[moderation] [serial?] KCSAN: data-race in __tty_hangup / do_dentry_open (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4854cf9c61d0 Merge tag 'mips-fixes_6.8_1' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11411b30180000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bd33f45956bbc2
dashboard link: https://syzkaller.appspot.com/bug?extid=7e8e098ebb940693c013
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/e44f160651d1/disk-4854cf9c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f6a2062d07e6/vmlinux-4854cf9c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3d179908ef3c/bzImage-4854cf9c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7e8e09...@syzkaller.appspotmail.com

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

write to 0xffff88813492d5b0 of 8 bytes by task 7152 on cpu 0:
__tty_hangup+0x1e8/0x530 drivers/tty/tty_io.c:621
tty_vhangup drivers/tty/tty_io.c:700 [inline]
tty_ioctl+0x60a/0xbc0 drivers/tty/tty_io.c:2743
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xcf/0x140 fs/ioctl.c:857
__x64_sys_ioctl+0x43/0x50 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88813492d5b0 of 8 bytes by task 7148 on cpu 1:
do_dentry_open+0x6ad/0xbd0 fs/open.c:959
vfs_open+0x4a/0x50 fs/open.c:1087
do_open fs/namei.c:3641 [inline]
path_openat+0x1819/0x1d30 fs/namei.c:3798
do_filp_open+0xf6/0x200 fs/namei.c:3825
do_sys_openat2+0xab/0x110 fs/open.c:1404
do_sys_open fs/open.c:1419 [inline]
__do_sys_openat fs/open.c:1435 [inline]
__se_sys_openat fs/open.c:1430 [inline]
__x64_sys_openat+0xf3/0x120 fs/open.c:1430
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0xffffffff850974a8 -> 0xffffffff85097340

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7148 Comm: syz-executor.4 Not tainted 6.8.0-rc1-syzkaller-00385-g4854cf9c61d0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.