File 59df6182-x86-dont-allow-MSI-pIRQ-mapping-on-unowned-device.patch of Package xen.10697

# Commit 3308374b1be7d43e23bd2e9eaf23ec06d7959882
# Date 2017-10-12 14:35:14 +0200
# Author Jan Beulich <jbeulich@suse.com>
# Committer Jan Beulich <jbeulich@suse.com>
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>

--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -1958,7 +1958,10 @@ 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 )
         {