From: Kangjie Lu <kjlu@umn.edu>
Date: Tue, 12 Mar 2019 05:54:55 +0000 (-0500)
Subject: isdn: hfcpci: fix potential NULL pointer dereference
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=10010493c1261ca3d7444d372f281009890a5ff7;p=openwrt%2Fstaging%2Fblogic.git

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>
---

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;