lkml.org 
[lkml]   [2019]   [Apr]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] leds: fix a potential NULL pointer dereference
From
Date
Hi Geert,

On 4/1/19 9:08 AM, Geert Uytterhoeven wrote:
> Hi Jacek,
>
> On Sun, Mar 31, 2019 at 1:01 PM Jacek Anaszewski
> <jacek.anaszewski@gmail.com> wrote:
>> On 3/31/19 11:06 AM, Geert Uytterhoeven wrote:
>> On Sun, Mar 10, 2019 at 9:40 PM Jacek Anaszewski
>>> <jacek.anaszewski@gmail.com> wrote:
>>>> On 3/9/19 7:04 AM, Kangjie Lu wrote:
>>>>> In case of_match_device cannot find a match, the fixes returns
>>>>> -EINVAL to avoid NULL pointer dereference.
>>>>>
>>>>> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
>>>>> ---
>>>>> drivers/leds/leds-pca9532.c | 8 ++++++--
>>>>> 1 file changed, 6 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c
>>>>> index 7fea18b0c15d..4b0335591728 100644
>>>>> --- a/drivers/leds/leds-pca9532.c
>>>>> +++ b/drivers/leds/leds-pca9532.c
>>>>> @@ -513,6 +513,7 @@ static int pca9532_probe(struct i2c_client *client,
>>>>> const struct i2c_device_id *id)
>>>>> {
>>>>> int devid;
>>>>> + const struct of_device_id *of_id;
>>>>> struct pca9532_data *data = i2c_get_clientdata(client);
>>>>> struct pca9532_platform_data *pca9532_pdata =
>>>>> dev_get_platdata(&client->dev);
>>>>> @@ -528,8 +529,11 @@ static int pca9532_probe(struct i2c_client *client,
>>>>> dev_err(&client->dev, "no platform data\n");
>>>>> return -EINVAL;
>>>>> }
>>>>> - devid = (int)(uintptr_t)of_match_device(
>>>>> - of_pca9532_leds_match, &client->dev)->data;
>>>>> + of_id = of_match_device(of_pca9532_leds_match,
>>>>> + &client->dev);
>>>>> + if (unlikely(!of_id))
>>>
>>> Use of unlikey() is frowned upon.
>>
>> What do you mean? Can you give some reference?
>
> I have more memories of this being discussed, but I could find only
> https://lwn.net/Articles/420019/

Thanks!

> It may be useful for some heavily used core code, but not in most drivers
> or uncritical code like probe paths, due to:
> - many people getting it wrong,
> - usually it doesn't make any difference at all.
>
>>>> Applied to the for-5.2 branch of linux-leds.git.
>>>
>>> And also as a fix for v5.1...
>>
>> Yes, but it had been in linux-next for almost two weeks before that.
>
> Sorry, I only noticed when it got upstream.

No problem.

--
Best regards,
Jacek Anaszewski

\
 
 \ /
  Last update: 2019-04-02 20:49    [W:0.073 / U:10.656 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site