[moderation] [serial?] KCSAN: data-race in __tty_hangup / io_arm_poll_handler

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9bacdd8996c7 Merge tag 'for-6.7-rc1-tag' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1731631f680000
kernel config: https://syzkaller.appspot.com/x/.config?x=a91f789b98394377
dashboard link: https://syzkaller.appspot.com/bug?extid=74c859f8d6a768d0c7a4
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [gre...@linuxfoundation.org jiri...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/be70757ec048/disk-9bacdd89.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/45e8c725b4dc/vmlinux-9bacdd89.xz
kernel image: https://storage.googleapis.com/syzbot-assets/82e551f976a9/bzImage-9bacdd89.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+74c859...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __tty_hangup / io_arm_poll_handler

write to 0xffff88814c1ab5b0 of 8 bytes by task 28997 on cpu 0:
__tty_hangup+0x1e8/0x530 drivers/tty/tty_io.c:621
tty_vhangup+0x17/0x20 drivers/tty/tty_io.c:700
pty_close+0x262/0x280 drivers/tty/pty.c:79
tty_release+0x204/0x930 drivers/tty/tty_io.c:1756
__fput+0x299/0x630 fs/file_table.c:394
____fput+0x15/0x20 fs/file_table.c:422
task_work_run+0x135/0x1a0 kernel/task_work.c:180
get_signal+0xf04/0x10a0 kernel/signal.c:2680
arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:309
exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
do_syscall_64+0x50/0x110 arch/x86/entry/common.c:88
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88814c1ab5b0 of 8 bytes by task 29003 on cpu 1:
file_can_poll include/linux/poll.h:81 [inline]
io_arm_poll_handler+0xb5/0x580 io_uring/poll.c:709
io_queue_async+0x85/0x470 io_uring/io_uring.c:2048
io_queue_sqe io_uring/io_uring.c:2079 [inline]
io_req_task_submit+0x11c/0x130 io_uring/io_uring.c:1498
handle_tw_list io_uring/io_uring.c:1207 [inline]
tctx_task_work+0x1af/0x4c0 io_uring/io_uring.c:1299
task_work_run+0x135/0x1a0 kernel/task_work.c:180
get_signal+0xf04/0x10a0 kernel/signal.c:2680
arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:309
exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
do_syscall_64+0x50/0x110 arch/x86/entry/common.c:88
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0xffffffff84e96138 -> 0xffffffff84e95fd0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29003 Comm: syz-executor.3 Tainted: G W 6.7.0-rc1-syzkaller-00012-g9bacdd8996c7 #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.