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

Samuel Holland
2023-02-12T21:11:30Z

On 2/9/23 16:49, Alexandre Belloni wrote:
> Hello,
>
> What should I do with this series, I'm not sure you came to an
> agreement.
> Also, 2/2 doesn't apply so you'd have to rebase.

I will send v2 after the merge window, possibly including only patch 2.

Regards,
Samuel

> On 29/12/2022 12:40:10-0600, Samuel Holland wrote:
>> 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
>>
>