tipc: fix message importance range check

[ Upstream commit ac32c7f705692b92fe12dcbe88fe87136fdfff6f ]

Commit 3b4f302d8578 ("tipc: eliminate
redundant locking") introduced a bug by removing the sanity check
for message importance, allowing programs to assign any value to
the msg_user field. This will mess up the packet reception logic
and may cause random link resets.

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/tipc/port.h b/net/tipc/port.h
index cf4ca5b1d9a48ae7752f9f476cad079e3f115da8..3f34cac07a2ce4a98917b32c796ca2aa6c6c1c65 100644 (file)
--- a/net/tipc/port.h
+++ b/net/tipc/port.h
@@ -229,9 +229,12 @@ static inline int tipc_port_importance(struct tipc_port *port)
        return msg_importance(&port->phdr);
 }
 
-static inline void tipc_port_set_importance(struct tipc_port *port, int imp)
+static inline int tipc_port_set_importance(struct tipc_port *port, int imp)
 {
+       if (imp > TIPC_CRITICAL_IMPORTANCE)
+               return -EINVAL;
        msg_set_importance(&port->phdr, (u32)imp);
+       return 0;
 }
 
 #endif

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index ef0475568f9e39cfa3aa24d1d4d7a7132ea059a4..4093fd81edd5a2b50e66c3ed61821acea97a9d6d 100644 (file)
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -1841,7 +1841,7 @@ static int tipc_setsockopt(struct socket *sock, int lvl, int opt,
 
        switch (opt) {
        case TIPC_IMPORTANCE:
-               tipc_port_set_importance(port, value);
+               res = tipc_port_set_importance(port, value);
                break;
        case TIPC_SRC_DROPPABLE:
                if (sock->type != SOCK_STREAM)