[moderation] [serial?] KCSAN: data-race in n_tty_check_unthrottle / n_tty_receive_buf_common (11)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: afdab700f65e Merge tag 'bitmap-6.11-rc' of https://github...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1204357d980000
kernel config: https://syzkaller.appspot.com/x/.config?x=cb57e6ebf675f9d2
dashboard link: https://syzkaller.appspot.com/bug?extid=bd604efc607d61854e34
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/f79e4c957ffe/disk-afdab700.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/17c1786c8ecc/vmlinux-afdab700.xz
kernel image: https://storage.googleapis.com/syzbot-assets/172295f7cb0f/bzImage-afdab700.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bd604e...@syzkaller.appspotmail.com

BUG: KCSAN: data-race in n_tty_check_unthrottle / n_tty_receive_buf_common

write to 0xffff88811d2025dc of 4 bytes by task 12388 on cpu 0:
tty_set_flow_change drivers/tty/tty.h:59 [inline]
n_tty_check_unthrottle+0xd7/0x1c0 drivers/tty/n_tty.c:280
n_tty_read+0xf0b/0x11d0 drivers/tty/n_tty.c:2312
iterate_tty_read drivers/tty/tty_io.c:862 [inline]
tty_read+0x15b/0x480 drivers/tty/tty_io.c:937
new_sync_read fs/read_write.c:395 [inline]
vfs_read+0x5e9/0x6e0 fs/read_write.c:476
ksys_read+0xeb/0x1b0 fs/read_write.c:619
__do_sys_read fs/read_write.c:629 [inline]
__se_sys_read fs/read_write.c:627 [inline]
__x64_sys_read+0x42/0x50 fs/read_write.c:627
x64_sys_call+0x27d3/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:1
__x64_sys_ioctl+0x43/0x50 fs/ioctl.c:893



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[syzbot]

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