 0000000000000001 R15: ffff8880b9c327c0 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:363 [inline] sysctl_head_grab+0x20/0xb0 fs/proc/proc_sysctl.c:306 grab_header fs/proc/proc_sysctl.c:492 [inline] proc_sys_poll+0x7c/0x440 fs/proc/proc_sysctl.c:635 vfs_poll include/linux/poll.h:90 [inline] do_select+0x8cb/0x16a0 fs/select.c:534 core_sys_select+0x3c2/0x9c0 fs/select.c:677 do_pselect.constprop.0+0x17b/0x1c0 fs/select.c:759 __do_sys_pselect6 fs/select.c:800 [inline] __se_sys_pselect6 fs/select.c:791 [inline] __x64_sys_pselect6+0x1c5/0x2b0 fs/select.c:791 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: 0033:0x4665f9 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:00007f99e6120188 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000040 RBP: 00000000004bfcc4 R08: 0000000020000200 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffd09146c9f R14: 00007f99e6120300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 23446 Comm: syz-executor.0 Not tainted 5.14.0-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:105 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:mac80211_hwsim_tx_frame_no_nl.isra.0+0xa37/0x1330 drivers/net/wireless/mac80211_hwsim.c:1537 Code: 7f 04 41 8b 55 04 48 89 f8 48 c1 e8 03 0f b6 0c 28 48 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 b3 07 00 00 45 8b 7f 04 <89> d7 89 54 24 08 44 89 fe e8 2b b3 3f fc 8b 54 24 08 44 39 fa 74 RSP: 0018:ffffc90000dc0ba0 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffff88801d3eb2a0 RCX: 0000000000000000 RDX: 000000000000096c RSI: ffffffff853675e6 RDI: ffff88801d3eb4d4 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff85367445 R10: ffffffff85367503 R11: 0000000000000000 R12: ffff88803f5ef140 R13: ffff888021d734d0 R14: ffff888021d732a0 R15: 000000000000096c mac80211_hwsim_tx_frame+0x1ee/0x2a0 drivers/net/wireless/mac80211_hwsim.c:1784 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 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:spin_unlock include/linux/spinlock.h:403 [inline] RIP: 0010:sysctl_head_finish fs/proc/proc_sysctl.c:319 [inline] RIP: 0010:sysctl_head_finish fs/proc/proc_sysctl.c:313 [inline] RIP: 0010:proc_sys_poll+0x2cc/0x440 fs/proc/proc_sysctl.c:659 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 4f 01 00 00 48 8b 6b 18 48 85 ed 0f 85 be 00 00 00 e8 8b 27 83 ff 48 c7 c7 60 d0 b4 8b ff 79 44 07 e8 7a 27 83 ff 44 89 e0 48 83 c4 20 5b 5d 41 5c 41 RSP: 0018:ffffc900031df6e8 EFLAGS: 00000212 RAX: 0000000000025d52 RBX: ffff88807c5b8000 RCX: ffffc900017c1000 RDX: 0000000000040000 RSI: ffffffff81f2f9b5 RDI: ffffffff8bb4d060 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000003 R10: ffffffff81f2f97b R11: 0000000000000000 R12: 0000000000000145 R13: ffffc900031df898 R14: 0000000000000000 R15: ffff88807900d7a8 vfs_poll include/linux/poll.h:90 [inline] do_select+0x8cb/0x16a0 fs/select.c:534 core_sys_select+0x3c2/0x9c0 fs/select.c:677 do_pselect.constprop.0+0x17b/0x1c0 fs/select.c:759 __do_sys_pselect6 fs/select.c:800 [inline] __se_sys_pselect6 fs/select.c:791 [inline] __x64_sys_pselect6+0x1c5/0x2b0 fs/select.c:791 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: 0033:0x4665f9 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:00007f755c0c0188 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000040 RBP: 00000000004bfcc4 R08: 0000000020000200 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffd1b8a707f R14: 00007f755c0c0300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: c7 40 f7 ee 8e e8 28 movl $0x28e88eee,-0x9(%rax) 7: 3b 8a 00 eb b0 66 cmp 0x66b0eb00(%rdx),%ecx d: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 12: be 01 00 00 00 mov $0x1,%esi 17: e9 e6 1e 2d 00 jmpq 0x2d1f02 1c: cc int3 1d: cc int3 1e: cc int3 1f: cc int3 20: cc int3 21: cc int3 22: 89 ff mov %edi,%edi 24: 89 b7 00 c0 5f ff mov %esi,-0xa04000(%rdi) * 2a: c3 retq <-- trapping instruction 2b: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 32: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 39: fc ff df 3c: 53 push %rbx 3d: 89 fb mov %edi,%ebx 3f: 48 rex.W