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BUG: KCSAN: data-race in __anon_vma_prepare / do_anonymous_page

write to 0xffff888102a1da48 of 8 bytes by task 14729 on cpu 0:
 __anon_vma_prepare+0x12f/0x2d0 mm/rmap.c:207
 anon_vma_prepare include/linux/rmap.h:152 [inline]
 do_anonymous_page+0x7bc/0x8b0 mm/memory.c:3546
 handle_pte_fault mm/memory.c:4316 [inline]
 __handle_mm_fault mm/memory.c:4453 [inline]
 handle_mm_fault+0x96f/0x1a70 mm/memory.c:4551
 faultin_page mm/gup.c:850 [inline]
 __get_user_pages+0x947/0xee0 mm/gup.c:1069
 populate_vma_page_range mm/gup.c:1402 [inline]
 __mm_populate+0x24d/0x380 mm/gup.c:1450
 mm_populate include/linux/mm.h:2582 [inline]
 vm_mmap_pgoff+0x145/0x1d0 mm/util.c:524
 ksys_mmap_pgoff+0xe1/0x380 mm/mmap.c:1632
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888102a1da48 of 8 bytes by task 14709 on cpu 1:
 anon_vma_prepare include/linux/rmap.h:149 [inline]
 do_anonymous_page+0x130/0x8b0 mm/memory.c:3546
 handle_pte_fault mm/memory.c:4316 [inline]
 __handle_mm_fault mm/memory.c:4453 [inline]
 handle_mm_fault+0x96f/0x1a70 mm/memory.c:4551
 do_user_addr_fault+0x60c/0xc00 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0x94/0x230 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:577
 __clear_user arch/x86/lib/usercopy_64.c:24 [inline]
 clear_user+0x60/0xa0 arch/x86/lib/usercopy_64.c:54
 evdev_get_mask drivers/input/evdev.c:1023 [inline]
 evdev_do_ioctl drivers/input/evdev.c:1105 [inline]
 evdev_ioctl_handler+0x11ed/0x17e0 drivers/input/evdev.c:1272
 evdev_ioctl+0x20/0x30 drivers/input/evdev.c:1281
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14709 Comm: syz-executor.2 Not tainted 5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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