firewire: nosy: do not ignore errors in ioremap_nocache()

There is no check if ioremap_nocache() returns a valid pointer.
Potentially it can lead to null pointer dereference.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (renamed goto labels)

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/firewire/nosy.c b/drivers/firewire/nosy.c
index 631c977b0da5..180f0a96528c 100644
--- a/drivers/firewire/nosy.c
+++ b/drivers/firewire/nosy.c
@@ -566,6 +566,11 @@ add_card(struct pci_dev *dev, const struct pci_device_id *unused)
 
         lynx->registers = ioremap_nocache(pci_resource_start(dev, 0),
                                           PCILYNX_MAX_REGISTER);
+        if (lynx->registers == NULL) {
+                dev_err(&dev->dev, "Failed to map registers\n");
+                ret = -ENOMEM;
+                goto fail_deallocate_lynx;
+        }
 
         lynx->rcv_start_pcl = pci_alloc_consistent(lynx->pci_device,
                                 sizeof(struct pcl), &lynx->rcv_start_pcl_bus);
@@ -578,7 +583,7 @@ add_card(struct pci_dev *dev, const struct pci_device_id *unused)
             lynx->rcv_buffer == NULL) {
                 dev_err(&dev->dev, "Failed to allocate receive buffer\n");
                 ret = -ENOMEM;
-                goto fail_deallocate;
+                goto fail_deallocate_buffers;
         }
         lynx->rcv_start_pcl->next       = cpu_to_le32(lynx->rcv_pcl_bus);
         lynx->rcv_pcl->next             = cpu_to_le32(PCL_NEXT_INVALID);
@@ -641,7 +646,7 @@ add_card(struct pci_dev *dev, const struct pci_device_id *unused)
                 dev_err(&dev->dev,
                         "Failed to allocate shared interrupt %d\n", dev->irq);
                 ret = -EIO;
-                goto fail_deallocate;
+                goto fail_deallocate_buffers;
         }
 
         lynx->misc.parent = &dev->dev;
@@ -668,7 +673,7 @@ fail_free_irq:
         reg_write(lynx, PCI_INT_ENABLE, 0);
         free_irq(lynx->pci_device->irq, lynx);
 
-fail_deallocate:
+fail_deallocate_buffers:
         if (lynx->rcv_start_pcl)
                 pci_free_consistent(lynx->pci_device, sizeof(struct pcl),
                                 lynx->rcv_start_pcl, lynx->rcv_start_pcl_bus);
@@ -679,6 +684,8 @@ fail_deallocate:
                 pci_free_consistent(lynx->pci_device, PAGE_SIZE,
                                 lynx->rcv_buffer, lynx->rcv_buffer_bus);
         iounmap(lynx->registers);
+
+fail_deallocate_lynx:
         kfree(lynx);
 
 fail_disable: