From: David Woodhouse <dwmw2@infradead.org>
To: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Ingo Molnar <mingo@elte.hu>, "Zhao, Yu" <yu.zhao@intel.com>,
lkml <linux-kernel@vger.kernel.org>,
iommu <iommu@lists.linux-foundation.org>
Subject: Re: [PATCH] Intel-IOMMU Alignment Issue in dma_pte_clear_range()
Date: Mon, 06 Apr 2009 14:48:22 -0700 [thread overview]
Message-ID: <1239054502.22733.102.camel@macbook.infradead.org> (raw)
In-Reply-To: <20090406182149.GA28529@linux-os.sc.intel.com>
On Mon, 2009-04-06 at 11:21 -0700, Fenghua Yu wrote:
> This issue was pointed out by Linus.
>
> In dma_pte_clear_range() in intel-iommu.c
>
> start = PAGE_ALIGN(start);
> end &= PAGE_MASK;
> npages = (end - start) / VTD_PAGE_SIZE;
>
> In partial page case, start could be bigger than end and npages will be
> negative.
>
> Currently the issue doesn't show up as a real bug in testing because start and
> end have been aligned to page boundary already by all callers. So the issue has
> been hiden. But it is dangerous programming practice.
>
> The following patch fixes the issue. It's applied on iommu-2.6.git tree.
>
> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Applied to git://git.infradead.org/iommu-2.6.git; thanks.
--
David Woodhouse Open Source Technology Centre
David.Woodhouse@intel.com Intel Corporation
prev parent reply other threads:[~2009-04-06 21:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1238507922.3294.35.camel@macbook.infradead.org>
[not found] ` <alpine.LFD.2.00.0904031140520.19690@localhost.localdomain>
[not found] ` <20090403191923.GA7772@linux-os.sc.intel.com>
2009-04-06 18:21 ` [PATCH] Intel-IOMMU Alignment Issue in dma_pte_clear_range() Fenghua Yu
2009-04-06 21:48 ` David Woodhouse [this message]
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