syzbot

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BUG: KCSAN: data-race in do_sync_mmap_readahead / ondemand_readahead

write to 0xffff88815b0bec78 of 8 bytes by task 17540 on cpu 0:
 do_sync_mmap_readahead+0x3ce/0x450 mm/filemap.c:3195
 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
 faultin_page mm/gup.c:956 [inline]
 __get_user_pages+0x402/0xe40 mm/gup.c:1239
 populate_vma_page_range mm/gup.c:1666 [inline]
 __mm_populate+0x216/0x330 mm/gup.c:1775
 mm_populate include/linux/mm.h:3305 [inline]
 vm_mmap_pgoff+0x1a7/0x240 mm/util.c:551
 ksys_mmap_pgoff+0x2b8/0x330 mm/mmap.c:1400
 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

write to 0xffff88815b0bec78 of 8 bytes by task 17541 on cpu 1:
 ondemand_readahead+0x2a4/0x690 mm/readahead.c:583
 page_cache_async_ra+0x94/0xa0 mm/readahead.c:717
 do_async_mmap_readahead mm/filemap.c:3227 [inline]
 filemap_fault+0x3a0/0xbf0 mm/filemap.c:3281
 __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
 faultin_page mm/gup.c:956 [inline]
 __get_user_pages+0x402/0xe40 mm/gup.c:1239
 populate_vma_page_range mm/gup.c:1666 [inline]
 __mm_populate+0x216/0x330 mm/gup.c:1775
 mm_populate include/linux/mm.h:3305 [inline]
 vm_mmap_pgoff+0x1a7/0x240 mm/util.c:551
 ksys_mmap_pgoff+0x2b8/0x330 mm/mmap.c:1400
 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: 0x00000000000003a0 -> 0x00000000000003b0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17541 Comm: syz-executor.2 Not tainted 6.6.0-rc2-syzkaller-00337-gd90b0276af8f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
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