Re: [PATCH 2/2] staging: rtl8192e: Change state information from u16 to u8

Greg KH
2021-02-21T13:09:13Z

On Sat, Feb 20, 2021 at 11:51:55PM +0530, Atul Gopinathan wrote:
> The "CcxRmState" field in struct "rtllib_network" is defined
> as a u16 array of size 2 (so, 4 bytes in total).
>
> But the operations performed on this array throughout the code
> base (in rtl8192e/) are all in byte size 2 indicating that this
> array's type was defined wrongly.
>
> There are two situation were u16 type of this field could yield
> incorrect behaviour:
>
> 1. In rtllib_rx.c:1970:
> memcpy(network->CcxRmState, &info_element->data[4], 2);
>
> Here last 2 bytes (index 4 and 5) from the info_element->data[]
> array are meant to be copied into CcxRmState[].
> Note that "data" array here is an array of type u8.
>
> 2. In function "update_network()" in staging/rtl8192e/rtllib_rx.c:
> memcpy(dst->CcxRmState, src->CcxRmState, 2);
>
> Here again, only 2 bytes are copied from the source state to
> destination state.
>
> There are no instances of "CcxRmState" requiring u16 data type.
> Here is the output of "grep -IRn 'CcxRmState'" on the rtl8192e/
> directory for reviewing:
>
> rtllib_rx.c:1970: memcpy(network->CcxRmState, &info_element->data[4], 2);
> rtllib_rx.c:1971: if (network->CcxRmState[0] != 0)
> rtllib_rx.c:1975: network->MBssidMask = network->CcxRmState[1] & 0x07;
> rtllib_rx.c:2520: memcpy(dst->CcxRmState, src->CcxRmState, 2);
> rtllib.h:1108: u8 CcxRmState[2];

You just changed the logic in line 1975 in that file, right? Are you
_SURE_ that is ok? Do you have a device to test this on?

thanks,

greg k-h