Commit f990874b authored by Dinghao Liu's avatar Dinghao Liu Committed by Stefan Schmidt
Browse files

ieee802154: ca8210: Fix a potential UAF in ca8210_probe 



If of_clk_add_provider() fails in ca8210_register_ext_clock(),
it calls clk_unregister() to release priv->clk and returns an
error. However, the caller ca8210_probe() then calls ca8210_remove(),
where priv->clk is freed again in ca8210_unregister_ext_clock(). In
this case, a use-after-free may happen in the second time we call
clk_unregister().

Fix this by removing the first clk_unregister(). Also, priv->clk could
be an error code on failure of clk_register_fixed_rate(). Use
IS_ERR_OR_NULL to catch this case in ca8210_unregister_ext_clock().

Fixes: ded845a7 ("ieee802154: Add CA8210 IEEE 802.15.4 device driver")
Signed-off-by: default avatarDinghao Liu <dinghao.liu@zju.edu.cn>
Message-ID: <20231007033049.22353-1-dinghao.liu@zju.edu.cn>
Signed-off-by: default avatarStefan Schmidt <stefan@datenfreihafen.org>
parent a2e52554

drivers/net/ieee802154/ca8210.c

+3 −14
Original line number Diff line number Diff line
@@ -2740,7 +2740,6 @@ static int ca8210_register_ext_clock(struct spi_device *spi) 
	struct device_node *np = spi->dev.of_node;

	struct ca8210_priv *priv = spi_get_drvdata(spi);

	struct ca8210_platform_data *pdata = spi->dev.platform_data;

	int ret = 0;



	if (!np)

		return -EFAULT;
@@ -2757,18 +2756,8 @@ static int ca8210_register_ext_clock(struct spi_device *spi) 
		dev_crit(&spi->dev, "Failed to register external clk\n");

		return PTR_ERR(priv->clk);

	}

	ret = of_clk_add_provider(np, of_clk_src_simple_get, priv->clk);

	if (ret) {

		clk_unregister(priv->clk);

		dev_crit(

			&spi->dev,

			"Failed to register external clock as clock provider\n"

		);

	} else {

		dev_info(&spi->dev, "External clock set as clock provider\n");

	}



	return ret;

	return of_clk_add_provider(np, of_clk_src_simple_get, priv->clk);

}



/**
@@ -2780,8 +2769,8 @@ static void ca8210_unregister_ext_clock(struct spi_device *spi) 
{

	struct ca8210_priv *priv = spi_get_drvdata(spi);



	if (!priv->clk)

		return

	if (IS_ERR_OR_NULL(priv->clk))

		return;



	of_clk_del_provider(spi->dev.of_node);

	clk_unregister(priv->clk);