From: Mihai Donțu <mdontu@bitdefender.com>
Date: Tue, 6 Jan 2015 12:52:21 +0000 (+0000)
Subject: x86/HVM: prevent use-after-free when destroying a domain
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=95af3f09eeef089e0100a8518f7ca75206e33c7c;p=xen.git

x86/HVM: prevent use-after-free when destroying a domain

hvm_domain_relinquish_resources() can free certain domain resources
which can still be accessed, e.g. by HVMOP_set_param, while the domain
is being cleaned up.

Signed-off-by: Mihai Donțu <mdontu@bitdefender.com>
Tested-by: Răzvan Cojocaru <rcojocaru@bitdefender.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

This is CVE-2015-0361 / XSA-116.
(cherry picked from commit 5d4e3ff19c33770ce01bec949c50326b11088fef)
---

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 4be249e424..dcac4ad962 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -579,13 +579,13 @@ void hvm_domain_relinquish_resources(struct domain *d)
         hpet_deinit(d);
     }
 
-    xfree(d->arch.hvm_domain.io_handler);
-    xfree(d->arch.hvm_domain.params);
     xfree(d->arch.hvm_domain.pbuf);
 }
 
 void hvm_domain_destroy(struct domain *d)
 {
+    xfree(d->arch.hvm_domain.io_handler);
+    xfree(d->arch.hvm_domain.params);
     hvm_funcs.domain_destroy(d);
     rtc_deinit(d);
     stdvga_deinit(d);