[moderation] [serial?] KCSAN: data-race in __tty_hangup / tty_hung_up_p (11)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 928a87efa423 Merge tag 'gfs2-v6.8-fix' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1678d7f1180000
kernel config: https://syzkaller.appspot.com/x/.config?x=aa27611f143168c9
dashboard link: https://syzkaller.appspot.com/bug?extid=20a8e5e71029bb3835cc
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/aaed8a3c54cc/disk-928a87ef.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4b57f9e2e4e0/vmlinux-928a87ef.xz
kernel image: https://storage.googleapis.com/syzbot-assets/dbcf18587d54/bzImage-928a87ef.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+20a8e5...@syzkaller.appspotmail.com

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

write to 0xffff88810d9b57b0 of 8 bytes by task 25896 on cpu 0:
__tty_hangup+0x1e8/0x540 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+0x20c/0x940 drivers/tty/tty_io.c:1760
__fput+0x2c1/0x660 fs/file_table.c:422
____fput+0x15/0x20 fs/file_table.c:450
task_work_run+0x13a/0x1a0 kernel/task_work.c:180
get_signal+0xeee/0x1080 kernel/signal.c:2683
arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
do_syscall_64+0xe2/0x1d0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x6d/0x75

read to 0xffff88810d9b57b0 of 8 bytes by task 25898 on cpu 1:
tty_hung_up_p+0x23/0x50 drivers/tty/tty_io.c:745
n_tty_read+0xa94/0x11d0 drivers/tty/n_tty.c:2247
iterate_tty_read drivers/tty/tty_io.c:862 [inline]
tty_read+0x15b/0x480 drivers/tty/tty_io.c:937
call_read_iter include/linux/fs.h:2102 [inline]
copy_splice_read+0x3a4/0x5d0 fs/splice.c:365
do_splice_read fs/splice.c:985 [inline]
splice_file_to_pipe+0x23d/0x390 fs/splice.c:1295
do_splice+0xc97/0x10e0 fs/splice.c:1379
__do_splice fs/splice.c:1436 [inline]
__do_sys_splice fs/splice.c:1652 [inline]
__se_sys_splice+0x24c/0x390 fs/splice.c:1634
__x64_sys_splice+0x78/0x90 fs/splice.c:1634
do_syscall_64+0xd3/0x1d0
entry_SYSCALL_64_after_hwframe+0x6d/0x75

value changed: 0xffffffff85299968 -> 0xffffffff85299800

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25898 Comm: syz-executor.4 Not tainted 6.9.0-rc1-syzkaller-00005-g928a87efa423 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
==================================================================


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