staging: kpc2000: prevent underflow in cpld_reconfigure()

commit 72db61d7d17a475d3cc9de1a7c871d518fcd82f0 upstream.

This function should not allow negative values of "wr_val".  If
negatives are allowed then capping the upper bound at 7 is
meaningless.  Let's make it unsigned.

Fixes: 7dc7967fc39a ("staging: kpc2000: add initial set of Daktronics drivers")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200224103325.hrxdnaeqsthplu42@kili.mountain
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dan Carpenter
2020-02-24 13:33:25 +03:00
committed by Greg Kroah-Hartman
parent b958dea86c
commit fea3939c6c

View File

@ -110,10 +110,10 @@ static ssize_t cpld_reconfigure(struct device *dev,
const char *buf, size_t count)
{
struct kp2000_device *pcard = dev_get_drvdata(dev);
long wr_val;
unsigned long wr_val;
int rv;
rv = kstrtol(buf, 0, &wr_val);
rv = kstrtoul(buf, 0, &wr_val);
if (rv < 0)
return rv;
if (wr_val > 7)