==================================================================
BUG: KCSAN: data-race in __anon_vma_prepare / wp_page_copy

write to 0xffff8881563df088 of 8 bytes by task 31785 on cpu 1:
 __anon_vma_prepare+0x12f/0x2d0 mm/rmap.c:207
 anon_vma_prepare include/linux/rmap.h:149 [inline]
 wp_page_copy+0xb0e/0x10c0 mm/memory.c:2994
 do_wp_page+0x5a8/0xba0 include/linux/spinlock_api_smp.h:152
 handle_pte_fault mm/memory.c:4576 [inline]
 __handle_mm_fault mm/memory.c:4693 [inline]
 handle_mm_fault+0xb11/0x1a50 mm/memory.c:4791
 do_user_addr_fault+0x609/0xbe0 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0x91/0x220 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568
 __put_user_nocheck_4+0x3/0x11
 ____sys_recvmsg+0x201/0x310 net/socket.c:2624
 ___sys_recvmsg net/socket.c:2653 [inline]
 do_recvmmsg+0x35c/0x9f0 net/socket.c:2747
 __sys_recvmmsg net/socket.c:2826 [inline]
 __do_sys_recvmmsg net/socket.c:2849 [inline]
 __se_sys_recvmmsg net/socket.c:2842 [inline]
 __x64_sys_recvmmsg+0xcf/0x150 net/socket.c:2842
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881563df088 of 8 bytes by task 31779 on cpu 0:
 anon_vma_prepare include/linux/rmap.h:146 [inline]
 wp_page_copy+0x5f/0x10c0 mm/memory.c:2994
 do_wp_page+0x5a8/0xba0 include/linux/spinlock_api_smp.h:152
 handle_pte_fault mm/memory.c:4576 [inline]
 __handle_mm_fault mm/memory.c:4693 [inline]
 handle_mm_fault+0xb11/0x1a50 mm/memory.c:4791
 do_user_addr_fault+0x609/0xbe0 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0x91/0x220 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568

value changed: 0x0000000000000000 -> 0xffff88812fb38e60

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31779 Comm: syz-executor.5 Not tainted 5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================