rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): (detected by 1, t=10502 jiffies, g=15977, q=369) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295109012-4295098510), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g15977 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:28864 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline] rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169 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: 13803 Comm: syz-executor.5 Not tainted 5.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mark_lock+0x2/0x17b0 kernel/locking/lockdep.c:4554 Code: c0 fe ff ff ff c3 66 90 be 00 00 02 00 48 c7 c7 80 95 01 8f e8 1f 25 79 02 48 98 c3 66 66 2e 0f 1f 84 00 00 00 00 00 90 41 57 <41> 56 41 55 41 54 41 89 d4 48 ba 00 00 00 00 00 fc ff df 55 53 48 RSP: 0018:ffffc900000076e0 EFLAGS: 00000002 RAX: 0000000000000007 RBX: ffff88803a622614 RCX: 1ffffffff1f9b1d2 RDX: 0000000000000005 RSI: ffff88803a6226a8 RDI: ffff88803a621c40 RBP: ffff88803a6226ca R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88803a6226a8 R13: ffff88803a621c40 R14: 0000000000066000 R15: 0000000000000000 FS: 00007f3a2f457700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000004 CR3: 0000000027762000 CR4: 0000000000350ef0 Call Trace: mark_usage kernel/locking/lockdep.c:4480 [inline] __lock_acquire+0x14d7/0x54a0 kernel/locking/lockdep.c:4969 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 seqcount_lockdep_reader_access include/linux/seqlock.h:103 [inline] ktime_get+0x7c/0x470 kernel/time/timekeeping.c:827 clockevents_program_event+0x141/0x370 kernel/time/clockevents.c:326 tick_program_event+0xac/0x140 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x414/0xa00 kernel/time/hrtimer.c:1676 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:rcu_is_watching+0x1/0xc0 kernel/rcu/tree.c:1156 Code: 08 48 89 ef 5d e9 5f a3 cb 07 48 c7 c7 6c b2 6c 8d 48 89 34 24 e8 cf 6d 5a 00 48 8b 34 24 eb bb 66 0f 1f 84 00 00 00 00 00 55 <53> 65 ff 05 17 7c a0 7e e8 12 04 c9 07 48 c7 c3 00 29 05 00 83 f8 RSP: 0018:ffffc90000007b60 EFLAGS: 00000282 RAX: 0000000000000000 RBX: ffff888013fddf60 RCX: 255701fbb9802d42 RDX: 1ffff110074c44c5 RSI: 0000000000000101 RDI: 0000000000000000 RBP: ffff888038df0d20 R08: 0000000000000000 R09: ffffffff8fcd58a7 R10: fffffbfff1f9ab14 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888038df0d20 R14: 0000000000000000 R15: ffff888013fddf60 rcu_read_lock include/linux/rcupdate.h:688 [inline] __ieee80211_beacon_get+0xab/0x1ac0 net/mac80211/tx.c:4990 ieee80211_beacon_get_tim+0x88/0x930 net/mac80211/tx.c:5175 ieee80211_beacon_get include/net/mac80211.h:4962 [inline] mac80211_hwsim_beacon_tx+0x111/0x930 drivers/net/wireless/mac80211_hwsim.c:1808 __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:1537 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1618 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 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:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__queue_me kernel/futex.c:2240 [inline] RIP: 0010:queue_me kernel/futex.c:2258 [inline] RIP: 0010:futex_wait_queue_me+0x168/0x520 kernel/futex.c:2585 Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 5d 03 00 00 48 89 6b 20 49 8d 74 24 48 48 89 df e8 fc e0 87 02 48 8d 7b 28 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 65 4c 8b 34 25 RSP: 0018:ffffc90002ddfa60 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffffc90002ddfb70 RCX: 0000000000000000 RDX: ffff88803a621c40 RSI: ffffffff81698384 RDI: ffffc90002ddfb98 RBP: ffffc90002ddfb88 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff83f16789 R11: 0000000000000000 R12: ffffc90000e08c80 R13: 0000000000000000 R14: ffffc90002ddfb70 R15: 0000000000000000 futex_wait+0x1db/0x5f0 kernel/futex.c:2704 do_futex+0x250/0x1770 kernel/futex.c:3730 __do_sys_futex+0xdc/0x3b0 kernel/futex.c:3807 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: 0033:0x4665e9 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:00007f3a2f457218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000056bf88 RCX: 00000000004665e9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf88 RBP: 000000000056bf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf8c R13: 00007ffe337c591f R14: 00007f3a2f457300 R15: 0000000000022000