[PATCH 1/2] rtc: sun6i: Prevent an out-of-bounds read

Samuel Holland
2022-12-29T18:40:40Z

If there is more than one parent clock in the devicetree, the
driver sets .num_parents to a larger value than the number of array
elements, which causes an out-of-bounds read in the clock framework.

Fix this by coercing the parent count to a Boolean value, like the
driver expects.

Fixes: 3855c2c3e546 ("rtc: sun6i: Expose the 32kHz oscillator")
Signed-off-by: Samuel Holland <samuel@sholland.org>
---

drivers/rtc/rtc-sun6i.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index ed5516089e9a..a22358a44e32 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -294,7 +294,7 @@ static void __init sun6i_rtc_clk_init(struct device_node *node,

init.parent_names = parents;
/* ... number of clock parents will be 1. */
- init.num_parents = of_clk_get_parent_count(node) + 1;
+ init.num_parents = !!of_clk_get_parent_count(node) + 1;
of_property_read_string_index(node, "clock-output-names", 0,
&init.name);

--
2.37.4