From: Brenden Blanco <bblanco@plumgrid.com>
Date: Thu, 21 Jul 2016 00:22:34 +0000 (-0700)
Subject: rtnl: protect do_setlink from IFLA_XDP_ATTACHED
X-Git-Tag: v4.8-rc1~140^2~50^2~1
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=262d8625045e0c81b7859ecd192e9811710f19da;p=karo-tx-linux.git

rtnl: protect do_setlink from IFLA_XDP_ATTACHED

The IFLA_XDP_ATTACHED nested attribute is meant for read-only, and while
do_setlink properly ignores it, it should be more paranoid and reject
commands that try to set it.

Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index eba2b8260dbd..189cc78c77eb 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2109,6 +2109,10 @@ static int do_setlink(const struct sk_buff *skb,
 		if (err < 0)
 			goto errout;
 
+		if (xdp[IFLA_XDP_ATTACHED]) {
+			err = -EINVAL;
+			goto errout;
+		}
 		if (xdp[IFLA_XDP_FD]) {
 			err = dev_change_xdp_fd(dev,
 						nla_get_s32(xdp[IFLA_XDP_FD]));