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BUG: KCSAN: data-race in ondemand_readahead / ondemand_readahead

read to 0xffff888112700978 of 8 bytes by task 3877 on cpu 0:
 ondemand_readahead+0x133/0x6b0 mm/readahead.c:581
 page_cache_async_ra+0x94/0xa0 mm/readahead.c:718
 do_async_mmap_readahead mm/filemap.c:3203 [inline]
 filemap_fault+0x2d3/0xa60 mm/filemap.c:3299
 __do_fault+0xb6/0x200 mm/memory.c:4556
 do_read_fault mm/memory.c:4920 [inline]
 do_fault mm/memory.c:5050 [inline]
 do_pte_missing mm/memory.c:3897 [inline]
 handle_pte_fault mm/memory.c:5380 [inline]
 __handle_mm_fault mm/memory.c:5523 [inline]
 handle_mm_fault+0xdeb/0x2a80 mm/memory.c:5688
 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x296/0x650 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
 fault_in_readable+0xf8/0x1b0
 fault_in_iov_iter_readable+0x152/0x190 lib/iov_iter.c:94
 generic_perform_write+0x106/0x410 mm/filemap.c:4005
 ext4_buffered_write_iter+0x1f6/0x380 fs/ext4/file.c:299
 ext4_file_write_iter+0x29f/0xe30
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0x78f/0x900 fs/read_write.c:590
 ksys_write+0xeb/0x1b0 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:652
 x64_sys_call+0x27ef/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff888112700978 of 8 bytes by task 3873 on cpu 1:
 ondemand_readahead+0x588/0x6b0 mm/readahead.c:607
 page_cache_async_ra+0x94/0xa0 mm/readahead.c:718
 do_async_mmap_readahead mm/filemap.c:3203 [inline]
 filemap_fault+0x2d3/0xa60 mm/filemap.c:3299
 __do_fault+0xb6/0x200 mm/memory.c:4556
 do_read_fault mm/memory.c:4920 [inline]
 do_fault mm/memory.c:5050 [inline]
 do_pte_missing mm/memory.c:3897 [inline]
 handle_pte_fault mm/memory.c:5380 [inline]
 __handle_mm_fault mm/memory.c:5523 [inline]
 handle_mm_fault+0xdeb/0x2a80 mm/memory.c:5688
 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x296/0x650 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
 rep_movs_alternative+0x30/0x70 arch/x86/lib/copy_user_64.S:50
 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:125 [inline]
 _copy_from_user+0x80/0xd0 lib/usercopy.c:28
 copy_from_user include/linux/uaccess.h:183 [inline]
 copy_msghdr_from_user+0x54/0x2a0 net/socket.c:2515
 recvmsg_copy_msghdr net/socket.c:2770 [inline]
 ___sys_recvmsg net/socket.c:2842 [inline]
 do_recvmmsg+0x290/0x720 net/socket.c:2940
 __sys_recvmmsg net/socket.c:3019 [inline]
 __do_sys_recvmmsg net/socket.c:3042 [inline]
 __se_sys_recvmmsg net/socket.c:3035 [inline]
 __x64_sys_recvmmsg+0xe2/0x170 net/socket.c:3035
 x64_sys_call+0x271d/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:300
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000000000f7 -> 0x00000000000000f8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3873 Comm: syz-executor.3 Not tainted 6.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
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