[libvirt] [PATCH 2/3] qemu: prevent invalid reads in qemuAssignDevicePCISlots

[Ján Tomko]

Don't reserve slot 2 for video if the machine has no PCI buses.
Error out when the user specifies a video device without
a PCI address when there are no PCI buses.

(This wouldn't work on a machine with no PCI bus anyway since
we do add PCI addresses for video devices to the command line)
---
 src/qemu/qemu_command.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 915a8dd..9737609 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -1827,6 +1827,9 @@ qemuAssignDevicePCISlots(virDomainDefPtr def,
             primaryVideo->info.addr.pci.function = 0;
             addrptr = &primaryVideo->info.addr.pci;
 
+            if (!qemuPCIAddressValidate(addrs, addrptr))
+                goto error;
+
             if (qemuDomainPCIAddressSlotInUse(addrs, addrptr)) {
                 if (qemuDeviceVideoUsable) {
                     virResetLastError();
@@ -1853,7 +1856,7 @@ qemuAssignDevicePCISlots(virDomainDefPtr def,
             /* If TYPE==PCI, then qemuCollectPCIAddress() function
              * has already reserved the address, so we must skip */
         }
-    } else if (!qemuDeviceVideoUsable) {
+    } else if (addrs->nbuses && !qemuDeviceVideoUsable) {
         memset(&tmp_addr, 0, sizeof(tmp_addr));
         tmp_addr.slot = 2;
 
-- 
1.8.1.5