From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>, Keir Fraser <keir@xen.org>
Subject: Re: [PATCH 2/4] x86: add address validity check to guest_map_l1e()
Date: Thu, 10 Oct 2013 14:57:51 +0100 [thread overview]
Message-ID: <5256B25F.2070507@citrix.com> (raw)
In-Reply-To: <5256CDA402000078000FA3E6@nat28.tlf.novell.com>
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On 10/10/13 14:54, Jan Beulich wrote:
> Just like for guest_get_eff_l1e() this prevents accessing as page
> tables (and with the wrong memory attribute) internal data inside Xen
> happening to be mapped with 1Gb pages.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper@citrix.com>
>
> --- a/xen/include/asm-x86/paging.h
> +++ b/xen/include/asm-x86/paging.h
> @@ -360,7 +360,8 @@ guest_map_l1e(struct vcpu *v, unsigned l
> return paging_get_hostmode(v)->guest_map_l1e(v, addr, gl1mfn);
>
> /* Find this l1e and its enclosing l1mfn in the linear map */
> - if ( __copy_from_user(&l2e,
> + if ( !__addr_ok(addr) ||
> + __copy_from_user(&l2e,
> &__linear_l2_table[l2_linear_offset(addr)],
> sizeof(l2_pgentry_t)) != 0 )
> return NULL;
>
>
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
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next prev parent reply other threads:[~2013-10-10 13:57 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-10 13:49 [PATCH 0/4] x86: XSA-67 follow-up Jan Beulich
2013-10-10 13:53 ` [PATCH 1/4] x86: correct LDT checks Jan Beulich
2013-10-10 13:54 ` [PATCH 2/4] x86: add address validity check to guest_map_l1e() Jan Beulich
2013-10-10 13:57 ` Andrew Cooper [this message]
2013-10-10 13:54 ` [PATCH 3/4] x86: use {rd, wr}{fs, gs}base when available Jan Beulich
2013-10-10 14:15 ` Andrew Cooper
2013-10-10 13:55 ` [PATCH 4/4] x86: check for canonical address before doing page walks Jan Beulich
2013-10-10 14:01 ` Andrew Cooper
2013-10-10 14:10 ` Jan Beulich
2013-10-10 14:17 ` Andrew Cooper
2013-10-10 15:13 ` [PATCH 0/4] x86: XSA-67 follow-up Keir Fraser
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