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BUG: KCSAN: data-race in __xa_clear_mark / xas_find_marked

read-write to 0xffff88810bcd9228 of 8 bytes by interrupt on cpu 1:
 instrument_read_write include/linux/instrumented.h:56 [inline]
 __instrument_read_write_bitop include/asm-generic/bitops/instrumented-non-atomic.h:84 [inline]
 ___test_and_clear_bit include/asm-generic/bitops/instrumented-non-atomic.h:114 [inline]
 node_clear_mark lib/xarray.c:102 [inline]
 xas_clear_mark lib/xarray.c:922 [inline]
 __xa_clear_mark+0xf5/0x1e0 lib/xarray.c:2103
 __folio_end_writeback+0xe7/0x530 mm/page-writeback.c:2965
 folio_end_writeback_no_dropbehind+0x6d/0x200 mm/filemap.c:1671
 folio_end_writeback+0x72/0x110 mm/filemap.c:1710
 bh_end_async_write+0x18b/0x230 fs/buffer.c:430
 bio_endio+0x390/0x570 block/bio.c:1908
 blk_update_request+0x33a/0x710 block/blk-mq.c:1029
 scsi_end_request+0x4b/0x4c0 drivers/scsi/scsi_lib.c:671
 scsi_io_completion+0x7f/0x1d0 drivers/scsi/scsi_lib.c:1125
 scsi_finish_command+0x1c7/0x1e0 drivers/scsi/scsi.c:198
 scsi_complete+0x12c/0x4a0 drivers/scsi/scsi_lib.c:1604
 blk_complete_reqs block/blk-mq.c:1235 [inline]
 blk_done_softirq+0x77/0xb0 block/blk-mq.c:1240
 handle_softirqs+0x109/0x310 kernel/softirq.c:669
 __do_softirq kernel/softirq.c:703 [inline]
 invoke_softirq kernel/softirq.c:542 [inline]
 __irq_exit_rcu+0x40/0xf0 kernel/softirq.c:786
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0x74/0x80 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
 check_kcov_mode kernel/kcov.c:179 [inline]
 __sanitizer_cov_trace_pc+0x49/0x80 kernel/kcov.c:223
 percpu_counter_add_batch+0x1d/0x120 lib/percpu_counter.c:94
 percpu_counter_add include/linux/percpu_counter.h:71 [inline]
 add_mm_counter include/linux/mm.h:3622 [inline]
 add_mm_rss_vec mm/memory.c:492 [inline]
 copy_pte_range mm/memory.c:1391 [inline]
 copy_pmd_range mm/memory.c:1453 [inline]
 copy_pud_range mm/memory.c:1490 [inline]
 copy_p4d_range mm/memory.c:1514 [inline]
 copy_page_range+0x2a95/0x3320 mm/memory.c:1600
 dup_mmap+0x874/0x1120 mm/mmap.c:1819
 dup_mm kernel/fork.c:1542 [inline]
 copy_mm+0xf5/0x340 kernel/fork.c:1594
 copy_process+0x10e9/0x23f0 kernel/fork.c:2320
 kernel_clone+0x1c0/0x5f0 kernel/fork.c:2784
 __do_sys_clone kernel/fork.c:2926 [inline]
 __se_sys_clone kernel/fork.c:2910 [inline]
 __x64_sys_clone+0x143/0x180 kernel/fork.c:2910
 x64_sys_call+0x2479/0x2550 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810bcd9228 of 8 bytes by task 4825 on cpu 0:
 xas_find_chunk include/linux/xarray.h:1752 [inline]
 xas_find_marked+0x211/0x650 lib/xarray.c:1513
 find_get_entry mm/filemap.c:2105 [inline]
 filemap_get_folios_tag+0xf7/0x400 mm/filemap.c:2371
 __filemap_fdatawait_range mm/filemap.c:523 [inline]
 filemap_write_and_wait_range+0x1f5/0x370 mm/filemap.c:692
 filemap_invalidate_pages+0xd3/0x1e0 mm/filemap.c:2946
 kiocb_invalidate_pages+0x6e/0x80 mm/filemap.c:2965
 blkdev_direct_write+0x30/0x100 block/fops.c:704
 blkdev_write_iter+0x3ad/0x530 block/fops.c:797
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x57a/0x990 fs/read_write.c:687
 ksys_write+0xdc/0x1a0 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:747
 x64_sys_call+0x154e/0x2550 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xfffffffffffffc00 -> 0xffffffffffe00000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4825 Comm: syz.1.485 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
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