net/netrom: Fix socket locking

upstream commit: cc29c70dd581f85ee7a3e7980fb031f90b90a2ab

Patch "af_rose/x25: Sanity check the maximum user frame size"
(commit 83e0bbcbe2145f160fbaa109b0439dae7f4a38a9) from Alan Cox got
locking wrong. If we bail out due to user frame size being too large,
we must unlock the socket beforehand.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
index 2d7fbe7e12db95e8265b485871261ea2ca0ea189..dcce77871da32a72de7068dfbb7c41db67fc8e0f 100644 (file)
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -1084,8 +1084,10 @@ static int nr_sendmsg(struct kiocb *iocb, struct socket *sock,
 
        /* Build a packet - the conventional user limit is 236 bytes. We can
           do ludicrously large NetROM frames but must not overflow */
-       if (len > 65536)
-               return -EMSGSIZE;
+       if (len > 65536) {
+               err = -EMSGSIZE;
+               goto out;
+       }
 
        SOCK_DEBUG(sk, "NET/ROM: sendto: building packet.\n");
        size = len + NR_NETWORK_LEN + NR_TRANSPORT_LEN;