From: Jiri Slaby <jslaby@suse.cz>
To: Greg KH <greg@kroah.com>
Cc: gregkh@suse.de, jirislaby@gmail.com,
linux-kernel@vger.kernel.org, Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH v2 2/2] TTY: ntty, add one more sanity check
Date: Tue, 07 Jun 2011 18:57:50 +0200 [thread overview]
Message-ID: <4DEE588E.1050108@suse.cz> (raw)
In-Reply-To: <20110607164423.GA32575@kroah.com>
On 06/07/2011 06:44 PM, Greg KH wrote:
> On Sun, Jun 05, 2011 at 02:16:17PM +0200, Jiri Slaby wrote:
>> With the previous patch, we fixed another bug where read_buf was freed
>> while we still was in n_tty_read. We currently check whether read_buf
>> is NULL at the start of the function. Add one more check after we wake
>> up from waiting for input.
>>
>> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
>> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
>> ---
>> drivers/tty/n_tty.c | 1 +
>> 1 files changed, 1 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
>> index 95d0a9c..c62c856 100644
>> --- a/drivers/tty/n_tty.c
>> +++ b/drivers/tty/n_tty.c
>> @@ -1785,6 +1785,7 @@ do_it_again:
>> break;
>> }
>> timeout = schedule_timeout(timeout);
>> + BUG_ON(!tty->read_buf);
>
> So, if we ever hit this, what are we going to do with this crash?
>
> I really don't want to add more BUG_ON() calls to the kernel if at all
> possible. Or is it the case that we will crash if this case is true
> soon afterward anyway?
Yeah, it will crash something like 10 lines below. The pointer is
dereferenced there.
thanks,
--
js
suse labs
next prev parent reply other threads:[~2011-06-07 16:57 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1307106096-6461-1-git-send-email-jslaby@suse.cz>
2011-06-03 13:01 ` [PATCH 2/2] TTY: ntty, add one more sanoty check Jiri Slaby
2011-06-03 13:06 ` [PATCH 1/2] TTY: ldisc, do not close until there are readers Jiri Slaby
2011-06-03 21:52 ` Linus Torvalds
[not found] ` <1307276177-20957-1-git-send-email-jslaby@suse.cz>
2011-06-05 12:16 ` [PATCH v2 2/2] TTY: ntty, add one more sanity check Jiri Slaby
2011-06-07 16:44 ` Greg KH
2011-06-07 16:57 ` Jiri Slaby [this message]
2011-06-07 17:10 ` Greg KH
2011-06-07 17:20 ` Greg KH
2011-06-07 17:30 ` Jiri Slaby
2011-06-07 17:37 ` Greg KH
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