[moderation] [exfat?] KCSAN: data-race in vfs_fsync_range / writeback_single_inode (6)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 6bc40e44f1dd Merge tag 'ovl-fixes-6.7-rc2' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13006f2f680000
kernel config: https://syzkaller.appspot.com/x/.config?x=a91f789b98394377
dashboard link: https://syzkaller.appspot.com/bug?extid=026b10b52af7040b34d4
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [hiro...@mail.parknet.co.jp linki...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org sj155...@samsung.com]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4c54159bb579/disk-6bc40e44.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3a252c242f68/vmlinux-6bc40e44.xz
kernel image: https://storage.googleapis.com/syzbot-assets/235f427df017/bzImage-6bc40e44.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+026b10...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in vfs_fsync_range / writeback_single_inode

write to 0xffff888107ddbdd0 of 8 bytes by task 565 on cpu 1:
writeback_single_inode+0x10e/0x4a0 fs/fs-writeback.c:1743
sync_inode_metadata+0x56/0x80 fs/fs-writeback.c:2808
__generic_file_fsync+0xf9/0x140 fs/libfs.c:1451
fat_file_fsync+0x4c/0x100 fs/fat/file.c:191
vfs_fsync_range+0x111/0x120 fs/sync.c:188
generic_write_sync include/linux/fs.h:2653 [inline]
generic_file_write_iter+0x191/0x1c0 mm/filemap.c:4043
do_iter_write+0x4ad/0x770 fs/read_write.c:860
vfs_iter_write+0x56/0x70 fs/read_write.c:901
iter_file_splice_write+0x462/0x7e0 fs/splice.c:736
do_splice_from fs/splice.c:933 [inline]
direct_splice_actor+0x8a/0xb0 fs/splice.c:1142
splice_direct_to_actor+0x31d/0x690 fs/splice.c:1088
do_splice_direct+0x10d/0x190 fs/splice.c:1194
do_sendfile+0x3c4/0x980 fs/read_write.c:1254
__do_sys_sendfile64 fs/read_write.c:1322 [inline]
__se_sys_sendfile64 fs/read_write.c:1308 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888107ddbdd0 of 8 bytes by task 462 on cpu 0:
vfs_fsync_range+0xa2/0x120 fs/sync.c:186
generic_write_sync include/linux/fs.h:2653 [inline]
generic_file_write_iter+0x191/0x1c0 mm/filemap.c:4043
do_iter_write+0x4ad/0x770 fs/read_write.c:860
vfs_iter_write+0x56/0x70 fs/read_write.c:901
iter_file_splice_write+0x462/0x7e0 fs/splice.c:736
do_splice_from fs/splice.c:933 [inline]
direct_splice_actor+0x8a/0xb0 fs/splice.c:1142
splice_direct_to_actor+0x31d/0x690 fs/splice.c:1088
do_splice_direct+0x10d/0x190 fs/splice.c:1194
do_sendfile+0x3c4/0x980 fs/read_write.c:1254
__do_sys_sendfile64 fs/read_write.c:1322 [inline]
__se_sys_sendfile64 fs/read_write.c:1308 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000000007 -> 0x0000000000000084

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 462 Comm: syz-executor.5 Not tainted 6.7.0-rc1-syzkaller-00139-g6bc40e44f1dd #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.