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BUG: KCSAN: data-race in do_sync_mmap_readahead / do_sync_mmap_readahead

write to 0xffff888137470e80 of 4 bytes by task 21883 on cpu 0:
 do_sync_mmap_readahead+0x335/0x3b0 mm/filemap.c:3202
 filemap_fault+0x3d6/0xb70 mm/filemap.c:3297
 __do_fault mm/memory.c:4198 [inline]
 do_shared_fault mm/memory.c:4602 [inline]
 do_fault mm/memory.c:4674 [inline]
 do_pte_missing mm/memory.c:3664 [inline]
 handle_pte_fault mm/memory.c:4939 [inline]
 __handle_mm_fault mm/memory.c:5079 [inline]
 handle_mm_fault+0x131b/0x2c10 mm/memory.c:5233
 do_user_addr_fault arch/x86/mm/fault.c:1392 [inline]
 handle_page_fault arch/x86/mm/fault.c:1486 [inline]
 exc_page_fault+0x24d/0x650 arch/x86/mm/fault.c:1542
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

write to 0xffff888137470e80 of 4 bytes by task 21892 on cpu 1:
 do_sync_mmap_readahead+0x335/0x3b0 mm/filemap.c:3202
 filemap_fault+0x3d6/0xb70 mm/filemap.c:3297
 __do_fault mm/memory.c:4198 [inline]
 do_shared_fault mm/memory.c:4602 [inline]
 do_fault mm/memory.c:4674 [inline]
 do_pte_missing mm/memory.c:3664 [inline]
 handle_pte_fault mm/memory.c:4939 [inline]
 __handle_mm_fault mm/memory.c:5079 [inline]
 handle_mm_fault+0x131b/0x2c10 mm/memory.c:5233
 do_user_addr_fault arch/x86/mm/fault.c:1392 [inline]
 handle_page_fault arch/x86/mm/fault.c:1486 [inline]
 exc_page_fault+0x24d/0x650 arch/x86/mm/fault.c:1542
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
 __put_user_4+0x11/0x20 arch/x86/lib/putuser.S:89
 __sys_sendmmsg+0x38b/0x500 net/socket.c:2639
 __do_sys_sendmmsg net/socket.c:2663 [inline]
 __se_sys_sendmmsg net/socket.c:2660 [inline]
 __x64_sys_sendmmsg+0x57/0x60 net/socket.c:2660
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000000 -> 0x00000020

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 21892 Comm: syz-executor.2 Not tainted 6.5.0-rc3-syzkaller-00225-gf837f0a3c948 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
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