Bluetooth: Fix potential NULL dereference in RFCOMM bind callback

addr can be NULL and it should not be dereferenced before NULL checking.

Signed-off-by: Jaganath Kanakkassery <jaganath.k@samsung.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 12 insertions, 8 deletions

diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index b2338e971b33..7511df72347f 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -334,16 +334,19 @@ static int rfcomm_sock_create(struct net *net, struct socket *sock,
 
 static int rfcomm_sock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 {
-        struct sockaddr_rc *sa = (struct sockaddr_rc *) addr;
+        struct sockaddr_rc sa;
         struct sock *sk = sock->sk;
-        int chan = sa->rc_channel;
-        int err = 0;
-
-        BT_DBG("sk %p %pMR", sk, &sa->rc_bdaddr);
+        int len, err = 0;
 
         if (!addr || addr->sa_family != AF_BLUETOOTH)
                 return -EINVAL;
 
+        memset(&sa, 0, sizeof(sa));
+        len = min_t(unsigned int, sizeof(sa), addr_len);
+        memcpy(&sa, addr, len);
+
+        BT_DBG("sk %p %pMR", sk, &sa.rc_bdaddr);
+
         lock_sock(sk);
 
         if (sk->sk_state != BT_OPEN) {
@@ -358,12 +361,13 @@ static int rfcomm_sock_bind(struct socket *sock, struct sockaddr *addr, int addr
 
         write_lock(&rfcomm_sk_list.lock);
 
-        if (chan && __rfcomm_get_listen_sock_by_addr(chan, &sa->rc_bdaddr)) {
+        if (sa.rc_channel &&
+            __rfcomm_get_listen_sock_by_addr(sa.rc_channel, &sa.rc_bdaddr)) {
                 err = -EADDRINUSE;
         } else {
                 /* Save source address */
-                bacpy(&rfcomm_pi(sk)->src, &sa->rc_bdaddr);
-                rfcomm_pi(sk)->channel = chan;
+                bacpy(&rfcomm_pi(sk)->src, &sa.rc_bdaddr);
+                rfcomm_pi(sk)->channel = sa.rc_channel;
                 sk->sk_state = BT_BOUND;
         }