syzbot

loop0: rw=2049, sector=161, nr_sectors = 8 limit=128
syz.0.474: attempt to access beyond end of device
loop0: rw=2049, sector=177, nr_sectors = 8 limit=128
syz.0.474: attempt to access beyond end of device
loop0: rw=2049, sector=193, nr_sectors = 8 limit=128
syz.0.474: attempt to access beyond end of device
loop0: rw=2049, sector=209, nr_sectors = 8 limit=128
==================================================================
BUG: KCSAN: data-race in xas_find_marked / xas_init_marks

read-write to 0xffff888106f74910 of 8 bytes by task 7490 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]
 xas_init_marks+0x18a/0x320 lib/xarray.c:955
 xas_store+0x3cf/0xce0 lib/xarray.c:817
 page_cache_delete_batch mm/filemap.c:310 [inline]
 delete_from_page_cache_batch+0x30a/0x6f0 mm/filemap.c:332
 truncate_inode_pages_range+0x1b8/0x690 mm/truncate.c:380
 truncate_inode_pages mm/truncate.c:460 [inline]
 truncate_pagecache mm/truncate.c:769 [inline]
 truncate_setsize+0x9b/0xc0 mm/truncate.c:794
 fat_setattr+0x77b/0x8a0 fs/fat/file.c:550
 notify_change+0x806/0x890 fs/attr.c:552
 do_truncate fs/open.c:68 [inline]
 do_ftruncate+0x34b/0x450 fs/open.c:195
 do_sys_ftruncate fs/open.c:210 [inline]
 __do_sys_ftruncate fs/open.c:215 [inline]
 __se_sys_ftruncate fs/open.c:213 [inline]
 __x64_sys_ftruncate+0x68/0xc0 fs/open.c:213
 x64_sys_call+0xd65/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:78
 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

read to 0xffff888106f74910 of 8 bytes by task 7483 on cpu 1:
 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:2038
 filemap_get_folios_tag+0x13b/0x210 mm/filemap.c:2306
 writeback_get_folio mm/page-writeback.c:2463 [inline]
 writeback_iter+0x4bb/0x820 mm/page-writeback.c:2564
 mpage_writepages+0x718/0x1250 fs/mpage.c:663
 fat_writepages+0x24/0x30 fs/fat/inode.c:199
 do_writepages+0x1c6/0x310 mm/page-writeback.c:2636
 filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
 __filemap_fdatawrite_range mm/filemap.c:419 [inline]
 file_write_and_wait_range+0x156/0x2c0 mm/filemap.c:794
 __generic_file_fsync+0x46/0x140 fs/libfs.c:1526
 fat_file_fsync+0x49/0x100 fs/fat/file.c:191
 vfs_fsync_range fs/sync.c:187 [inline]
 vfs_fsync fs/sync.c:201 [inline]
 do_fsync fs/sync.c:212 [inline]
 __do_sys_fdatasync fs/sync.c:222 [inline]
 __se_sys_fdatasync fs/sync.c:220 [inline]
 __x64_sys_fdatasync+0x83/0xe0 fs/sync.c:220
 x64_sys_call+0x18f5/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:76
 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: 0x00000000000000fc -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 7483 Comm: syz.0.474 Not tainted 6.16.0-rc2-syzkaller-00087-g24770983ccfe #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================