On 19-7-2016 18:42, Florian Fainelli wrote:
> On 07/19/2016 03:38 AM, Arend Van Spriel wrote:
>> On 19-7-2016 1:24, Florian Fainelli wrote:
>>> struct ieee80211_rts::ra is only ETH_ALEN wide, yet we attempt to copy 2
>>> * ETH_ALEN, which will potentially overrun the destination buffer.
>>
>> NACK - this is intentional. Have to admit it is a bit of trickery.
>
> This seems fragile, if there is any kind of re-ordering of fields within
> that structure your trick breaks apart.
Well, that would be an 802.11 standard update and given that it would
break legacy devices I think it is unlikely that reordering would happen
in this case.
>> struct ieee80211_rts is mapped over struct d11txh which is sent to
>> hardware. The struct is used for both RTS and CTS. Transmitting CTS will
>> only fill 802.11 addr2 in struct ieee80211_rts::ra. Transmitting RTS
>> fills 802.11 addr1 in ra and 802.11 addr2 in ta using single memcpy().
>> Not very clear, but your change is not the way to go here.
>
> Fair enough, as Kalle suggested, this deserves a comment explaining why,
> I would not be surprised other people would trip over that.
Agree. I am also fine with two separate memcpy() statements if that
gives enough clarification.
Regards,
Arend
>>
>> Regards,
>> Arend
>>
>>> Reported-by: coverity (CID 145657)
>>> Fixes: 5b435de0d7868 ("net: wireless: add brcm80211 drivers")
>>> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
>>> ---
>>> drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c
>>> index c2a938b59044..59813a3666eb 100644
>>> --- a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c
>>> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c
>>> @@ -6671,7 +6671,7 @@ brcms_c_d11hdrs_mac80211(struct brcms_c_info *wlc, struct ieee80211_hw *hw,
>>> rts->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
>>> IEEE80211_STYPE_RTS);
>>>
>>> - memcpy(&rts->ra, &h->addr1, 2 * ETH_ALEN);
>>> + memcpy(&rts->ra, &h->addr1, ETH_ALEN);
>>> }
>>>
>>> /* mainrate
>>>
>
>
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