From: Bhavna Sarathy <bnagendr@redhat.com>
Date: Mon, 8 Jun 2009 15:37:33 -0400
Subject: [x86_64] iommu: protect against broken IVRS ACPI table
Message-id: 20090608193837.7837.6766.sendpatchset@localhost.localdomain
O-Subject: [RHEL5.4 PATCH 4/5] [KVM] Protect against broken IVRS ACPI table
Bugzilla: 501571
RH-Acked-by: Don Dutile <ddutile@redhat.com>
RH-Acked-by: Rik van Riel <riel@redhat.com>
RH-Acked-by: Juan Quintela <quintela@redhat.com>

Resolves BZ 501571

The bug never triggered. But it should be fixed to protect against
broken ACPI tables in the future.

diff --git a/arch/x86_64/kernel/amd_iommu_init.c b/arch/x86_64/kernel/amd_iommu_init.c
index aa21b95..e74dfb5 100644
--- a/arch/x86_64/kernel/amd_iommu_init.c
+++ b/arch/x86_64/kernel/amd_iommu_init.c
@@ -858,6 +858,8 @@ static int __init init_unity_map_range(struct ivmd_header *m)
 
 	switch (m->type) {
 	default:
+		kfree(e);
+		return(0);
 	case ACPI_IVMD_TYPE:
 		e->devid_start = e->devid_end = m->devid;
 		break;