syzbot

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BUG: KCSAN: data-race in __io_queue_proc / io_poll_wake

write to 0xffff88817b26a428 of 8 bytes by task 1350 on cpu 1:
 io_poll_wake+0x1f9/0x3b0 io_uring/poll.c:416
 __wake_up_common kernel/sched/wait.c:108 [inline]
 __wake_up_common_lock kernel/sched/wait.c:125 [inline]
 __wake_up+0x66/0xb0 kernel/sched/wait.c:146
 __receive_buf drivers/tty/n_tty.c:1641 [inline]
 n_tty_receive_buf_common+0x735/0xbe0 drivers/tty/n_tty.c:1723
 n_tty_receive_buf2+0x33/0x40 drivers/tty/n_tty.c:1769
 tty_ldisc_receive_buf+0x66/0xf0 drivers/tty/tty_buffer.c:387
 tty_port_default_receive_buf+0x59/0x90 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:445 [inline]
 flush_to_ldisc+0x148/0x340 drivers/tty/tty_buffer.c:495
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff88817b26a428 of 8 bytes by task 15675 on cpu 0:
 __io_queue_proc+0x10a/0x280 io_uring/poll.c:469
 io_async_queue_proc+0x43/0x50 io_uring/poll.c:632
 poll_wait include/linux/poll.h:45 [inline]
 n_tty_poll+0x7a/0x450 drivers/tty/n_tty.c:2451
 tty_poll+0x79/0xf0 drivers/tty/tty_io.c:2199
 vfs_poll include/linux/poll.h:82 [inline]
 __io_arm_poll_handler+0x1ee/0xb70 io_uring/poll.c:579
 io_arm_apoll+0x2e8/0x420 io_uring/poll.c:687
 io_arm_poll_handler+0x131/0x160 io_uring/poll.c:716
 io_queue_async+0x25d/0x2d0 io_uring/io_uring.c:2055
 io_queue_sqe io_uring/io_uring.c:2081 [inline]
 io_req_task_submit+0xf6/0x100 io_uring/io_uring.c:1466
 io_poll_task_func+0x5fc/0x7c0 io_uring/poll.c:-1
 io_handle_tw_list+0xcc/0x1c0 io_uring/io_uring.c:1151
 tctx_task_work_run+0x6d/0x1a0 io_uring/io_uring.c:1216
 tctx_task_work+0x3f/0x80 io_uring/io_uring.c:1234
 task_work_run+0x131/0x1a0 kernel/task_work.c:227
 get_signal+0xe12/0xf70 kernel/signal.c:2807
 arch_do_signal_or_restart+0x96/0x440 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x77/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff888118df7208 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 15675 Comm: syz.7.16077 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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