RE: [PATCH] input: spi: Driver for SPI data stream driven vibrator

[ilkka.koskinen]

>From: ext Alan Cox [mailto:alan@xxxxxxxxxxxxxxxxxxx]
>Sent: 08 November, 2010 13:39
>
>On Mon, 8 Nov 2010 12:08:07 +0100
><ilkka.koskinen@xxxxxxxxx> wrote:
>
>> Hi,
>>
>> >From: ext Alan Cox [mailto:alan@xxxxxxxxxxxxxxxxxxx]
>> >Sent: 08 November, 2010 01:52
>> >
>> >> +	datalen = p->custom_len * sizeof(p->custom_data[0]);
>> >
>> >signed
>> >
>> >> +	if (datalen > MAX_EFFECT_SIZE) {
>> >
>> >unsigned
>>
>> It should be unsigned. I'll fix it.
>>
>> >> +	memcpy(einfo->buf, p->custom_data, datalen);
>> >
>> >ungood
>>
>> Yep, that's clearly wrong too. Should be copy_from_user() I suppose.
>
>That I hadn't considered - and I'm not sure whether the caller is passed
>a kernel copy or not. The problem I was looking at was just the signed
>case
>
>	datalen < 0
>	if (datalen > MAX ..)
>		Nope
>
>	memcpy(kernel, mysource, vastly more than intended (unsigned))

Ah, I got it now. Thanks for clarification :) 

Cheers, Ilkka

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