rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=146237, q=24165) rcu: All QSes seen, last rcu_preempt kthread activity 5205 (4295028807-4295023602), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 5206 jiffies! g146237 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:28952 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6250 schedule+0xd2/0x260 kernel/sched/core.c:6323 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 14574 Comm: syz-executor.3 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hlock_class kernel/locking/lockdep.c:203 [inline] RIP: 0010:hlock_class kernel/locking/lockdep.c:192 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4713 [inline] RIP: 0010:__lock_acquire+0x739/0x54a0 kernel/locking/lockdep.c:4965 Code: 19 29 90 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 c6 33 00 00 8b 05 96 63 cd 0e 85 c0 0f 84 3a 07 00 00 31 c0 e9 0f ff ff ff <4c> 8b 64 24 58 40 38 6c 24 50 76 0d e8 d6 7e 7a 02 85 c0 0f 85 60 RSP: 0018:ffffc90000fd8698 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000058 RCX: ffffffff815bb5ed RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fd480d8 RBP: 0000000000000002 R08: 0000000000000000 R09: ffffffff8fd43a0f R10: fffffbfff1fa8741 R11: 0000000000000000 R12: 0000000000000002 R13: ffff88803f3f8200 R14: ffff88803f3f8c60 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055e7ad8b1048 CR3: 000000003a07b000 CR4: 00000000003506e0 DR0: 00000000000043ce DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 debug_object_deactivate lib/debugobjects.c:735 [inline] debug_object_deactivate+0x101/0x300 lib/debugobjects.c:723 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline] debug_deactivate kernel/time/hrtimer.c:481 [inline] __run_hrtimer kernel/time/hrtimer.c:1653 [inline] __hrtimer_run_queues+0x3f8/0xe50 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:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5593 Code: 62 a6 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90000fd8c48 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920001fb18b RCX: ffffffff815bc52f RDX: 1ffff11007e7f18b RSI: 0000000000000100 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8fd43b97 R10: fffffbfff1fa8772 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffc90000fd8d70 R15: 0000000000000000 call_timer_fn+0x12b/0x6b0 kernel/time/timer.c:1418 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:native_pmd_val arch/x86/include/asm/pgtable_types.h:390 [inline] RIP: 0010:pmd_pfn arch/x86/include/asm/pgtable.h:192 [inline] RIP: 0010:pte_lockptr include/linux/mm.h:2339 [inline] RIP: 0010:zap_pte_range mm/memory.c:1320 [inline] RIP: 0010:zap_pmd_range mm/memory.c:1481 [inline] RIP: 0010:zap_pud_range mm/memory.c:1510 [inline] RIP: 0010:zap_p4d_range mm/memory.c:1531 [inline] RIP: 0010:unmap_page_range+0x78a/0x2a10 mm/memory.c:1552 Code: 00 48 89 44 24 30 e8 75 71 cb ff 48 8b 7c 24 30 31 f6 ba 10 00 00 00 e8 e4 66 11 00 48 8b 44 24 28 48 c1 e8 03 42 80 3c 30 00 <0f> 85 b0 1d 00 00 48 8b 44 24 28 31 ff 48 8b 18 48 89 de e8 1e 77 RSP: 0018:ffffc90009d577a8 EFLAGS: 00000246 RAX: 1ffff1100577d332 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90009d578a0 RBP: 0000000000000063 R08: 0000000000000001 R09: ffffc90009d57890 R10: fffff520013aaf13 R11: 0000000000000000 R12: 0000000000000000 R13: 00007fce6643f000 R14: dffffc0000000000 R15: 0000000000000000 unmap_single_vma+0x198/0x310 mm/memory.c:1597 unmap_vmas+0x16b/0x2f0 mm/memory.c:1629 exit_mmap+0x1d0/0x630 mm/mmap.c:3171 __mmput+0x122/0x4b0 kernel/fork.c:1113 mmput+0x56/0x60 kernel/fork.c:1134 exit_mm kernel/exit.c:507 [inline] do_exit+0xb27/0x2b40 kernel/exit.c:819 do_group_exit+0x125/0x310 kernel/exit.c:929 get_signal+0x47d/0x21d0 kernel/signal.c:2820 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fce68f4bae9 Code: Unable to access opcode bytes at RIP 0x7fce68f4babf. RSP: 002b:00007fce6647f218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fce6905f0e8 RCX: 00007fce68f4bae9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fce6905f0e8 RBP: 00007fce6905f0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fce6905f0ec R13: 00007fff0e205bdf R14: 00007fce6647f300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 19 29 sbb %ebp,(%rcx) 2: 90 nop 3: 83 e0 07 and $0x7,%eax 6: 83 c0 03 add $0x3,%eax 9: 38 d0 cmp %dl,%al b: 7c 08 jl 0x15 d: 84 d2 test %dl,%dl f: 0f 85 c6 33 00 00 jne 0x33db 15: 8b 05 96 63 cd 0e mov 0xecd6396(%rip),%eax # 0xecd63b1 1b: 85 c0 test %eax,%eax 1d: 0f 84 3a 07 00 00 je 0x75d 23: 31 c0 xor %eax,%eax 25: e9 0f ff ff ff jmpq 0xffffff39 * 2a: 4c 8b 64 24 58 mov 0x58(%rsp),%r12 <-- trapping instruction 2f: 40 38 6c 24 50 cmp %bpl,0x50(%rsp) 34: 76 0d jbe 0x43 36: e8 d6 7e 7a 02 callq 0x27a7f11 3b: 85 c0 test %eax,%eax 3d: 0f .byte 0xf 3e: 85 .byte 0x85 3f: 60 (bad)