[PATCH v5 1/9] hvm_set_ioreq_page() releases wrong page in error path

[Paul Durrant <paul.durrant@citrix.com>]

The function calls prepare_ring_for_helper() to acquire a mapping for the
given gmfn, then checks (under lock) to see if the ioreq page is already
set up but, if it is, the function then releases the in-use ioreq page
mapping on the error path rather than the one it just acquired. This patch
fixes this bug.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Keir Fraser <keir@xen.org>
Cc: Jan Beulich <jbeulich@suse.com>
---
 xen/arch/x86/hvm/hvm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index ac05160..3dec1eb 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -496,7 +496,7 @@ static int hvm_set_ioreq_page(
 
     if ( (iorp->va != NULL) || d->is_dying )
     {
-        destroy_ring_for_helper(&iorp->va, iorp->page);
+        destroy_ring_for_helper(&va, page);
         spin_unlock(&iorp->lock);
         return -EINVAL;
     }
-- 
1.7.10.4