PCI/MSI: Check for NULL affinity mask in pci_irq_get_affinity()

commit d1d111e073840b8dbc1ae90ba3fc274736451bdc upstream.

If msi_setup_entry() fails to allocate an affinity mask, it logs a message
but continues on and allocates an MSI entry with entry->affinity == NULL.

Check for this case in pci_irq_get_affinity() so we don't try to
dereference a NULL pointer.

[bhelgaas: changelog]
Fixes: ee8d41e53efe "pci/msi: Retrieve affinity for a vector"
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index ad70507..3455f75 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1294,7 +1294,8 @@ const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
        } else if (dev->msi_enabled) {
                struct msi_desc *entry = first_pci_msi_entry(dev);
 
-               if (WARN_ON_ONCE(!entry || nr >= entry->nvec_used))
+               if (WARN_ON_ONCE(!entry || !entry->affinity ||
+                                nr >= entry->nvec_used))
                        return NULL;
 
                return &entry->affinity[nr];