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Date: Wed, 19 Dec 2012 19:10:30 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Ilya Zykov <ilya@ilyx.ru>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Alan Cox <alan@linux.intel.com>, Jiri Slaby <jslaby@suse.cz>,
        Peter Hurley <peter@hurleysoftware.com>,
        Sasha Levin <levinsasha928@gmail.com>, linux-serial@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] tty: Fix unreasonable write toward closed pty.
Message-ID: <20121219191030.4ee20a1c@pyramind.ukuu.org.uk>
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> diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
> index a82b399..1ce1362 100644
> --- a/drivers/tty/pty.c
> +++ b/drivers/tty/pty.c
> @@ -116,6 +116,8 @@ static int pty_space(struct tty_struct *to)
>  
>  static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
>  {
> +	if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
> +		return -EIO;

The flag can change between the test and ny further code being executed ?

Alan