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BUG: KCSAN: data-race in __anon_vma_prepare / handle_mm_fault

write to 0xffff88811c262d00 of 8 bytes by task 3963 on cpu 0:
 __anon_vma_prepare+0x172/0x2f0 mm/rmap.c:212
 __vmf_anon_prepare mm/memory.c:3673 [inline]
 vmf_anon_prepare mm/internal.h:432 [inline]
 do_anonymous_page mm/memory.c:5218 [inline]
 do_pte_missing mm/memory.c:4399 [inline]
 handle_pte_fault mm/memory.c:6273 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x1d91/0x2c60 mm/memory.c:6580
 do_user_addr_fault+0x3fe/0x1080 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
 rep_movs_alternative+0x11/0x90 arch/x86/lib/copy_user_64.S:46
 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
 _inline_copy_to_user include/linux/uaccess.h:206 [inline]
 _copy_to_user+0x7c/0xa0 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:236 [inline]
 do_timer_create+0x663/0x980 kernel/time/posix-timers.c:532
 __do_sys_timer_create kernel/time/posix-timers.c:-1 [inline]
 __se_sys_timer_create kernel/time/posix-timers.c:573 [inline]
 __x64_sys_timer_create+0xb9/0xe0 kernel/time/posix-timers.c:573
 x64_sys_call+0x29c8/0x3000 arch/x86/include/generated/asm/syscalls_64.h:223
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811c262d00 of 8 bytes by task 3962 on cpu 1:
 __vmf_anon_prepare mm/memory.c:3667 [inline]
 vmf_anon_prepare mm/internal.h:432 [inline]
 do_anonymous_page mm/memory.c:5218 [inline]
 do_pte_missing mm/memory.c:4399 [inline]
 handle_pte_fault mm/memory.c:6273 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0xec1/0x2c60 mm/memory.c:6580
 do_user_addr_fault+0x630/0x1080 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

value changed: 0x0000000000000000 -> 0xffff88811c8685b0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3962 Comm: syz.3.140 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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