From: Chris Wilson <chris@chris-wilson.co.uk>
To: Dan Carpenter <error27@gmail.com>
Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org
Subject: Re: bug report: potential integer overflow in validate_exec_list()
Date: Sun, 21 Nov 2010 09:23:46 +0000 [thread overview]
Message-ID: <849307$af353c@azsmga001.ch.intel.com> (raw)
In-Reply-To: <20101120183207.GC1522@bicker>
On Sat, 20 Nov 2010 21:32:07 +0300, Dan Carpenter <error27@gmail.com> wrote:
> Hello Chris,
>
> Is there an integer overflow in validate_exec_list()?
>
> drivers/gpu/drm/i915/i915_gem.c
> 3633 size_t length = exec[i].relocation_count * sizeof(struct drm_i915_gem_relocation_entry);
> 3634
> 3635 if (!access_ok(VERIFY_READ, ptr, length))
> 3636 return -EFAULT;
> 3637
>
> My concern is that if relocation_count is larger than 0x8000000 the
> multiplication can wrap.
Yes, it could. Not through normal use since relocation count can not be
more than buffer length, hence realistically capped at around 4k entries.
However...
Thanks,
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
next prev parent reply other threads:[~2010-11-21 9:23 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-20 18:32 bug report: potential integer overflow in validate_exec_list() Dan Carpenter
2010-11-21 9:23 ` Chris Wilson [this message]
2010-11-22 9:56 ` Dan Carpenter
2010-11-22 10:35 ` Chris Wilson
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