From: Roger Pau Monne <roger.pau@citrix.com>
Date: Mon, 27 Feb 2017 12:14:38 +0000 (+0000)
Subject: x86/PVHv2: fix dereference of native RSDP table mapping
X-Git-Tag: archive/raspbian/4.11.1-1+rpi1~1^2~66^2~2664
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=12f687bf28e23fa662bb518311c4ec71e5b39ab8;p=xen.git

x86/PVHv2: fix dereference of native RSDP table mapping

Check that the RSDP is mapped before trying to access it.

Spotted-by: Coverity
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/domain_build.c b/xen/arch/x86/domain_build.c
index d74296509a..78ae741bc5 100644
--- a/xen/arch/x86/domain_build.c
+++ b/xen/arch/x86/domain_build.c
@@ -2592,6 +2592,11 @@ static int __init pvh_setup_acpi(struct domain *d, paddr_t start_info)
 
     /* Craft a custom RSDP. */
     native_rsdp = acpi_os_map_memory(acpi_os_get_root_pointer(), sizeof(rsdp));
+    if ( !native_rsdp )
+    {
+        printk("Failed to map native RSDP\n");
+        return -ENOMEM;
+    }
     memcpy(rsdp.oem_id, native_rsdp->oem_id, sizeof(rsdp.oem_id));
     acpi_os_unmap_memory(native_rsdp, sizeof(rsdp));
     rsdp.xsdt_physical_address = xsdt_paddr;