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

[ Upstream commit 1dc49e9d16 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Taehee Yoo
2020-02-27 12:25:19 +00:00
committed by Greg Kroah-Hartman
parent 7111ec0927
commit 48c5bfbbce

View File

@@ -315,6 +315,10 @@ 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;