linux-kernel - Re: [PATCH v2 1/2] kvm: unmap pages from the iommu when slots are removed

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20120412020357.GB3037@amt.cnet>
Date:	Wed, 11 Apr 2012 23:03:57 -0300
From:	Marcelo Tosatti <mtosatti@...hat.com>
To:	Alex Williamson <alex.williamson@...hat.com>
Cc:	kvm@...r.kernel.org, linux-kernel@...r.kernel.org, avi@...hat.com,
	jan.kiszka@...mens.com
Subject: Re: [PATCH v2 1/2] kvm: unmap pages from the iommu when slots are
 removed

On Wed, Apr 11, 2012 at 09:51:49AM -0600, Alex Williamson wrote:
> We've been adding new mappings, but not destroying old mappings.
> This can lead to a page leak as pages are pinned using
> get_user_pages, but only unpinned with put_page if they still
> exist in the memslots list on vm shutdown.  A memslot that is
> destroyed while an iommu domain is enabled for the guest will
> therefore result in an elevated page reference count that is
> never cleared.
> 
> Additionally, without this fix, the iommu is only programmed
> with the first translation for a gpa.  This can result in
> peer-to-peer errors if a mapping is destroyed and replaced by a
> new mapping at the same gpa as the iommu will still be pointing
> to the original, pinned memory address.
> 
> Signed-off-by: Alex Williamson <alex.williamson@...hat.com>

Applied, thanks.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/