From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> 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@xxxxxxxxxx> Signed-off-by: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/netfilter/ipset/ip_set_core.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -1942,8 +1942,9 @@ ip_set_sockfn_get(struct sock *sk, int o } 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: { @@ -2000,7 +2001,8 @@ ip_set_sockfn_get(struct sock *sk, int o } /* end of switch(op) */ copy: - ret = copy_to_user(user, data, copylen); + if (copy_to_user(user, data, copylen)) + ret = -EFAULT; done: vfree(data);