tty: ipwireless: fix missing checks for ioremap

BugLink: https://bugs.launchpad.net/bugs/1837517
[ 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@umn.edu>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/tty/ipwireless/main.c b/drivers/tty/ipwireless/main.c
index 3475e841ef5c1f9c1902a2991ca9aa2da26d0729..4c18bbfe1a92ee9359f5c14d5e228c43fbd9fb34 100644 (file)
--- a/drivers/tty/ipwireless/main.c
+++ b/drivers/tty/ipwireless/main.c
@@ -114,6 +114,10 @@ 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)) {
@@ -134,6 +138,10 @@ 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)) {