isdn: mISDNinfineon: fix potential NULL pointer dereference

In case ioremap fails, the fix returns -ENOMEM to avoid NULL
pointer dereference.

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

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/isdn/hardware/mISDN/mISDNinfineon.c b/drivers/isdn/hardware/mISDN/mISDNinfineon.c
index 3e01012be4ab..0fe6ddcb3fdc 100644
--- a/drivers/isdn/hardware/mISDN/mISDNinfineon.c
+++ b/drivers/isdn/hardware/mISDN/mISDNinfineon.c
@@ -712,8 +712,11 @@ setup_io(struct inf_hw *hw)
                                 (ulong)hw->addr.start, (ulong)hw->addr.size);
                         return err;
                 }
-                if (hw->ci->addr_mode == AM_MEMIO)
+                if (hw->ci->addr_mode == AM_MEMIO) {
                         hw->addr.p = ioremap(hw->addr.start, hw->addr.size);
+                        if (unlikely(!hw->addr.p))
+                                return -ENOMEM;
+                }
                 hw->addr.mode = hw->ci->addr_mode;
                 if (debug & DEBUG_HW)
                         pr_notice("%s: IO addr %lx (%lu bytes) mode%d\n",