From: Jan Beulich <jbeulich@suse.com>
Date: Thu, 12 Oct 2017 12:35:14 +0000 (+0200)
Subject: x86: don't allow MSI pIRQ mapping on unowned device
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=3308374b1be7d43e23bd2e9eaf23ec06d7959882;p=people%2Fiwj%2Fxen.git

x86: don't allow MSI pIRQ mapping on unowned device

MSI setup should be permitted only for existing devices owned by the
respective guest (the operation may still be carried out by the domain
controlling that guest).

This is part of XSA-237.

Reported-by: HW42 <hw42@ipsumj.de>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index 77ca181985..382b1f3ed2 100644
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -1972,7 +1972,10 @@ int map_domain_pirq(
         if ( !cpu_has_apic )
             goto done;
 
-        pdev = pci_get_pdev(msi->seg, msi->bus, msi->devfn);
+        pdev = pci_get_pdev_by_domain(d, msi->seg, msi->bus, msi->devfn);
+        if ( !pdev )
+            goto done;
+
         ret = pci_enable_msi(msi, &msi_desc);
         if ( ret )
         {