[PATCH v2] isdn: hfcpci: fix potential NULL pointer dereference

From: Kangjie Lu
Date: Tue Mar 12 2019 - 01:55:42 EST


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@xxxxxxx>
---
drivers/isdn/hardware/mISDN/hfcpci.c | 9 +++++++++
1 file changed, 9 insertions(+)

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;
--
2.17.1