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From: Steven Rostedt <rostedt@goodmis.org>
To: madhu.subbaiah@wipro.com
Cc: linux-kernel@vger.kernel.org
Subject: Re: select() for delay.
Date: Mon, 24 Oct 2005 09:18:54 -0400	[thread overview]
Message-ID: <1130159934.7804.15.camel@localhost.localdomain> (raw)
In-Reply-To: <EE111F112BBFF24FB11DB557FA2E5BF301992F02@BLR-EC-MBX02.wipro.com>

Hi Maduhu,

On Mon, 2005-10-24 at 16:25 +0530, madhu.subbaiah@wipro.com wrote:

> +                        put_user(sec, &tvp->tv_sec);
> +                        put_user(usec, &tvp->tv_usec);

I won't comment on the rest of the patch, but this part is definitely
wrong.  The pointer tvp is a user space address and once you dereference
that pointer to get to tv_sec, you can have a fault, which might
segfault the processes.

What you really want is something like:

{
	timeval tv;

	tv.tv_sec = sec;
	tv.tv_usec = usec;
	copy_to_user(tvp, &tv, sizeof(tv));
}

-- Steve



  reply	other threads:[~2005-10-24 13:19 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-10-24 10:55 select() for delay madhu.subbaiah
2005-10-24 13:18 ` Steven Rostedt [this message]
2005-10-24 13:27   ` Arjan van de Ven
2005-10-24 13:37     ` Steven Rostedt
2005-10-25  6:26     ` Madhu K.S.
2005-10-30 19:06 ` Arnd Bergmann
2005-10-30 19:12   ` Arjan van de Ven
2005-10-31 15:46   ` Christopher Friesen

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