[moderation] [fs?] KCSAN: data-race in iput / writeback_sb_inodes (11)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 90d35da658da Linux 6.8-rc7
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=139d8b32180000
kernel config: https://syzkaller.appspot.com/x/.config?x=f10ff55d327ef698
dashboard link: https://syzkaller.appspot.com/bug?extid=89dd4fb9e93bd7bd586b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [bra...@kernel.org ja...@suse.cz linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/db68fe219e77/disk-90d35da6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/feb8e6632739/vmlinux-90d35da6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0c6e98b6523c/bzImage-90d35da6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+89dd4f...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in iput / writeback_sb_inodes

write to 0xffff8881066e41c0 of 8 bytes by task 17323 on cpu 0:
writeback_sb_inodes+0x2da/0xad0 fs/fs-writeback.c:1905
wb_writeback+0x252/0x6e0 fs/fs-writeback.c:2092
wb_do_writeback fs/fs-writeback.c:2239 [inline]
wb_workfn+0x1a8/0x8d0 fs/fs-writeback.c:2279
process_one_work kernel/workqueue.c:2633 [inline]
process_scheduled_works+0x5b8/0xa40 kernel/workqueue.c:2706
worker_thread+0x525/0x730 kernel/workqueue.c:2787
kthread+0x1d7/0x210 kernel/kthread.c:388
ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:243

read to 0xffff8881066e41c0 of 8 bytes by task 20474 on cpu 1:
iput+0x32/0x5c0 fs/inode.c:1755
dentry_unlink_inode+0x22a/0x240 fs/dcache.c:400
d_delete+0x76/0xf0 fs/dcache.c:2389
d_delete_notify include/linux/fsnotify.h:299 [inline]
vfs_rmdir+0x1a0/0x2f0 fs/namei.c:4222
do_rmdir+0x194/0x320 fs/namei.c:4268
__do_sys_unlinkat fs/namei.c:4444 [inline]
__se_sys_unlinkat fs/namei.c:4438 [inline]
__x64_sys_unlinkat+0xa4/0xb0 fs/namei.c:4438
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000020001 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 20474 Comm: syz-executor.4 Not tainted 6.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================


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[syzbot]

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