rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=8a2/1/0x4000000000000000 softirq=105257/105257 fqs=1 (detected by 0, t=10502 jiffies, g=145053, q=57) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 30033 Comm: syz-executor.1 Not tainted 5.8.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_memory_region+0x16/0x180 mm/kasan/generic.c:191 Code: 01 0f 1f 00 48 89 f2 be f8 00 00 00 e9 43 39 ff 01 0f 1f 00 48 85 f6 0f 84 70 01 00 00 49 89 f9 41 54 44 0f b6 c2 49 01 f1 55 <53> 0f 82 18 01 00 00 48 b8 ff ff ff ff ff 7f ff ff 48 39 c7 0f 86 RSP: 0018:ffffc90000da8b78 EFLAGS: 00000096 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff8159a478 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8c599a28 RBP: ffff8880327faae0 R08: 0000000000000000 R09: ffffffff8c599a30 R10: 0000000000000050 R11: 0000000000000001 R12: ffff8880327fa1c0 R13: 0000000000000059 R14: ffff8880ae727758 R15: 0000000000044000 FS: 00007faebca57700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f820000 CR3: 000000006ed10000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:56 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline] hlock_class kernel/locking/lockdep.c:179 [inline] check_wait_context kernel/locking/lockdep.c:4054 [inline] __lock_acquire+0x408/0x56e0 kernel/locking/lockdep.c:4330 lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:4959 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x5b/0x80 kernel/locking/spinlock.c:167 __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x252/0xfc0 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646 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 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711 __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+0xe0/0x120 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:587 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:765 [inline] RIP: 0010:lock_acquire+0x270/0xad0 kernel/locking/lockdep.c:4962 Code: 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 f8 06 00 00 48 83 3d ad d0 5a 08 00 0f 84 a6 05 00 00 48 8b 7c 24 08 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 03 44 24 10 48 c7 RSP: 0018:ffffc90004157610 EFLAGS: 00000282 RAX: 1ffffffff1369c10 RBX: ffff8880327fa1c0 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 2886fd236c3909d4 RDI: 0000000000000282 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8c599a27 R10: fffffbfff18b3344 R11: 0000000000000000 R12: 0000000000000002 R13: ffffffff89bc11c0 R14: 0000000000000000 R15: ffff88809e71f028 rcu_lock_acquire include/linux/rcupdate.h:241 [inline] rcu_read_lock include/linux/rcupdate.h:634 [inline] lock_page_memcg+0x63/0x260 mm/memcontrol.c:1977 page_remove_rmap+0x25/0x1670 mm/rmap.c:1328 zap_pte_range mm/memory.c:1089 [inline] zap_pmd_range mm/memory.c:1193 [inline] zap_pud_range mm/memory.c:1222 [inline] zap_p4d_range mm/memory.c:1243 [inline] unmap_page_range+0xf3b/0x2940 mm/memory.c:1264 unmap_single_vma+0x198/0x300 mm/memory.c:1309 unmap_vmas+0x16f/0x2f0 mm/memory.c:1341 exit_mmap+0x2b1/0x510 mm/mmap.c:3150 __mmput+0x122/0x470 kernel/fork.c:1093 mmput+0x53/0x60 kernel/fork.c:1114 exit_mm kernel/exit.c:482 [inline] do_exit+0xa8f/0x2a40 kernel/exit.c:792 do_group_exit+0x125/0x310 kernel/exit.c:903 get_signal+0x40b/0x1ee0 kernel/signal.c:2743 do_signal+0x82/0x2520 arch/x86/kernel/signal.c:810 exit_to_usermode_loop arch/x86/entry/common.c:235 [inline] __prepare_exit_to_usermode+0x156/0x1f0 arch/x86/entry/common.c:269 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:393 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c1d9 Code: Bad RIP value. RSP: 002b:00007faebca56cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000078bf08 RCX: 000000000045c1d9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000078bf08 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffec09f8d0f R14: 00007faebca579c0 R15: 000000000078bf0c rcu: rcu_preempt kthread starved for 10500 jiffies! g145053 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 29120 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178 schedule+0xd0/0x2a0 kernel/sched/core.c:4253 schedule_timeout+0x148/0x250 kernel/time/timer.c:1897 rcu_gp_fqs_loop kernel/rcu/tree.c:1874 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2044 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293