[Xenial][PATCH 1/2] net/wireless: do not dereference invalid pointer

[Colin Ian King]

On 24/08/17 09:43, Jesse Sung wrote:
> 2017-08-24 16:36 GMT+08:00 Colin Ian King <colin.king at canonical.com>:
>> On 24/08/17 08:30, Wen-chien Jesse Sung wrote:
>>> BugLink: https://launchpad.net/bugs/1712746
>>>
>>> The wiphy may be NULL sometimes. Do not dereference when it's NULL.
>>>
>>> Signed-off-by: Wen-chien Jesse Sung <jesse.sung at canonical.com>
>>> ---
>>>  net/wireless/util.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/net/wireless/util.c b/net/wireless/util.c
>>> index baf7218..e358511 100644
>>> --- a/net/wireless/util.c
>>> +++ b/net/wireless/util.c
>>> @@ -121,7 +121,7 @@ struct ieee80211_channel *__ieee80211_get_channel(struct wiphy *wiphy,
>>>       int i;
>>>
>>>       for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
>>> -             sband = wiphy->bands[band];
>>> +             sband = wiphy ? wiphy->bands[band] : NULL;
>>>
>>>               if (!sband)
>>>                       continue;
>>>
>>
>> I am curious why wiphy can be null, is there some underlying bug
>> somewhere else that is the root cause than needs fixing rather than
>> papering over the issue with these workarounds?
> 
> Most likely it's a bug in mwifiex... We've already pinged Marvell and Murata.
> These workarounds can be a temporary solution until there's a real fix.

OK, sounds good to me. Thanks Jesse.
> 
>>
>> Colin