isdn: hfcpci: fix potential NULL pointer dereference

In case ioremap fails, the fix releases resources and returns.
The following printk is for logging purpose and thus is
preserved.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/isdn/hardware/mISDN/hfcpci.c b/drivers/isdn/hardware/mISDN/hfcpci.c
index ebb3fa2e1d00..362aa5450a5e 100644
--- a/drivers/isdn/hardware/mISDN/hfcpci.c
+++ b/drivers/isdn/hardware/mISDN/hfcpci.c
@@ -2032,10 +2032,19 @@ setup_hw(struct hfc_pci *hc)
         hc->hw.fifos = buffer;
         pci_write_config_dword(hc->pdev, 0x80, hc->hw.dmahandle);
         hc->hw.pci_io = ioremap((ulong) hc->hw.pci_io, 256);
+        if (unlikely(!hc->hw.pci_io)) {
+                printk(KERN_WARNING
+                       "HFC-PCI: Error in ioremap for PCI!\n");
+                pci_free_consistent(hc->pdev, 0x8000, hc->hw.fifos,
+                                    hc->hw.dmahandle);
+                return 1;
+        }
+
         printk(KERN_INFO
                "HFC-PCI: defined at mem %#lx fifo %#lx(%#lx) IRQ %d HZ %d\n",
                (u_long) hc->hw.pci_io, (u_long) hc->hw.fifos,
                (u_long) hc->hw.dmahandle, hc->irq, HZ);
+
         /* enable memory mapped ports, disable busmaster */
         pci_write_config_word(hc->pdev, PCI_COMMAND, PCI_ENA_MEMIO);
         hc->hw.int_m2 = 0;