net: rmnet: do not allow to change mux id if mux id is duplicated

Basically, duplicate mux id isn't be allowed.
So, the creation of rmnet will be failed if there is duplicate mux id
is existing.
But, changelink routine doesn't check duplicate mux id.

Test commands:
    modprobe rmnet
    ip link add dummy0 type dummy
    ip link add rmnet0 link dummy0 type rmnet mux_id 1
    ip link add rmnet1 link dummy0 type rmnet mux_id 2
    ip link set rmnet1 type rmnet mux_id 1

Fixes: 23790ef120 ("net: qualcomm: rmnet: Allow to configure flags for existing devices")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Taehee Yoo 2020-02-27 12:25:19 +00:00 committed by David S. Miller
parent c026d97010
commit 1dc49e9d16

View File

@ -306,6 +306,10 @@ static int rmnet_changelink(struct net_device *dev, struct nlattr *tb[],
if (data[IFLA_RMNET_MUX_ID]) {
mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]);
if (rmnet_get_endpoint(port, mux_id)) {
NL_SET_ERR_MSG_MOD(extack, "MUX ID already exists");
return -EINVAL;
}
ep = rmnet_get_endpoint(port, priv->mux_id);
if (!ep)
return -ENODEV;