syzbot

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BUG: KCSAN: data-race in do_sync_mmap_readahead / do_sync_mmap_readahead

write to 0xffff888137d0ef84 of 4 bytes by task 4089 on cpu 1:
 do_sync_mmap_readahead+0x3f5/0x450 mm/filemap.c:3197
 filemap_fault+0x3e6/0xbf0 mm/filemap.c:3291
 __do_fault mm/memory.c:4204 [inline]
 do_shared_fault mm/memory.c:4635 [inline]
 do_fault mm/memory.c:4709 [inline]
 do_pte_missing mm/memory.c:3669 [inline]
 handle_pte_fault mm/memory.c:4978 [inline]
 __handle_mm_fault mm/memory.c:5119 [inline]
 handle_mm_fault+0x170f/0x2cc0 mm/memory.c:5284
 do_user_addr_fault arch/x86/mm/fault.c:1413 [inline]
 handle_page_fault arch/x86/mm/fault.c:1505 [inline]
 exc_page_fault+0x2f7/0x6c0 arch/x86/mm/fault.c:1561
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

write to 0xffff888137d0ef84 of 4 bytes by task 4090 on cpu 0:
 do_sync_mmap_readahead+0x3f5/0x450 mm/filemap.c:3197
 filemap_fault+0x3e6/0xbf0 mm/filemap.c:3291
 __do_fault mm/memory.c:4204 [inline]
 do_read_fault mm/memory.c:4568 [inline]
 do_fault mm/memory.c:4705 [inline]
 do_pte_missing mm/memory.c:3669 [inline]
 handle_pte_fault mm/memory.c:4978 [inline]
 __handle_mm_fault mm/memory.c:5119 [inline]
 handle_mm_fault+0x15e2/0x2cc0 mm/memory.c:5284
 do_user_addr_fault arch/x86/mm/fault.c:1413 [inline]
 handle_page_fault arch/x86/mm/fault.c:1505 [inline]
 exc_page_fault+0x2f7/0x6c0 arch/x86/mm/fault.c:1561
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
 rep_movs_alternative+0x30/0x70 arch/x86/lib/copy_user_64.S:50
 copy_user_generic arch/x86/include/asm/uaccess_64.h:112 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:127 [inline]
 _copy_from_user+0x80/0xd0 lib/usercopy.c:23
 copy_from_user include/linux/uaccess.h:183 [inline]
 copy_msghdr_from_user+0x54/0x2a0 net/socket.c:2471
 recvmsg_copy_msghdr net/socket.c:2726 [inline]
 ___sys_recvmsg net/socket.c:2798 [inline]
 do_recvmmsg+0x290/0x720 net/socket.c:2896
 __sys_recvmmsg net/socket.c:2975 [inline]
 __do_sys_recvmmsg net/socket.c:2998 [inline]
 __se_sys_recvmmsg net/socket.c:2991 [inline]
 __x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2991
 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 -> 0x00000008

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4090 Comm: syz-executor.2 Not tainted 6.6.0-rc3-syzkaller-00252-ge81a2dabc3f3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
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