[moderation] [exfat?] KCSAN: data-race in mark_buffer_dirty_inode / sync_mapping_buffers (10)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8379578b11d5 Merge tag 'for-v6.13-rc' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10ebd018580000
kernel config: https://syzkaller.appspot.com/x/.config?x=87d3cfca6847d1fa
dashboard link: https://syzkaller.appspot.com/bug?extid=5e328f304cc42e6396f2
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/8549493bfd32/disk-8379578b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5666e8d42121/vmlinux-8379578b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3783ada62a33/bzImage-8379578b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5e328f...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in mark_buffer_dirty_inode / sync_mapping_buffers

write to 0xffff888106ad71f8 of 8 bytes by task 5429 on cpu 1:
__remove_assoc_queue fs/buffer.c:514 [inline]
fsync_buffers_list fs/buffer.c:785 [inline]
sync_mapping_buffers+0x159/0x7c0 fs/buffer.c:575
fat_file_fsync+0xa7/0x100 fs/fat/file.c:195
vfs_fsync_range+0x116/0x130 fs/sync.c:187
generic_write_sync include/linux/fs.h:2904 [inline]
generic_file_write_iter+0x185/0x1c0 mm/filemap.c:4186
new_sync_write fs/read_write.c:586 [inline]
vfs_write+0x77f/0x920 fs/read_write.c:679
ksys_write+0xe8/0x1b0 fs/read_write.c:731
__do_sys_write fs/read_write.c:742 [inline]
__se_sys_write fs/read_write.c:739 [inline]
__x64_sys_write+0x42/0x50 fs/read_write.c:739
x64_sys_call+0x287e/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888106ad71f8 of 8 bytes by task 5444 on cpu 0:
mark_buffer_dirty_inode+0x96/0x1c0 fs/buffer.c:678
fat16_ent_put+0x4f/0x60 fs/fat/fatent.c:184
fat_free_clusters+0x2a6/0x7a0 fs/fat/fatent.c:597
fat_free fs/fat/file.c:376 [inline]
fat_truncate_blocks+0x4a8/0x530 fs/fat/file.c:394
fat_setattr+0x734/0x840 fs/fat/file.c:551
notify_change+0x85c/0x8e0 fs/attr.c:552
do_truncate+0x116/0x160 fs/open.c:65
handle_truncate fs/namei.c:3449 [inline]
do_open fs/namei.c:3832 [inline]
path_openat+0x1c03/0x1fa0 fs/namei.c:3987
do_filp_open+0x107/0x230 fs/namei.c:4014
do_sys_openat2+0xab/0x120 fs/open.c:1402
do_sys_open fs/open.c:1417 [inline]
__do_sys_open fs/open.c:1425 [inline]
__se_sys_open fs/open.c:1421 [inline]
__x64_sys_open+0xe6/0x110 fs/open.c:1421
x64_sys_call+0x13e1/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:3
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff888106b9f208 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 5444 Comm: syz.1.611 Not tainted 6.13.0-rc4-syzkaller-00069-g8379578b11d5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================


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[syzbot]

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