Commit b51fb771 authored Mar 28, 2020 by Michal Kubecek Committed by David S. Miller Mar 29, 2020

ethtool: fix reference leak in ethnl_set_privflags()



Andrew noticed that some handlers for *_SET commands leak a netdev
reference if required ethtool_ops callbacks do not exist. One of them is
ethnl_set_privflags(), a simple reproducer would be e.g.

  ip link add veth1 type veth peer name veth2
  ethtool --set-priv-flags veth1 foo on
  ip link del veth1

Make sure dev_put() is called when ethtool_ops check fails.

Fixes: f265d799 ("ethtool: set device private flags with PRIVFLAGS_SET request")
Reported-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 96376cad

net/ethtool/privflags.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -175,9 +175,10 @@ int ethnl_set_privflags(struct sk_buff skb, struct genl_info info)
		return ret;
		dev = req_info.dev;
		ops = dev->ethtool_ops;
		ret = -EOPNOTSUPP;
		if (!ops->get_priv_flags \|\| !ops->set_priv_flags \|\|
		!ops->get_sset_count \|\| !ops->get_strings)
		return -EOPNOTSUPP;
		goto out_dev;

		rtnl_lock();
		ret = ethnl_ops_begin(dev);
		@@ -204,6 +205,7 @@ out_ops:
		ethnl_ops_complete(dev);
		out_rtnl:
		rtnl_unlock();
		out_dev:
		dev_put(dev);
		return ret;
		}

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