syzbot

loop1: detected capacity change from 0 to 4096
EXT4-fs (loop1): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none.
==================================================================
BUG: KCSAN: data-race in __writeback_single_inode / vfs_fsync_range

write to 0xffff8881261cf750 of 8 bytes by task 16048 on cpu 1:
 __writeback_single_inode+0x1f6/0x590 fs/fs-writeback.c:1634
 writeback_single_inode+0x126/0x490 fs/fs-writeback.c:1719
 sync_inode_metadata+0x52/0x70 fs/fs-writeback.c:2775
 ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline]
 ext4_sync_file+0x349/0x6d0 fs/ext4/fsync.c:170
 vfs_fsync_range+0x107/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2885 [inline]
 ext4_buffered_write_iter+0x398/0x3e0 fs/ext4/file.c:292
 ext4_file_write_iter+0x2bb/0x11b0
 do_iter_write+0x494/0x750 fs/read_write.c:861
 vfs_iter_write+0x4c/0x70 fs/read_write.c:902
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:931
 splice_direct_to_actor+0x305/0x620 fs/splice.c:886
 do_splice_direct+0xfb/0x180 fs/splice.c:974
 do_sendfile+0x3bf/0x910 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff8881261cf750 of 8 bytes by task 16041 on cpu 0:
 vfs_fsync_range+0x98/0x120 fs/sync.c:186
 generic_write_sync include/linux/fs.h:2885 [inline]
 ext4_buffered_write_iter+0x398/0x3e0 fs/ext4/file.c:292
 ext4_file_write_iter+0x2bb/0x11b0
 do_iter_write+0x494/0x750 fs/read_write.c:861
 vfs_iter_write+0x4c/0x70 fs/read_write.c:902
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:931
 splice_direct_to_actor+0x305/0x620 fs/splice.c:886
 do_splice_direct+0xfb/0x180 fs/splice.c:974
 do_sendfile+0x3bf/0x910 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000087 -> 0x0000000000000084

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16041 Comm: syz-executor.1 Tainted: G        W          6.2.0-rc3-syzkaller-00349-g97ec4d559d93-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
==================================================================