[PATCH 4.4 168/241] tty: ipwireless: fix missing checks for ioremap

[Greg Kroah-Hartman]

[ Upstream commit 1bbb1c318cd8a3a39e8c3e2e83d5e90542d6c3e3 ]

ipw->attr_memory and ipw->common_memory are assigned with the
return value of ioremap. ioremap may fail, but no checks
are enforced. The fix inserts the checks to avoid potential
NULL pointer dereferences.

Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/tty/ipwireless/main.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/tty/ipwireless/main.c b/drivers/tty/ipwireless/main.c
index 655c7948261c7..2fa4f91234693 100644
--- a/drivers/tty/ipwireless/main.c
+++ b/drivers/tty/ipwireless/main.c
@@ -113,6 +113,10 @@ static int ipwireless_probe(struct pcmcia_device *p_dev, void *priv_data)
 
 	ipw->common_memory = ioremap(p_dev->resource[2]->start,
 				resource_size(p_dev->resource[2]));
+	if (!ipw->common_memory) {
+		ret = -ENOMEM;
+		goto exit1;
+	}
 	if (!request_mem_region(p_dev->resource[2]->start,
 				resource_size(p_dev->resource[2]),
 				IPWIRELESS_PCCARD_NAME)) {
@@ -133,6 +137,10 @@ static int ipwireless_probe(struct pcmcia_device *p_dev, void *priv_data)
 
 	ipw->attr_memory = ioremap(p_dev->resource[3]->start,
 				resource_size(p_dev->resource[3]));
+	if (!ipw->attr_memory) {
+		ret = -ENOMEM;
+		goto exit3;
+	}
 	if (!request_mem_region(p_dev->resource[3]->start,
 				resource_size(p_dev->resource[3]),
 				IPWIRELESS_PCCARD_NAME)) {
-- 
2.20.1