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BUG: KCSAN: data-race in __anon_vma_prepare / do_anonymous_page

write to 0xffff8881372e7088 of 8 bytes by task 4341 on cpu 0:
 __anon_vma_prepare+0x130/0x2c0 mm/rmap.c:208
 anon_vma_prepare include/linux/rmap.h:149 [inline]
 do_anonymous_page+0x7a6/0x8d0 mm/memory.c:3777
 handle_pte_fault mm/memory.c:4568 [inline]
 __handle_mm_fault mm/memory.c:4705 [inline]
 handle_mm_fault+0x814/0x1590 mm/memory.c:4803
 do_user_addr_fault+0x617/0xb90 arch/x86/mm/fault.c:1397
 handle_page_fault arch/x86/mm/fault.c:1484 [inline]
 exc_page_fault+0x91/0x290 arch/x86/mm/fault.c:1540
 asm_exc_page_fault+0x1e/0x30
 __put_user_nocheck_4+0x3/0x11
 data_sock_ioctl+0xb2/0x5b0 drivers/isdn/mISDN/socket.c:367
 sock_do_ioctl+0x7d/0x1b0 net/socket.c:1122
 sock_ioctl+0x35a/0x570 net/socket.c:1239
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:860
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881372e7088 of 8 bytes by task 4335 on cpu 1:
 anon_vma_prepare include/linux/rmap.h:146 [inline]
 do_anonymous_page+0x12c/0x8d0 mm/memory.c:3777
 handle_pte_fault mm/memory.c:4568 [inline]
 __handle_mm_fault mm/memory.c:4705 [inline]
 handle_mm_fault+0x814/0x1590 mm/memory.c:4803
 do_user_addr_fault+0x617/0xb90 arch/x86/mm/fault.c:1397
 handle_page_fault arch/x86/mm/fault.c:1484 [inline]
 exc_page_fault+0x91/0x290 arch/x86/mm/fault.c:1540
 asm_exc_page_fault+0x1e/0x30

value changed: 0x0000000000000000 -> 0xffff888137ce19b0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4335 Comm: syz-executor.2 Not tainted 5.17.0-rc2-syzkaller-00060-g88808fbbead4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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