If "newmtu * 2 + 4" is too large then it can cause an integer overflow
leading to memory corruption. Btw, "newmtu" is not allowed to be a
negative number because of the check in dev_set_mtu(), so that's ok.
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
diff --git a/drivers/net/wan/x25_asy.c b/drivers/net/wan/x25_asy.c
index 5895f19..f04c8c1 100644
--- a/drivers/net/wan/x25_asy.c
+++ b/drivers/net/wan/x25_asy.c
@@ -122,8 +122,11 @@ static int x25_asy_change_mtu(struct net_device *dev, int newmtu)
{
struct x25_asy *sl = netdev_priv(dev);
unsigned char *xbuff, *rbuff;
- int len = 2 * newmtu;
+ int len;
+ if (newmtu > INT_MAX / 2 - 4)
+ return -EINVAL;
+ len = 2 * newmtu;
xbuff = kmalloc(len + 4, GFP_ATOMIC);
rbuff = kmalloc(len + 4, GFP_ATOMIC);
--
To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
