loop2: detected capacity change from 0 to 128
==================================================================
BUG: KCSAN: data-race in xas_find_marked / xas_set_mark

read-write to 0xffff888106bb1478 of 8 bytes by task 22793 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_set_bit include/asm-generic/bitops/instrumented-non-atomic.h:99 [inline]
 node_set_mark lib/xarray.c:95 [inline]
 xas_set_mark+0x86/0x140 lib/xarray.c:885
 tag_pages_for_writeback+0xaa/0x2a0 mm/page-writeback.c:2350
 write_cache_pages+0x1ad/0x740 mm/page-writeback.c:2420
 mpage_writepages+0x72/0xe0 fs/mpage.c:672
 fat_writepages+0x24/0x30 fs/fat/inode.c:200
 do_writepages+0x1c2/0x340 mm/page-writeback.c:2553
 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:388
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 file_write_and_wait_range+0xf4/0x190 mm/filemap.c:779
 __generic_file_fsync+0x4c/0x140 fs/libfs.c:1438
 fat_file_fsync+0x4c/0x100 fs/fat/file.c:191
 vfs_fsync_range fs/sync.c:188 [inline]
 vfs_fsync fs/sync.c:202 [inline]
 do_fsync fs/sync.c:212 [inline]
 __do_sys_fdatasync fs/sync.c:225 [inline]
 __se_sys_fdatasync fs/sync.c:223 [inline]
 __x64_sys_fdatasync+0x84/0xd0 fs/sync.c:223
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888106bb1478 of 8 bytes by task 22792 on cpu 0:
 xas_find_chunk include/linux/xarray.h:1723 [inline]
 xas_find_marked+0x216/0x660 lib/xarray.c:1354
 find_get_entry+0x5d/0x290 mm/filemap.c:1961
 filemap_get_folios_tag+0x136/0x210 mm/filemap.c:2211
 write_cache_pages+0x20d/0x740 mm/page-writeback.c:2429
 mpage_writepages+0x72/0xe0 fs/mpage.c:672
 fat_writepages+0x24/0x30 fs/fat/inode.c:200
 do_writepages+0x1c2/0x340 mm/page-writeback.c:2553
 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:388
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 file_write_and_wait_range+0xf4/0x190 mm/filemap.c:779
 __generic_file_fsync+0x4c/0x140 fs/libfs.c:1438
 fat_file_fsync+0x4c/0x100 fs/fat/file.c:191
 vfs_fsync_range fs/sync.c:188 [inline]
 vfs_fsync fs/sync.c:202 [inline]
 do_fsync fs/sync.c:212 [inline]
 __do_sys_fdatasync fs/sync.c:225 [inline]
 __se_sys_fdatasync fs/sync.c:223 [inline]
 __x64_sys_fdatasync+0x84/0xd0 fs/sync.c:223
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0xffffffffffffffff -> 0xfffffffffffffff8

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 22792 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-00410-gc02197fc9076 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================
syz-executor.2: attempt to access beyond end of device
loop2: rw=524288, sector=209, nr_sectors = 144 limit=128
syz-executor.2: attempt to access beyond end of device
loop2: rw=0, sector=209, nr_sectors = 8 limit=128