[moderation] [v9fs?] KCSAN: data-race in p9_conn_cancel / p9_read_work (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 96e09b8f8166 Merge tag 'platform-drivers-x86-v6.10-3' of g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=119479ce980000
kernel config: https://syzkaller.appspot.com/x/.config?x=8c00b51a1d411353
dashboard link: https://syzkaller.appspot.com/bug?extid=a93db7f68817fbc637f8
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 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/1af3d5512e37/disk-96e09b8f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fc46480a4a19/vmlinux-96e09b8f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/145364f0ab4e/bzImage-96e09b8f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a93db7...@syzkaller.appspotmail.com

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

write to 0xffff888148981428 of 4 bytes by task 4813 on cpu 1:
p9_conn_cancel+0x89/0x400 net/9p/trans_fd.c:199
p9_write_work+0x3ac/0x750 net/9p/trans_fd.c:522
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312
worker_thread+0x526/0x730 kernel/workqueue.c:3393
kthread+0x1d1/0x210 kernel/kthread.c:389
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffff888148981428 of 4 bytes by task 4823 on cpu 0:
p9_read_work+0x34/0x8d0 net/9p/trans_fd.c:286
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312
worker_thread+0x526/0x730 kernel/workqueue.c:3393
kthread+0x1d1/0x210 kernel/kthread.c:389
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x00000000 -> 0xffffffe0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4823 Comm: kworker/0:8 Not tainted 6.10.0-rc2-syzkaller-00269-g96e09b8f8166 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: events p9_read_work
==================================================================


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