Re: [PATCH 5/5] staging: r8188eu: turbo scan is always off for r8188eu

[Pavel Skripkin]

On 1/4/22 23:51, Martin Kaiser wrote:
> Hi Pavel,
>
> Thus wrote Pavel Skripkin (paskripkin@xxxxxxxxx):
>
> > It's a bit unrelated to the patch, but I found it while reviewing this. It's
> > in the same function rtl8188e_PHY_RF6052SetCckTxPower():
>
> > 89: 	u32 TxAGC[2] = {0, 0};
> > ...
> > 92	u8 *ptr;
> > ...
> > 129	for (idx1 = RF_PATH_A; idx1 <= RF_PATH_B; idx1++) {
> > 130		ptr = (u8 *)(&TxAGC[idx1]);
> > 131		for (idx2 = 0; idx2 < 4; idx2++) {
> > 132			if (*ptr > RF6052_MAX_TX_PWR)
> > 133				*ptr = RF6052_MAX_TX_PWR;
> > 134			ptr++;
> > 135		}
> > 136	}
>
>
> > What is going on here? Code just checks and writes to random place on stack
> > outside TxAGC array? I might be missing something, but it looks wrong...
>
> TxAGC is two 32-bit values, i.e. 2 x 4 Bytes. The outer loop selects a
> 32-bit array entry, the inner loop iterates over each byte of this entry
> and checks that it is <= RF6052_MAX_TX_PWR. I don't think this writes past
> the end of the TxAGC[] array.

Oh.... I should have go to sleep earlier that evening, sorry. I've 
missed, that this array is u32, but not u8.

Sorry for that noise :(




With regards,
Pavel Skripkin