xen/pciback: Check if the device is found instead of blindly assuming so.

Just in case it is not found, don't try to dereference it.

[v1: Added WARN_ON, suggested by Jan Beulich <JBeulich@suse.com>]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 3cc3fbe5bf8d..8f06e1ed028c 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -220,6 +220,8 @@ void pcistub_put_pci_dev(struct pci_dev *dev)
         }
 
         spin_unlock_irqrestore(&pcistub_devices_lock, flags);
+        if (WARN_ON(!found_psdev))
+                return;
 
         /*hold this lock for avoiding breaking link between
         * pcistub and xen_pcibk when AER is in processing