Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262898AbUJ1Uwn (ORCPT ); Thu, 28 Oct 2004 16:52:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263006AbUJ1Uwm (ORCPT ); Thu, 28 Oct 2004 16:52:42 -0400 Received: from clock-tower.bc.nu ([81.2.110.250]:40868 "EHLO localhost.localdomain") by vger.kernel.org with ESMTP id S262898AbUJ1U1r (ORCPT ); Thu, 28 Oct 2004 16:27:47 -0400 Subject: Re: BUG REPORT: User/Kernel Pointer bug in sys_poll From: Alan Cox To: Andrew Morton Cc: Sorav Bansal , tacetan@yahoo.com, Linux Kernel Mailing List In-Reply-To: <20041028024839.6a1e1064.akpm@osdl.org> References: <20041028052218.52478.qmail@web50207.mail.yahoo.com> <20041028024839.6a1e1064.akpm@osdl.org> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1098991488.9557.35.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Thu, 28 Oct 2004 20:24:49 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 655 Lines: 15 On Iau, 2004-10-28 at 10:48, Andrew Morton wrote: > is safe. We know that the address is in the 0x00000000-0xbfffffff range by > the time we call __put_user(). And if the page at *addr it not writeable > the kernel will take a fault. > > So I see no hole. But I wouldn't have coded it that way... On x86 maybe. I think he's right in the sense that we may have a non x86 platform that this is not safe on. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/