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BUG: KCSAN: data-race in __xa_clear_mark / xas_find_marked

read-write to 0xffff8881072276b8 of 8 bytes by interrupt on cpu 1:
 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+0xf7/0x3b0 mm/page-writeback.c:2998
 folio_end_writeback_no_dropbehind+0x6d/0x1b0 mm/filemap.c:1668
 folio_end_writeback+0x1c/0x70 mm/filemap.c:1694
 ext4_finish_bio+0x459/0x8c0 fs/ext4/page-io.c:144
 ext4_end_bio+0x298/0x3b0 fs/ext4/page-io.c:-1
 bio_endio+0x37b/0x420 block/bio.c:1672
 blk_update_request+0x336/0x730 block/blk-mq.c:998
 scsi_end_request+0x53/0x4c0 drivers/scsi/scsi_lib.c:637
 scsi_io_completion+0x7f/0x200 drivers/scsi/scsi_lib.c:1078
 scsi_finish_command+0x1c7/0x1e0 drivers/scsi/scsi.c:198
 scsi_complete+0xc3/0x1e0 drivers/scsi/scsi_lib.c:1547
 blk_complete_reqs block/blk-mq.c:1235 [inline]
 blk_done_softirq+0x77/0xb0 block/blk-mq.c:1240
 handle_softirqs+0xb7/0x290 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x3a/0xc0 kernel/softirq.c:723
 common_interrupt+0x83/0x90 arch/x86/kernel/irq.c:318
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
 crng_make_state+0xf7/0x250 drivers/char/random.c:394
 _get_random_bytes+0x85/0x190 drivers/char/random.c:406
 get_random_bytes+0x1d/0x30 drivers/char/random.c:438
 eth_random_addr include/linux/etherdevice.h:238 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:771 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
 nsim_dev_trap_report_work+0x23c/0x630 drivers/net/netdevsim/dev.c:866
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x486/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff8881072276b8 of 8 bytes by task 9325 on cpu 0:
 xas_find_chunk include/linux/xarray.h:1752 [inline]
 xas_find_marked+0x218/0x620 lib/xarray.c:1510
 find_get_entry+0x5d/0x380 mm/filemap.c:2070
 filemap_get_folios_tag+0x13b/0x210 mm/filemap.c:2338
 __filemap_fdatawait_range mm/filemap.c:533 [inline]
 filemap_fdatawait_keep_errors+0x6c/0x180 mm/filemap.c:636
 wait_sb_inodes fs/fs-writeback.c:2754 [inline]
 sync_inodes_sb+0x39c/0x440 fs/fs-writeback.c:2876
 sync_inodes_one_sb+0x3d/0x50 fs/sync.c:77
 __iterate_supers+0x110/0x220 fs/super.c:923
 iterate_supers+0x1f/0x30 fs/super.c:938
 ksys_sync+0x5c/0xe0 fs/sync.c:102
 __ia32_sys_sync+0xe/0x20 fs/sync.c:113
 x64_sys_call+0x2d1f/0x3000 arch/x86/include/generated/asm/syscalls_64.h:163
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00e0000000000000 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 9325 Comm: syz.1.2609 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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