commit 6579c8d97ad7 ("clk: Mark fwnodes when their clock provider is added")
revealed that clk/bcm/clk-raspberrypi.c driver calls
devm_of_clk_add_hw_provider(), with a NULL dev->of_node, which resulted in a
NULL pointer dereference in of_clk_add_hw_provider() when calling
fwnode_dev_initialized().
Returning 0 is reducing the if conditions in driver code and is being
consistent with the CONFIG_OF=n inline stub that returns 0 when CONFIG_OF
is disabled. The downside is that drivers will maybe register clkdev lookups
when they don't need to and waste some memory.
Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Fixes: 6579c8d97ad7 ("clk: Mark fwnodes when their clock provider is added")
Fixes: 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is added/removed")
Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
Reviewed-by: Stephen Boyd <sboyd@xxxxxxxxxx>
---
v2:
- s/return 0;/return; in void of_clk_del_provider()
- add second fixes tag and Stephen's R-b tag
The opinions on whether to return an error or zero were split. Returning 0
and skipping the logic was considered safer as we don't know for sure if
other drivers are affected. See:
https://lore.kernel.org/lkml/d24bebc5-0f78-021f-293f-e58defa32531@xxxxxxxxxxx/
https://lore.kernel.org/lkml/20210423171335.262316-1-tudor.ambarus@xxxxxxxxxxxxx/
drivers/clk/clk.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index a3b30f7de2ef..b47460b40d14 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -4552,6 +4552,9 @@ int of_clk_add_provider(struct device_node *np,
struct of_clk_provider *cp;
int ret;
+ if (!np)
+ return 0;
+
cp = kzalloc(sizeof(*cp), GFP_KERNEL);
if (!cp)
return -ENOMEM;
@@ -4591,6 +4594,9 @@ int of_clk_add_hw_provider(struct device_node *np,
struct of_clk_provider *cp;
int ret;
+ if (!np)
+ return 0;
+
cp = kzalloc(sizeof(*cp), GFP_KERNEL);
if (!cp)
return -ENOMEM;
@@ -4688,6 +4694,9 @@ void of_clk_del_provider(struct device_node *np)
{
struct of_clk_provider *cp;
+ if (!np)
+ return;
+
mutex_lock(&of_clk_mutex);
list_for_each_entry(cp, &of_clk_providers, link) {
if (cp->node == np) {
--
2.25.1
