netfilter: ipset: Fix an error code in ip_set_sockfn_get()

BugLink: https://bugs.launchpad.net/bugs/1852338
commit 30b7244d79651460ff114ba8f7987ed94c86b99a upstream.

The copy_to_user() function returns the number of bytes remaining to be
copied.  In this code, that positive return is checked at the end of the
function and we return zero/success.  What we should do instead is
return -EFAULT.

Fixes: a7b4f989a629 ("netfilter: ipset: IP set core support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index e64d5f9a89dd331e48ddf38af1c9978d2507a958..e7288eab7512609dbf851626c60be2829c17b4d0 100644 (file)
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -2069,8 +2069,9 @@ ip_set_sockfn_get(struct sock *sk, int optval, void __user *user, int *len)
                }
 
                req_version->version = IPSET_PROTOCOL;
-               ret = copy_to_user(user, req_version,
-                                  sizeof(struct ip_set_req_version));
+               if (copy_to_user(user, req_version,
+                                sizeof(struct ip_set_req_version)))
+                       ret = -EFAULT;
                goto done;
        }
        case IP_SET_OP_GET_BYNAME: {
@@ -2129,7 +2130,8 @@ ip_set_sockfn_get(struct sock *sk, int optval, void __user *user, int *len)
        }       /* end of switch(op) */
 
 copy:
-       ret = copy_to_user(user, data, copylen);
+       if (copy_to_user(user, data, copylen))
+               ret = -EFAULT;
 
 done:
        vfree(data);