llc: Check address length before reading address field

KMSAN will complain if valid address length passed to bind() is shorter
than sizeof(struct sockaddr_llc) bytes.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index b99e73a7e7e0f2b4959b279e3aecbadf29667d55..2017b7d780f5af73c1ac7461113842776d1b00fc 100644 (file)
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -320,14 +320,13 @@ static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
        struct llc_sap *sap;
        int rc = -EINVAL;
 
-       dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
-
        lock_sock(sk);
        if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
                goto out;
        rc = -EAFNOSUPPORT;
        if (unlikely(addr->sllc_family != AF_LLC))
                goto out;
+       dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
        rc = -ENODEV;
        rcu_read_lock();
        if (sk->sk_bound_dev_if) {