ipx: call ipxitf_put() in ioctl error path

CVE-2017-7487

We should call ipxitf_put() if the copy_to_user() fails.

Reported-by: 李强 <liqiang6-s@360.cn>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit ee0d8d8482345ff97a75a7d747efc309f13b0d80)
Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/net/ipx/af_ipx.c b/net/ipx/af_ipx.c
index 8a9219ff2e77e0205de652974a44c5e4ba33b2c0..fa31ef29e3fa0bf3973e12e43c57b48eb7d1be45 100644 (file)
--- a/net/ipx/af_ipx.c
+++ b/net/ipx/af_ipx.c
@@ -1168,11 +1168,10 @@ static int ipxitf_ioctl(unsigned int cmd, void __user *arg)
                sipx->sipx_network      = ipxif->if_netnum;
                memcpy(sipx->sipx_node, ipxif->if_node,
                        sizeof(sipx->sipx_node));
-               rc = -EFAULT;
+               rc = 0;
                if (copy_to_user(arg, &ifr, sizeof(ifr)))
-                       break;
+                       rc = -EFAULT;
                ipxitf_put(ipxif);
-               rc = 0;
                break;
        }
        case SIOCAIPXITFCRT: