KCSAN: data-race in __io_arm_poll_handler / __tty

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __io_arm_poll_handler / __tty_hangup serial				1	558d	543d	0/28	auto-obsoleted due to no activity on 2023/12/31 16:36

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BUG: KCSAN: data-race in __io_arm_poll_handler / __tty_hangup

write to 0xffff888125e869c8 of 8 bytes by task 4480 on cpu 1:
 __tty_hangup+0x1c2/0x510 drivers/tty/tty_io.c:615
 tty_vhangup+0x17/0x20 drivers/tty/tty_io.c:694
 pty_close+0x266/0x290 drivers/tty/pty.c:79
 tty_release+0x1fc/0xb10 drivers/tty/tty_io.c:1754
 __fput+0x29b/0x650 fs/file_table.c:465
 ____fput+0x1c/0x30 fs/file_table.c:493
 task_work_run+0x12e/0x1a0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xe4/0x100 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888125e869c8 of 8 bytes by task 4483 on cpu 0:
 vfs_poll include/linux/poll.h:80 [inline]
 __io_arm_poll_handler+0x1be/0xb70 io_uring/poll.c:583
 io_poll_add+0x69/0xe0 io_uring/poll.c:893
 __io_issue_sqe+0xfe/0x2e0 io_uring/io_uring.c:1730
 io_issue_sqe+0x53/0x970 io_uring/io_uring.c:1753
 io_queue_sqe io_uring/io_uring.c:1960 [inline]
 io_submit_sqe io_uring/io_uring.c:2216 [inline]
 io_submit_sqes+0x667/0xfd0 io_uring/io_uring.c:2329
 __do_sys_io_uring_enter io_uring/io_uring.c:3396 [inline]
 __se_sys_io_uring_enter+0x1c1/0x1b70 io_uring/io_uring.c:3330
 __x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3330
 x64_sys_call+0x28c8/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:427
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffffffff8589fd60 -> 0xffffffff8589fc50

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4483 Comm: syz.3.256 Not tainted 6.15.0-syzkaller-11802-g1af80d00e1e0 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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