[moderation] [v9fs?] KCSAN: data-race in p9_conn_cancel / p9_read_work

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 741e9d668aa5 Merge tag 'scsi-misc' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10653bb9180000
kernel config: https://syzkaller.appspot.com/x/.config?x=f6807a59ab85347d
dashboard link: https://syzkaller.appspot.com/bug?extid=67e532110593813fdc58
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [asma...@codewreck.org eri...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org linu...@crudebyte.com lu...@ionkov.net v9...@lists.linux.dev]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7991c18f9658/disk-741e9d66.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ee798a879279/vmlinux-741e9d66.xz
kernel image: https://storage.googleapis.com/syzbot-assets/76910846e995/bzImage-741e9d66.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+67e532...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in p9_conn_cancel / p9_read_work

write to 0xffff8881267b9e28 of 4 bytes by task 3173 on cpu 0:
p9_conn_cancel+0x89/0x400 net/9p/trans_fd.c:200
p9_write_work+0x3ac/0x750 net/9p/trans_fd.c:523
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
worker_thread+0x526/0x730 kernel/workqueue.c:3416
kthread+0x1d1/0x210 kernel/kthread.c:388
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

read to 0xffff8881267b9e28 of 4 bytes by task 5724 on cpu 1:
p9_read_work+0x34/0x8d0 net/9p/trans_fd.c:287
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
worker_thread+0x526/0x730 kernel/workqueue.c:3416
kthread+0x1d1/0x210 kernel/kthread.c:388
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

value changed: 0x00000000 -> 0xffffff91

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5724 Comm: kworker/1:7 Tainted: G W 6.8.0-syzkaller-11339-g741e9d668aa5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: events p9_read_work
==================================================================


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[syzbot]

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