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BUG: KCSAN: data-race in __xa_clear_mark / xas_find_marked

read-write to 0xffff888107743fd8 of 8 bytes by interrupt on cpu 0:
 instrument_read_write include/linux/instrumented.h:55 [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:2100
 __folio_end_writeback+0xf4/0x360 mm/page-writeback.c:2992
 folio_end_writeback_no_dropbehind+0x6d/0x1d0 mm/filemap.c:1661
 folio_end_writeback+0x1c/0x70 mm/filemap.c:1687
 end_buffer_async_write+0x156/0x1f0 fs/buffer.c:420
 end_bio_bh_io_sync+0x79/0xa0 fs/buffer.c:2777
 bio_endio+0x37a/0x410 block/bio.c:1790
 blk_update_request+0x338/0x730 block/blk-mq.c:1019
 blk_mq_end_request+0x26/0x50 block/blk-mq.c:1181
 lo_complete_rq+0x98/0x140 drivers/block/loop.c:314
 blk_complete_reqs block/blk-mq.c:1256 [inline]
 blk_done_softirq+0x77/0xb0 block/blk-mq.c:1261
 handle_softirqs+0xb9/0x280 kernel/softirq.c:622
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:1063
 smpboot_thread_fn+0x32a/0x510 kernel/smpboot.c:160
 kthread+0x22a/0x280 kernel/kthread.c:467
 ret_from_fork+0x148/0x280 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

read to 0xffff888107743fd8 of 8 bytes by task 3542 on cpu 1:
 xas_find_chunk include/linux/xarray.h:1752 [inline]
 xas_find_marked+0x213/0x620 lib/xarray.c:1510
 find_get_entry mm/filemap.c:2064 [inline]
 filemap_get_folios_tag+0xfa/0x510 mm/filemap.c:2332
 __filemap_fdatawait_range mm/filemap.c:523 [inline]
 filemap_write_and_wait_range+0x1f5/0x370 mm/filemap.c:692
 filemap_write_and_wait include/linux/pagemap.h:65 [inline]
 sync_blockdev block/bdev.c:276 [inline]
 bdev_release+0xeb/0x3d0 block/bdev.c:1142
 blkdev_release+0x15/0x20 block/fops.c:706
 __fput+0x29b/0x650 fs/file_table.c:469
 fput_close_sync+0xad/0x190 fs/file_table.c:574
 __do_sys_close fs/open.c:1509 [inline]
 __se_sys_close fs/open.c:1494 [inline]
 __x64_sys_close+0x55/0xf0 fs/open.c:1494
 x64_sys_call+0x2c25/0x3000 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000003 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3542 Comm: udevd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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udevd[3542]: inotify_add_watch(7, /dev/loop5p2, 10) failed: No such file or directory