Bluetooth: L2CAP: uninitialized variables in l2cap_sock_setsockopt()

[ Upstream commit 2b70d4f9b20635ac328836e50d183632e1930f94 ]

The "opt" variable is a u32, but on some paths only the top bytes
were initialized and the others contained random stack data.

Fixes: a7b75c5a8c41 ("net: pass a sockptr_t into ->setsockopt")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 251017c69ab7ffad7a8f120e5ff4c865203fde6f..d2c67852059921bfd188eee1a4a79736f9415323 100644 (file)
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -903,6 +903,8 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname,
        struct l2cap_conn *conn;
        int len, err = 0;
        u32 opt;
+       u16 mtu;
+       u8 mode;
 
        BT_DBG("sk %p", sk);
 
@@ -1085,16 +1087,16 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname,
                        break;
                }
 
-               if (copy_from_sockptr(&opt, optval, sizeof(u16))) {
+               if (copy_from_sockptr(&mtu, optval, sizeof(u16))) {
                        err = -EFAULT;
                        break;
                }
 
                if (chan->mode == L2CAP_MODE_EXT_FLOWCTL &&
                    sk->sk_state == BT_CONNECTED)
-                       err = l2cap_chan_reconfigure(chan, opt);
+                       err = l2cap_chan_reconfigure(chan, mtu);
                else
-                       chan->imtu = opt;
+                       chan->imtu = mtu;
 
                break;
 
@@ -1116,14 +1118,14 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname,
                        break;
                }
 
-               if (copy_from_sockptr(&opt, optval, sizeof(u8))) {
+               if (copy_from_sockptr(&mode, optval, sizeof(u8))) {
                        err = -EFAULT;
                        break;
                }
 
-               BT_DBG("opt %u", opt);
+               BT_DBG("mode %u", mode);
 
-               err = l2cap_set_mode(chan, opt);
+               err = l2cap_set_mode(chan, mode);
                if (err)
                        break;