EXT4-fs (loop1): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
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BUG: KCSAN: data-race in file_write_and_wait_range / xas_set_mark

write to 0xffff8881073c5ecc of 4 bytes by task 5975 on cpu 1:
 xa_mark_set lib/xarray.c:71 [inline]
 xas_set_mark+0x12b/0x140 lib/xarray.c:900
 __folio_start_writeback+0x16b/0x370 mm/page-writeback.c:3013
 ext4_bio_write_folio+0x5a2/0xa10 fs/ext4/page-io.c:544
 mpage_submit_folio fs/ext4/inode.c:2215 [inline]
 mpage_process_page_bufs+0x484/0x5e0 fs/ext4/inode.c:2322
 mpage_prepare_extent_to_map+0x836/0xc90 fs/ext4/inode.c:2870
 ext4_do_writepages+0xa69/0x2740 fs/ext4/inode.c:3070
 ext4_writepages+0x18c/0x300 fs/ext4/inode.c:3166
 do_writepages+0x1b9/0x300 mm/page-writeback.c:2562
 filemap_writeback mm/filemap.c:386 [inline]
 filemap_fdatawrite_range mm/filemap.c:411 [inline]
 file_write_and_wait_range+0x186/0x300 mm/filemap.c:785
 ext4_sync_file+0x114/0x5c0 fs/ext4/fsync.c:145
 vfs_fsync_range+0xc5/0xe0 fs/sync.c:186
 generic_write_sync include/linux/fs.h:2698 [inline]
 ext4_buffered_write_iter+0x518/0x580 fs/ext4/file.c:378
 ext4_file_write_iter+0x36e/0x1020 fs/ext4/file.c:-1
 iter_file_splice_write+0x6a6/0xa80 fs/splice.c:660
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0x153/0x270 fs/splice.c:1114
 splice_direct_to_actor+0x2f5/0x680 fs/splice.c:1023
 do_splice_direct_actor fs/splice.c:1157 [inline]
 do_splice_direct+0x119/0x1a0 fs/splice.c:1183
 do_sendfile+0x37d/0x640 fs/read_write.c:1351
 __do_sys_sendfile64 fs/read_write.c:1412 [inline]
 __se_sys_sendfile64 fs/read_write.c:1398 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1398
 x64_sys_call+0x1015/0x2550 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x116/0x380 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881073c5ecc of 4 bytes by task 5970 on cpu 0:
 xa_marked include/linux/xarray.h:424 [inline]
 mapping_tagged include/linux/fs.h:503 [inline]
 filemap_writeback mm/filemap.c:382 [inline]
 filemap_fdatawrite_range mm/filemap.c:411 [inline]
 file_write_and_wait_range+0x139/0x300 mm/filemap.c:785
 ext4_sync_file+0x114/0x5c0 fs/ext4/fsync.c:145
 vfs_fsync_range+0xc5/0xe0 fs/sync.c:186
 generic_write_sync include/linux/fs.h:2698 [inline]
 ext4_buffered_write_iter+0x518/0x580 fs/ext4/file.c:378
 ext4_file_write_iter+0x36e/0x1020 fs/ext4/file.c:-1
 iter_file_splice_write+0x6a6/0xa80 fs/splice.c:660
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0x153/0x270 fs/splice.c:1114
 splice_direct_to_actor+0x2f5/0x680 fs/splice.c:1023
 do_splice_direct_actor fs/splice.c:1157 [inline]
 do_splice_direct+0x119/0x1a0 fs/splice.c:1183
 do_sendfile+0x37d/0x640 fs/read_write.c:1351
 __do_sys_sendfile64 fs/read_write.c:1412 [inline]
 __se_sys_sendfile64 fs/read_write.c:1398 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1398
 x64_sys_call+0x1015/0x2550 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x116/0x380 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x05000021 -> 0x02000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 5970 Comm: syz.1.633 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
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