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: ded845a781a5 ("ieee802154: Add CA8210 IEEE 802.15.4 device driver")
Signed-off-by: Dinghao Liu
---
Changelog:
v2: -Remove the first clk_unregister() instead of nulling priv->clk.
v3: -Simplify ca8210_register_ext_clock().
-Add a ';' after return in ca8210_unregister_ext_clock().
v4: -Remove an unused variable 'ret'.
---
drivers/net/ieee802154/ca8210.c | 17 +++--
1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/drivers/net/ieee802154/ca8210.c b/drivers/net/ieee802154/ca8210.c
index aebb19f1b3a4..4ec0dab38872 100644
--- a/drivers/net/ieee802154/ca8210.c
+++ b/drivers/net/ieee802154/ca8210.c
@@ -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(>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(
- >dev,
- "Failed to register external clock as clock provider\n"
- );
- } else {
- dev_info(>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);
--
2.17.1
