clk: Check parent for NULL in clk_change_rate
commit bf47b4fd8f9f81cd5ce40e1945c6334d088226d1 upstream.
clk_change_rate() is accessing parent's rate without checking
if the parent exists at all. In case of root clocks this will
cause NULL pointer dereference.
This patch follows what clk_calc_new_rates() does in such
situation.
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 2da025e..7f1ea56 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -834,18 +834,21 @@
{
struct clk *child;
unsigned long old_rate;
+ unsigned long best_parent_rate = 0;
struct hlist_node *tmp;
old_rate = clk->rate;
+ if (clk->parent)
+ best_parent_rate = clk->parent->rate;
+
if (clk->ops->set_rate)
clk->ops->set_rate(clk->hw, clk->new_rate);
if (clk->ops->recalc_rate)
- clk->rate = clk->ops->recalc_rate(clk->hw,
- clk->parent->rate);
+ clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate);
else
- clk->rate = clk->parent->rate;
+ clk->rate = best_parent_rate;
if (clk->notifier_count && old_rate != clk->rate)
__clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);