rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10501 ticks this GP) idle=6ee/1/0x4000000000000000 softirq=118224/118224 fqs=5239 (t=10502 jiffies g=239457 q=3887) NMI backtrace for cpu 0 CPU: 0 PID: 22596 Comm: syz-executor.2 Not tainted 5.9.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x194/0x1cf kernel/rcu/tree_stall.h:318 print_cpu_stall kernel/rcu/tree_stall.h:551 [inline] check_cpu_stall kernel/rcu/tree_stall.h:625 [inline] rcu_pending kernel/rcu/tree.c:3637 [inline] rcu_sched_clock_irq.cold+0x5b3/0xccd kernel/rcu/tree.c:2519 update_process_times+0x25/0xa0 kernel/time/timer.c:1710 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x1d1/0x2a0 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650 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 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0x4c/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x8c/0xe0 kernel/locking/spinlock.c:191 Code: 48 c7 c0 08 36 b6 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 37 48 83 3d 33 6a c0 01 00 74 22 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 95 e7 59 f9 65 8b 05 8e 32 0c 78 RSP: 0018:ffffc90000007bf0 EFLAGS: 00000282 RAX: 1ffffffff136c6c1 RBX: 0000000000000282 RCX: 0000000000000002 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000282 RBP: ffff8880ae6255c0 R08: 0000000000000001 R09: ffffffff8c5f0aaf R10: fffffbfff18be155 R11: 0000000000000001 R12: 000000010001fa68 R13: ffff8880ae6255c0 R14: 0000000000000000 R15: 00000000ffffffff __mod_timer+0x825/0xd90 kernel/time/timer.c:1066 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413 expire_timers kernel/time/timer.c:1458 [inline] __run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755 __run_timers kernel/time/timer.c:1736 [inline] run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768 __do_softirq+0x2de/0xa24 kernel/softirq.c:298 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __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] do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x1f3/0x230 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:slab_alloc mm/slab.c:3305 [inline] RIP: 0010:kmem_cache_alloc+0x100/0x3a0 mm/slab.c:3482 Code: 41 f7 c4 00 02 00 00 4c 89 7c 24 08 0f 84 d2 00 00 00 e8 03 11 c6 ff 48 83 3d 53 41 02 08 00 0f 84 9b 02 00 00 4c 89 e7 57 9d <0f> 1f 44 00 00 4c 8b 44 24 08 41 0f 18 08 e9 99 01 00 00 f6 c7 01 RSP: 0018:ffffc9000963f7b8 EFLAGS: 00000282 RAX: 00000000000005a7 RBX: 0000000000000cc0 RCX: 0000000000000006 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000282 RBP: ffff8880aa04fc00 R08: 0000000000000001 R09: ffffffff8c5f09f7 R10: fffffbfff18be13e R11: 0000000000000000 R12: 0000000000000282 R13: 0000000000000cc0 R14: ffff8880aa04fc00 R15: ffff888095333ae0 ptlock_alloc+0x1d/0x70 mm/memory.c:5078 ptlock_init include/linux/mm.h:2161 [inline] pgtable_pte_page_ctor include/linux/mm.h:2188 [inline] __pte_alloc_one include/asm-generic/pgalloc.h:66 [inline] pte_alloc_one+0x68/0x190 arch/x86/mm/pgtable.c:33 __pte_alloc+0x1b/0x310 mm/memory.c:427 copy_pte_range mm/memory.c:827 [inline] copy_pmd_range mm/memory.c:903 [inline] copy_pud_range mm/memory.c:937 [inline] copy_p4d_range mm/memory.c:959 [inline] copy_page_range+0x1a89/0x26a0 mm/memory.c:1021 dup_mmap kernel/fork.c:592 [inline] dup_mm+0x98f/0x1300 kernel/fork.c:1354 copy_mm kernel/fork.c:1410 [inline] copy_process+0x28e4/0x6920 kernel/fork.c:2069 _do_fork+0xe8/0xb10 kernel/fork.c:2428 __do_sys_clone+0xc8/0x110 kernel/fork.c:2545 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d4d9 Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f30b575ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000001f40 RCX: 000000000045d4d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000000118cf90 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffe8db6880f R14: 00007f30b575f9c0 R15: 000000000118cf4c