loop7: detected capacity change from 0 to 128
==================================================================
BUG: KCSAN: data-race in __xa_clear_mark / xas_find_marked

read-write to 0xffff8881187ed470 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:2094
 __folio_end_writeback+0x177/0x470 mm/page-writeback.c:3047
 folio_end_writeback+0xb6/0x3a0 mm/filemap.c:1648
 mpage_write_end_io+0x274/0x390 fs/mpage.c:65
 bio_endio+0x34f/0x3f0 block/bio.c:1551
 blk_update_request+0x339/0x730 block/blk-mq.c:983
 blk_mq_end_request+0x26/0x50 block/blk-mq.c:1145
 lo_complete_rq+0x98/0x140 drivers/block/loop.c:304
 blk_complete_reqs block/blk-mq.c:1220 [inline]
 blk_done_softirq+0x74/0xb0 block/blk-mq.c:1225
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 run_ksoftirqd+0x1c/0x30 kernel/softirq.c:968
 smpboot_thread_fn+0x328/0x530 kernel/smpboot.c:164
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff8881187ed470 of 8 bytes by task 12789 on cpu 1:
 xas_find_chunk include/linux/xarray.h:1746 [inline]
 xas_find_marked+0x218/0x620 lib/xarray.c:1510
 find_get_entry+0x5d/0x380 mm/filemap.c:2027
 filemap_get_folios_tag+0x13b/0x210 mm/filemap.c:2295
 __filemap_fdatawait_range mm/filemap.c:530 [inline]
 filemap_write_and_wait_range+0x1d3/0x340 mm/filemap.c:700
 kiocb_write_and_wait mm/filemap.c:2792 [inline]
 generic_file_read_iter+0x101/0x330 mm/filemap.c:2866
 aio_read+0x1da/0x2e0 fs/aio.c:1602
 __io_submit_one fs/aio.c:-1 [inline]
 io_submit_one+0xaad/0x11b0 fs/aio.c:2052
 __do_sys_io_submit fs/aio.c:2111 [inline]
 __se_sys_io_submit+0xfb/0x280 fs/aio.c:2081
 __x64_sys_io_submit+0x43/0x50 fs/aio.c:2081
 x64_sys_call+0xfc4/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:210
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xfffffc0000000000 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 12789 Comm: syz.7.16775 Tainted: G        W           6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
==================================================================
bio_check_eod: 73 callbacks suppressed
syz.7.16775: attempt to access beyond end of device
loop7: rw=0, sector=121, nr_sectors = 920 limit=128