From: Andrew Morton <akpm@linux-foundation.org>
To: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <dhillf@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org
Subject: Re: [PATCH] mm/huge_memory: Clean up typo when copying user highpage
Date: Wed, 12 Oct 2011 13:42:24 -0700 [thread overview]
Message-ID: <20111012134224.786191ac.akpm@linux-foundation.org> (raw)
In-Reply-To: <20111012175148.GA27460@redhat.com>
On Wed, 12 Oct 2011 19:51:48 +0200
Andrea Arcangeli <aarcange@redhat.com> wrote:
> On Wed, Oct 12, 2011 at 10:39:36PM +0800, Hillf Danton wrote:
> > Hi Andrea
> >
> > When copying user highpage, the PAGE_SHIFT in the third parameter is a typo,
> > I think, and is replaced with PAGE_SIZE.
>
> That looks correct. I wonder how it was not noticed yet. Because it
> can't go out of bound, it didn't risk to crash the kernel and it didn't
> not risk to expose random data to the cowing task. So it shouldn't
> have security implications as far as I can tell, but the app could
> malfunction and crash (userland corruption only).
Which architectures care about the copy_user_page() `vaddr' argument?
mips, perhaps? I suspect the intersection between those architectures
and archs-which-implement-hugepages is the empty set.
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@linux-foundation.org>
To: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <dhillf@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org
Subject: Re: [PATCH] mm/huge_memory: Clean up typo when copying user highpage
Date: Wed, 12 Oct 2011 13:42:24 -0700 [thread overview]
Message-ID: <20111012134224.786191ac.akpm@linux-foundation.org> (raw)
In-Reply-To: <20111012175148.GA27460@redhat.com>
On Wed, 12 Oct 2011 19:51:48 +0200
Andrea Arcangeli <aarcange@redhat.com> wrote:
> On Wed, Oct 12, 2011 at 10:39:36PM +0800, Hillf Danton wrote:
> > Hi Andrea
> >
> > When copying user highpage, the PAGE_SHIFT in the third parameter is a typo,
> > I think, and is replaced with PAGE_SIZE.
>
> That looks correct. I wonder how it was not noticed yet. Because it
> can't go out of bound, it didn't risk to crash the kernel and it didn't
> not risk to expose random data to the cowing task. So it shouldn't
> have security implications as far as I can tell, but the app could
> malfunction and crash (userland corruption only).
Which architectures care about the copy_user_page() `vaddr' argument?
mips, perhaps? I suspect the intersection between those architectures
and archs-which-implement-hugepages is the empty set.
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next prev parent reply other threads:[~2011-10-12 20:42 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-12 14:39 [PATCH] mm/huge_memory: Clean up typo when copying user highpage Hillf Danton
2011-10-12 14:39 ` Hillf Danton
2011-10-12 15:56 ` Johannes Weiner
2011-10-12 15:56 ` Johannes Weiner
2011-10-12 17:51 ` Andrea Arcangeli
2011-10-12 17:51 ` Andrea Arcangeli
2011-10-12 20:42 ` Andrew Morton [this message]
2011-10-12 20:42 ` Andrew Morton
2011-10-12 22:24 ` Andrea Arcangeli
2011-10-12 22:24 ` Andrea Arcangeli
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