rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=6da/1/0x4000000000000000 softirq=86696/86696 fqs=19 (detected by 0, t=10502 jiffies, g=153793, q=83) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3695 Comm: kworker/u4:6 Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:193 Code: 0b e8 24 00 00 00 0f 0b 66 90 53 48 89 fb e8 17 00 00 00 48 8b 3d b8 b1 f8 07 48 89 de 5b e9 87 8d 3e 00 cc cc cc cc cc cc cc <48> 8b 04 24 65 48 8b 0c 25 00 fe 01 00 65 8b 15 e8 81 8d 7e f7 c2 RSP: 0018:ffffc90000da8d88 EFLAGS: 00000046 RAX: ffffffff81653504 RBX: 00000000fffffffd RCX: ffff88809962e080 RDX: 0000000080010000 RSI: ffffc90000da8e50 RDI: ffff88808fb65340 RBP: ffff8880ae9275c4 R08: ffffffff817a2224 R09: ffffed1015d24eb1 R10: ffffed1015d24eb1 R11: 0000000000000000 R12: ffff88808fb65340 R13: 1ffff11015d24ed2 R14: ffffc90000da8e50 R15: ffff88808fb65340 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000508ab0 CR3: 00000000a8767000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> arch_static_branch arch/x86/include/asm/jump_label.h:25 [inline] static_key_false include/linux/jump_label.h:200 [inline] trace_hrtimer_expire_entry+0x1e/0x2d0 include/trace/events/timer.h:232 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x3ef/0x930 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1646 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711 </IRQ> __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] sysvec_apic_timer_interrupt+0xb9/0x130 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:765 [inline] RIP: 0010:lock_acquire+0x1bf/0x720 kernel/locking/lockdep.c:4962 Code: c1 e8 03 80 3c 10 00 74 0c 48 c7 c7 f0 c7 2b 89 e8 06 ee 59 00 48 83 3d ee 3a d2 07 00 0f 84 09 05 00 00 48 8b 7c 24 10 57 9d <0f> 1f 44 00 00 65 48 8b 04 25 28 00 00 00 48 3b 44 24 50 0f 85 e0 RSP: 0018:ffffc9000d8f7b40 EFLAGS: 00000282 RAX: 1ffffffff12578fe RBX: 0000000000000000 RCX: 913934eee713b000 RDX: dffffc0000000000 RSI: ffff88809962e9c8 RDI: 0000000000000282 RBP: 1ffff110132c5d29 R08: dffffc0000000000 R09: fffffbfff163349f R10: fffffbfff163349f R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffff88809962e94c R15: 0000000000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:241 rcu_read_lock include/linux/rcupdate.h:634 [inline] inet_twsk_purge+0xd6/0x820 net/ipv4/inet_timewait_sock.c:268 ops_exit_list net/core/net_namespace.c:189 [inline] cleanup_net+0x79c/0xba0 net/core/net_namespace.c:603 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 rcu: rcu_preempt kthread starved for 10464 jiffies! g153793 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: rcu_preempt R running task 28912 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x7d3/0xc40 kernel/sched/core.c:4178