Re: net/can: warning in raw_setsockopt/__alloc_pages_slowpath

[Marc Kleine-Budde]

On 12/02/2016 06:05 PM, Oliver Hartkopp wrote:
> 
> 
> On 12/02/2016 04:42 PM, Marc Kleine-Budde wrote:
>> On 12/02/2016 04:11 PM, Oliver Hartkopp wrote:
>>>
>>>
>>> On 12/02/2016 02:24 PM, Marc Kleine-Budde wrote:
>>>> On 12/02/2016 01:43 PM, Andrey Konovalov wrote:
>>>
>>>
>>>>>  [<ffffffff8369e0de>] raw_setsockopt+0x1be/0x9f0 net/can/raw.c:506
>>>>
>>>> We should add a check for a sensible optlen....
>>>>
>>>>> static int raw_setsockopt(struct socket *sock, int level, int optname,
>>>>> 			  char __user *optval, unsigned int optlen)
>>>>> {
>>>>> 	struct sock *sk = sock->sk;
>>>>> 	struct raw_sock *ro = raw_sk(sk);
>>>>> 	struct can_filter *filter = NULL;  /* dyn. alloc'ed filters */
>>>>> 	struct can_filter sfilter;         /* single filter */
>>>>> 	struct net_device *dev = NULL;
>>>>> 	can_err_mask_t err_mask = 0;
>>>>> 	int count = 0;
>>>>> 	int err = 0;
>>>>>
>>>>> 	if (level != SOL_CAN_RAW)
>>>>> 		return -EINVAL;
>>>>>
>>>>> 	switch (optname) {
>>>>>
>>>>> 	case CAN_RAW_FILTER:
>>>>> 		if (optlen % sizeof(struct can_filter) != 0)
>>>>> 			return -EINVAL;
>>>>
>>>> here...
>>>>
>>>> 		if (optlen > 64 * sizeof(struct can_filter))
>>>> 			return -EINVAL;
>>>>
>>>
>>> Agreed.
>>>
>>> But what is sensible here?
>>> 64 filters is way to small IMO.
>>>
>>> When thinking about picking a bunch of single CAN IDs I would tend to
>>> something like 512 filters.
>>
>> Ok - 64 was just an arbitrary chosen value for demonstration purposes :)
>>
> 
> :-)
> 
> Would you like to send a patch?

Yes, how many Filters? 512? Can you test, as I don't have the setup ready?

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |

Attachment: signature.asc
Description: OpenPGP digital signature