[PATCH 4.19 030/113] mISDN: Check address length before reading address family

[Greg Kroah-Hartman]

[ Upstream commit 238ffdc49ef98b15819cfd5e3fb23194e3ea3d39 ]

KMSAN will complain if valid address length passed to bind() is shorter
than sizeof("struct sockaddr_mISDN"->family) bytes.

Signed-off-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/isdn/mISDN/socket.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/isdn/mISDN/socket.c b/drivers/isdn/mISDN/socket.c
index 18c0a1281914f..b2abc44fa5cb8 100644
--- a/drivers/isdn/mISDN/socket.c
+++ b/drivers/isdn/mISDN/socket.c
@@ -711,10 +711,10 @@ base_sock_bind(struct socket *sock, struct sockaddr 
*addr, int addr_len)
        struct sock *sk = sock->sk;
        int err = 0;
 
-       if (!maddr || maddr->family != AF_ISDN)
+       if (addr_len < sizeof(struct sockaddr_mISDN))
                return -EINVAL;
 
-       if (addr_len < sizeof(struct sockaddr_mISDN))
+       if (!maddr || maddr->family != AF_ISDN)
                return -EINVAL;
 
        lock_sock(sk);
-- 
2.20.1