On Fri, Mar 5, 2010 at 6:14 AM, Dan Carpenter <error27@xxxxxxxxx> wrote:
> So here is a mystery for people who enjoy such mysterious things.
>
> drivers/staging/rt2860/sta_ioctl.c +1020 rt_ioctl_giwscan(219)
> 1011 if (CAP_IS_PRIVACY_ON
> 1012 (pAdapter->ScanTab.BssEntry[i].CapabilityInfo))
> 1013 iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
> 1014 else
> 1015 iwe.u.data.flags = IW_ENCODE_DISABLED;
> 1016
> 1017 __smatch_value("iwe.u.data.flags");
> 1018 previous_ev = current_ev;
> 1019 current_ev =
> 1020 iwe_stream_add_point(info, current_ev, end_buf, &iwe,
> 1021 (char *)pAdapter->
> 1022 SharedKey[BSS0][(iwe.u.data.
> 1023 flags &
> 1024 IW_ENCODE_INDEX) -
> 1025 1].Key);
>
>
> That last bit is easier to read if it's on one line.
>
> SharedKey[BSS0][(iwe.u.data.flags & IW_ENCODE_INDEX) - 1].Key);
>
> iwe.u.data.flags is either 0x0400 or 0x8000. IW_ENCODE_INDEX is 0xff, so
> after we mask off the lower bits we get 0x00 and then we subtract 1 we get
> an array offset of -1.
>
> I doubt that's what we want, but what _do_ we want here?
>
Looking at the use of IW_ENCODE_INDEX elsewhere it seems to be a mask
for a key value that can be 0..4 where 0 means some default value and
1 - 4 means use value-- ie 0 - 3.
iwe.u.data.flags is assigned to 1 earlier so I would assume the code should be
iwe.u.data.flags &= ~ IW_ENCODE_FLAGS
>> 1011 if (CAP_IS_PRIVACY_ON
>> 1012 (pAdapter->ScanTab.BssEntry[i].CapabilityInfo))
>> 1013 iwe.u.data.flags |= IW_ENCODE_ENABLED | IW_ENCODE_NOKEY;
>> 1014 else
>> 1015 iwe.u.data.flags |= IW_ENCODE_DISABLED;
Which I think would both make sense and give an array index of 0.
Darren J.
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