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BUG: KCSAN: data-race in __percpu_ref_switch_mode / percpu_ref_switch_to_atomic_rcu

write to 0xffff88815bddf950 of 8 bytes by interrupt on cpu 1:
 percpu_ref_call_confirm_rcu lib/percpu-refcount.c:156 [inline]
 percpu_ref_switch_to_atomic_rcu+0x188/0x360 lib/percpu-refcount.c:205
 rcu_do_batch kernel/rcu/tree.c:2558 [inline]
 rcu_core+0xb95/0xd50 kernel/rcu/tree.c:2793
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2806
 __do_softirq+0x12c/0x275 kernel/softirq.c:559
 invoke_softirq kernel/softirq.c:433 [inline]
 __irq_exit_rcu+0xa5/0xb0 kernel/softirq.c:637
 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647
 kcsan_setup_watchpoint+0x8b/0x3e0 kernel/kcsan/core.c:437
 page_needs_cow_for_dma include/linux/mm.h:1341 [inline]
 copy_present_page mm/memory.c:827 [inline]
 copy_present_pte mm/memory.c:870 [inline]
 copy_pte_range+0x3a4/0x1460 mm/memory.c:984
 copy_pmd_range mm/memory.c:1064 [inline]
 copy_pud_range mm/memory.c:1101 [inline]
 copy_p4d_range mm/memory.c:1125 [inline]
 copy_page_range+0x5da/0x8e0 mm/memory.c:1198
 dup_mmap+0x6ab/0x9c0 kernel/fork.c:598
 dup_mm+0x7c/0x210 kernel/fork.c:1374
 copy_mm kernel/fork.c:1426 [inline]
 copy_process+0x1203/0x2e00 kernel/fork.c:2116
 kernel_clone+0x14b/0x680 kernel/fork.c:2503
 __do_sys_clone kernel/fork.c:2620 [inline]
 __se_sys_clone kernel/fork.c:2604 [inline]
 __x64_sys_clone+0xb4/0xe0 kernel/fork.c:2604
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88815bddf950 of 8 bytes by task 7907 on cpu 0:
 __percpu_ref_switch_mode+0xe6/0x3b0 lib/percpu-refcount.c:275
 percpu_ref_resurrect+0xc2/0x110 lib/percpu-refcount.c:473
 io_refs_resurrect fs/io_uring.c:1104 [inline]
 __io_uring_register fs/io_uring.c:10026 [inline]
 __do_sys_io_uring_register+0xd32/0x1b90 fs/io_uring.c:10146
 __se_sys_io_uring_register fs/io_uring.c:10126 [inline]
 __x64_sys_io_uring_register+0x4f/0x60 fs/io_uring.c:10126
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffffffff818a4400 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7907 Comm: syz-executor.0 Not tainted 5.13.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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