blob: a5e9f5171115f6dbbcb11b070ff1fc8a693dee77 [file] [log] [blame]
From 36ffa419f9e83f906b07456dfeedfb0e798b5bdc Mon Sep 17 00:00:00 2001
From: Taehee Yoo <>
Date: Thu, 27 Feb 2020 12:25:19 +0000
Subject: [PATCH] net: rmnet: do not allow to change mux id if mux id is
commit 1dc49e9d164cd7e11c81279c83db84a147e14740 upstream.
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: 23790ef12082 ("net: qualcomm: rmnet: Allow to configure flags for existing devices")
Signed-off-by: Taehee Yoo <>
Signed-off-by: David S. Miller <>
Signed-off-by: Paul Gortmaker <>
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
index 0ad64aa66592..3c0e6d24d083 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
@@ -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;