From 4b0303c2ae47decae500898d99ce78b8f9a3155b Mon Sep 17 00:00:00 2001
From: Taehee Yoo <ap420073@gmail.com>
Date: Thu, 27 Feb 2020 12:25:19 +0000
Subject: [PATCH 05/12] net: rmnet: do not allow to change mux id if mux id is
duplicated
Git-commit: 1dc49e9d164cd7e11c81279c83db84a147e14740
Patch-mainline: v5.6-rc4
References: git-fixes
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 <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c | 4 ++++
1 file changed, 4 insertions(+)
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;
--
2.16.4