2 files changed, 9 insertions, 0 deletions

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index c489ef2c1a39..34fc4189ebf0 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -298,12 +298,16 @@ static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
                         map_irq.entry_nr = nvec;
                 } else if (type == PCI_CAP_ID_MSIX) {
                         int pos;
+                        unsigned long flags;
                         u32 table_offset, bir;
 
                         pos = dev->msix_cap;
                         pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
                                               &table_offset);
                         bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
+                        flags = pci_resource_flags(dev, bir);
+                        if (!flags || (flags & IORESOURCE_UNSET))
+                                return -EINVAL;
 
                         map_irq.table_base = pci_resource_start(dev, bir);
                         map_irq.entry_nr = msidesc->msi_attrib.entry_nr;
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index fd60806d3fd0..c3e7dfcf9ff5 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -694,11 +694,16 @@ static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
 {
         resource_size_t phys_addr;
         u32 table_offset;
+        unsigned long flags;
         u8 bir;
 
         pci_read_config_dword(dev, dev->msix_cap + PCI_MSIX_TABLE,
                               &table_offset);
         bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
+        flags = pci_resource_flags(dev, bir);
+        if (!flags || (flags & IORESOURCE_UNSET))
+                return NULL;
+
         table_offset &= PCI_MSIX_TABLE_OFFSET;
         phys_addr = pci_resource_start(dev, bir) + table_offset;