From: Pavel Machek <pavel@ucw.cz>
To: linux-ia64@vger.kernel.org
Subject: Re: [RFC] prevent "dd if=/dev/mem" crash
Date: Sun, 19 Oct 2003 18:17:57 +0000 [thread overview]
Message-ID: <marc-linux-ia64-106689678007419@msgid-missing> (raw)
In-Reply-To: <marc-linux-ia64-106642876514553@msgid-missing>
Hi!
> > Old behavior:
> >
> > # dd if=/dev/mem of=/dev/null
> > <unrecoverable machine check>
>
> I recently fixed this for ia32 by changing copy_to_user() to not oops if
> the source address generated a fault. Similarly copy_from_user() returns
> an error if the destination generates a fault.
Are you sure this is not hiding real errors? If you pass wrong
kernel ptr to copy_*_user, it should oops, not mask error with
-EFAULT.
Maybe another copy_user_unsafe should be created?
Pavel
--
Pavel
Written on sharp zaurus, because my Velo1 broke. If you have Velo you don't need...
next prev parent reply other threads:[~2003-10-19 18:17 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-10-17 22:10 [RFC] prevent "dd if=/dev/mem" crash Bjorn Helgaas
2003-10-17 22:19 ` Luck, Tony
2003-10-17 22:23 ` Matt Mackall
2003-10-17 22:40 ` Andreas Schwab
2003-10-17 22:50 ` Andrew Morton
2003-10-17 23:25 ` Bjorn Helgaas
2003-10-17 23:55 ` Andrew Morton
2003-10-18 0:15 ` William Lee Irwin III
2003-10-18 0:21 ` David Mosberger
2003-10-18 0:49 ` Andrew Morton
2003-10-18 1:31 ` Matt Chapman
2003-10-18 1:41 ` Andrew Morton
2003-10-18 1:48 ` David Mosberger
2003-10-18 2:01 ` Andrew Morton
2003-10-18 2:01 ` Matt Chapman
2003-10-19 11:25 ` Eric W. Biederman
2003-10-19 18:17 ` Pavel Machek [this message]
2003-10-19 19:01 ` William Lee Irwin III
2003-10-20 15:17 ` Bjorn Helgaas
2003-10-20 17:42 ` Bjorn Helgaas
2003-10-20 18:48 ` David Mosberger
2003-10-23 8:33 ` Martin Pool
2003-10-23 9:31 ` Zoltan Menyhart
2003-10-23 21:05 ` Bjorn Helgaas
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