net/llc: make opt unsigned in llc_ui_setsockopt()

The members of struct llc_sock are unsigned so if we pass a negative
value for "opt" it can cause a sign bug.  Also it can cause an integer
overflow when we multiply "opt * HZ".

CC: stable@kernel.org
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 023ba820236f391a01595418873b7c5e0df3ece8..582612998211d24aa8d4aea919eed1ba1e994db3 100644 (file)
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -1024,7 +1024,8 @@ static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
 {
        struct sock *sk = sock->sk;
        struct llc_sock *llc = llc_sk(sk);
-       int rc = -EINVAL, opt;
+       unsigned int opt;
+       int rc = -EINVAL;
 
        lock_sock(sk);
        if (unlikely(level != SOL_LLC || optlen != sizeof(int)))