From: Jan Beulich <JBeulich@suse.com>
Date: Tue, 8 Nov 2016 07:43:54 +0000 (-0700)
Subject: PCI/MSI: Check for NULL affinity mask in pci_irq_get_affinity()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d1d111e073840b8dbc1ae90ba3fc274736451bdc;p=linux-beck.git

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

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>
---

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index bfdd0744b686..da4e3c1248db 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1292,7 +1292,8 @@ 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];