From: Kees Cook <keescook@chromium.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
boris.ostrovsky@oracle.com, jgross@suse.com,
sstabellini@kernel.org, x86@kernel.org,
jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com,
rodrigo.vivi@intel.com, chris@chris-wilson.co.uk,
intel-gfx@lists.freedesktop.org, linux-mm@kvack.org, hch@lst.de
Subject: Re: [PATCH 4/7] mm: Introduce verify_page_range()
Date: Mon, 19 Apr 2021 16:36:12 -0700 [thread overview]
Message-ID: <202104191630.F00A6AAF@keescook> (raw)
In-Reply-To: <YHVADhpkETMQGD5X@hirez.programming.kicks-ass.net>
On Tue, Apr 13, 2021 at 08:54:06AM +0200, Peter Zijlstra wrote:
> On Mon, Apr 12, 2021 at 01:05:09PM -0700, Kees Cook wrote:
> > On Mon, Apr 12, 2021 at 10:00:16AM +0200, Peter Zijlstra wrote:
> > > +struct vpr_data {
> > > + int (*fn)(pte_t pte, unsigned long addr, void *data);
> > > + void *data;
> > > +};
> >
> > Eeerg. This is likely to become an attack target itself. Stored function
> > pointer with stored (3rd) argument.
>
> You got some further reading on that? How exactly are those exploited?
Sure, see "Executing code" in
https://googleprojectzero.blogspot.com/2017/05/exploiting-linux-kernel-via-packet.html
I killed the entire primitive (for timer_list)
https://outflux.net/blog/archives/2018/02/05/security-things-in-linux-v4-15/#v4.15-timer_list
but that was a lot of work, so I'm trying to avoid seeing more things
like it appear. :) (And I'm trying to get rid of similar APIs, like
tasklet.)
This new code is unlikely to ever be used as widely as timer_list,
but I just cringe when I see the code pattern. I'll understand if there
isn't a solution that doesn't require major refactoring, but I can
dream. :)
--
Kees Cook
WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook@chromium.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: jgross@suse.com, sstabellini@kernel.org,
intel-gfx@lists.freedesktop.org, x86@kernel.org,
linux-kernel@vger.kernel.org, chris@chris-wilson.co.uk,
linux-mm@kvack.org, boris.ostrovsky@oracle.com, hch@lst.de,
akpm@linux-foundation.org
Subject: Re: [Intel-gfx] [PATCH 4/7] mm: Introduce verify_page_range()
Date: Mon, 19 Apr 2021 16:36:12 -0700 [thread overview]
Message-ID: <202104191630.F00A6AAF@keescook> (raw)
In-Reply-To: <YHVADhpkETMQGD5X@hirez.programming.kicks-ass.net>
On Tue, Apr 13, 2021 at 08:54:06AM +0200, Peter Zijlstra wrote:
> On Mon, Apr 12, 2021 at 01:05:09PM -0700, Kees Cook wrote:
> > On Mon, Apr 12, 2021 at 10:00:16AM +0200, Peter Zijlstra wrote:
> > > +struct vpr_data {
> > > + int (*fn)(pte_t pte, unsigned long addr, void *data);
> > > + void *data;
> > > +};
> >
> > Eeerg. This is likely to become an attack target itself. Stored function
> > pointer with stored (3rd) argument.
>
> You got some further reading on that? How exactly are those exploited?
Sure, see "Executing code" in
https://googleprojectzero.blogspot.com/2017/05/exploiting-linux-kernel-via-packet.html
I killed the entire primitive (for timer_list)
https://outflux.net/blog/archives/2018/02/05/security-things-in-linux-v4-15/#v4.15-timer_list
but that was a lot of work, so I'm trying to avoid seeing more things
like it appear. :) (And I'm trying to get rid of similar APIs, like
tasklet.)
