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BUG: KCSAN: data-race in __filemap_remove_folio / shmem_getpage_gfp

write to 0xffff888124e2b530 of 8 bytes by task 13915 on cpu 0:
 page_cache_delete mm/filemap.c:145 [inline]
 __filemap_remove_folio+0x1e1/0x2c0 mm/filemap.c:219
 __delete_from_page_cache include/linux/pagemap.h:934 [inline]
 __remove_mapping+0x49d/0x600 mm/vmscan.c:1319
 shrink_page_list+0x1508/0x2620 mm/vmscan.c:1894
 reclaim_pages+0x478/0x640 mm/vmscan.c:2638
 madvise_cold_or_pageout_pte_range+0x63f/0x680 mm/madvise.c:509
 walk_pmd_range mm/pagewalk.c:128 [inline]
 walk_pud_range mm/pagewalk.c:205 [inline]
 walk_p4d_range mm/pagewalk.c:240 [inline]
 walk_pgd_range mm/pagewalk.c:277 [inline]
 __walk_page_range+0x981/0x1160 mm/pagewalk.c:379
 walk_page_range+0x131/0x300 mm/pagewalk.c:475
 madvise_pageout_page_range mm/madvise.c:562 [inline]
 madvise_pageout mm/madvise.c:599 [inline]
 madvise_vma_behavior mm/madvise.c:988 [inline]
 madvise_walk_vmas mm/madvise.c:1207 [inline]
 do_madvise+0xd11/0x1170 mm/madvise.c:1385
 __do_sys_madvise mm/madvise.c:1398 [inline]
 __se_sys_madvise mm/madvise.c:1396 [inline]
 __x64_sys_madvise+0x5d/0x70 mm/madvise.c:1396
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888124e2b530 of 8 bytes by task 13905 on cpu 1:
 shmem_recalc_inode mm/shmem.c:362 [inline]
 shmem_getpage_gfp+0xf1b/0x12c0 mm/shmem.c:1912
 shmem_fault+0xd1/0x3c0 mm/shmem.c:2080
 __do_fault mm/memory.c:3868 [inline]
 do_shared_fault mm/memory.c:4238 [inline]
 do_fault mm/memory.c:4316 [inline]
 handle_pte_fault mm/memory.c:4570 [inline]
 __handle_mm_fault mm/memory.c:4705 [inline]
 handle_mm_fault+0xc78/0x1590 mm/memory.c:4803
 do_user_addr_fault+0x617/0xb90 arch/x86/mm/fault.c:1397
 handle_page_fault arch/x86/mm/fault.c:1484 [inline]
 exc_page_fault+0x91/0x290 arch/x86/mm/fault.c:1540
 asm_exc_page_fault+0x1e/0x30
 copy_user_enhanced_fast_string+0xe/0x40
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
 _copy_to_user+0x77/0x90 lib/usercopy.c:33
 copy_to_user include/linux/uaccess.h:200 [inline]
 extract_crng_user drivers/char/random.c:1055 [inline]
 urandom_read_nowarn+0x199/0x350 drivers/char/random.c:1733
 __do_sys_getrandom drivers/char/random.c:1926 [inline]
 __se_sys_getrandom drivers/char/random.c:1901 [inline]
 __x64_sys_getrandom+0xd6/0x130 drivers/char/random.c:1901
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000866 -> 0x000000000000085f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13905 Comm: syz-executor.4 Not tainted 5.17.0-rc4-syzkaller-00069-ga3580ac9b7a3-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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