nl80211: Check that function pointer != NULL before using it (f3f92586) · Commits · 戴 / test

NL80211_CMD_GET_MESH_PARAMS and NL80211_CMD_SET_MESH_PARAMS handlers did not verify whether a function pointer is NULL (not supported by the driver) before trying to call the function. The former nl80211 command is available for unprivileged users, too, so this can potentially allow normal users to kill networking (or worse..) if mac80211 is built without CONFIG_MAC80211_MESH=y. Signed-off-by:

Jouni Malinen <jouni.malinen@atheros.com> Signed-off-by:

John W. Linville <linville@tuxdriver.com>

net/wireless/nl80211.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -1908,6 +1908,11 @@ static int nl80211_get_mesh_params(struct sk_buff *skb,
		if (err)
		return err;

		if (!drv->ops->get_mesh_params) {
		err = -EOPNOTSUPP;
		goto out;
		}

		/* Get the mesh params */
		rtnl_lock();
		err = drv->ops->get_mesh_params(&drv->wiphy, dev, &cur_params);
		@@ -2017,6 +2022,11 @@ static int nl80211_set_mesh_params(struct sk_buff skb, struct genl_info info)
		if (err)
		return err;

		if (!drv->ops->set_mesh_params) {
		err = -EOPNOTSUPP;
		goto out;
		}

		/* This makes sure that there aren't more than 32 mesh config
		* parameters (otherwise our bitfield scheme would not work.) */
		BUILD_BUG_ON(NL80211_MESHCONF_ATTR_MAX > 32);
		@@ -2061,6 +2071,7 @@ static int nl80211_set_mesh_params(struct sk_buff skb, struct genl_info info)
		err = drv->ops->set_mesh_params(&drv->wiphy, dev, &cfg, mask);
		rtnl_unlock();

		out:
		/* cleanup */
		cfg80211_put_dev(drv);
		dev_put(dev);

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