This new code is unlikely to ever be used as widely as timer_list,
but I just cringe when I see the code pattern. I'll understand if there
isn't a solution that doesn't require major refactoring, but I can
dream. :)
--
Kees Cook
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
next prev parent reply other threads:[~2021-04-19 23:36 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-12 8:00 [PATCH 0/7] mm: Unexport apply_to_page_range() Peter Zijlstra
2021-04-12 8:00 ` [Intel-gfx] " Peter Zijlstra
2021-04-12 8:00 ` [PATCH 1/7] mm: Unexport apply_to_existing_page_range() Peter Zijlstra
2021-04-12 8:00 ` [Intel-gfx] " Peter Zijlstra
2021-04-12 8:13 ` Christoph Hellwig
2021-04-12 8:13 ` [Intel-gfx] " Christoph Hellwig
2021-04-12 8:00 ` [PATCH 2/7] xen/gntdev,x86: Remove apply_to_page_range() use from module Peter Zijlstra
2021-04-12 8:00 ` [Intel-gfx] [PATCH 2/7] xen/gntdev, x86: " Peter Zijlstra
2021-04-12 8:26 ` [PATCH 2/7] xen/gntdev,x86: " Christoph Hellwig
2021-04-12 8:26 ` [Intel-gfx] [PATCH 2/7] xen/gntdev, x86: " Christoph Hellwig
2021-04-12 9:20 ` [PATCH 2/7] xen/gntdev,x86: " Peter Zijlstra
2021-04-12 9:20 ` [Intel-gfx] [PATCH 2/7] xen/gntdev, x86: " Peter Zijlstra
2021-04-12 9:26 ` [PATCH 2/7] xen/gntdev,x86: " Juergen Gross
2021-04-12 9:26 ` [Intel-gfx] [PATCH 2/7] xen/gntdev, x86: " Juergen Gross
2021-04-12 8:00 ` [PATCH 3/7] xen/gntdev: " Peter Zijlstra
2021-04-12 8:00 ` [Intel-gfx] " Peter Zijlstra
2021-04-12 8:27 ` Christoph Hellwig
2021-04-12 8:27 ` [Intel-gfx] " Christoph Hellwig
2021-04-12 9:02 ` Peter Zijlstra
2021-04-12 9:02 ` [Intel-gfx] " Peter Zijlstra
2021-04-12 8:00 ` [PATCH 4/7] mm: Introduce verify_page_range() Peter Zijlstra
2021-04-12 8:00 ` [Intel-gfx] " Peter Zijlstra
2021-04-12 8:28 ` Christoph Hellwig
2021-04-12 8:28 ` [Intel-gfx] " Christoph Hellwig
2021-04-12 9:17 ` Peter Zijlstra
2021-04-12 9:17 ` [Intel-gfx] " Peter Zijlstra
2021-04-12 20:05 ` Kees Cook
2021-04-12 20:05 ` [Intel-gfx] " Kees Cook
2021-04-13 6:54 ` Peter Zijlstra
2021-04-13 6:54 ` [Intel-gfx] " Peter Zijlstra
2021-04-19 23:36 ` Kees Cook [this message]
2021-04-19 23:36 ` Kees Cook
2021-04-13 7:36 ` Peter Zijlstra
2021-04-13 7:36 ` [Intel-gfx] " Peter Zijlstra
2021-04-14 3:01 ` Kees Cook
2021-04-14 3:01 ` [Intel-gfx] " Kees Cook
2021-04-14 7:00 ` Peter Zijlstra
2021-04-14 7:00 ` [Intel-gfx] " Peter Zijlstra
2021-04-12 8:00 ` [PATCH 5/7] xen/privcmd: Use verify_page_range() Peter Zijlstra
2021-04-12 8:00 ` [Intel-gfx] " Peter Zijlstra
2021-04-12 8:28 ` Christoph Hellwig
2021-04-12 8:28 ` [Intel-gfx] " Christoph Hellwig
2021-04-12 8:00 ` [PATCH 6/7] i915: Convert to verify_page_range() Peter Zijlstra
2021-04-12 8:00 ` [Intel-gfx] " Peter Zijlstra
2021-04-12 8:28 ` Christoph Hellwig
2021-04-12 8:28 ` [Intel-gfx] " Christoph Hellwig
2021-04-12 20:08 ` Kees Cook
2021-04-12 20:08 ` [Intel-gfx] " Kees Cook
2021-04-13 6:54 ` Peter Zijlstra
2021-04-13 6:54 ` [Intel-gfx] " Peter Zijlstra
2021-04-14 3:04 ` Kees Cook
2021-04-14 3:04 ` [Intel-gfx] " Kees Cook
2021-04-12 8:00 ` [PATCH 7/7] mm: Unexport apply_to_page_range() Peter Zijlstra
2021-04-12 8:00 ` [Intel-gfx] " Peter Zijlstra
2021-04-12 8:28 ` Christoph Hellwig
2021-04-12 8:28 ` [Intel-gfx] " Christoph Hellwig
2021-04-12 9:00 ` [Intel-gfx] ✗ Fi.CI.BUILD: failure for " Patchwork
2021-04-12 9:23 ` Peter Zijlstra
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