Messages in this thread | | | Date | Wed, 11 May 2022 16:57:50 +0200 | Subject | Re: [PATCH 1/1] can: skb: add and set local_origin flag | From | Oliver Hartkopp <> |
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On 5/11/22 16:54, Marc Kleine-Budde wrote: > On 11.05.2022 16:50:06, Oliver Hartkopp wrote: >> >> >> On 5/11/22 16:36, Marc Kleine-Budde wrote: >>> On 11.05.2022 15:24:21, Marc Kleine-Budde wrote: >>>> On 11.05.2022 14:38:32, Oliver Hartkopp wrote: >>>>> IMO this patch does not work as intended. >>>>> >>>>> You probably need to revisit every place where can_skb_reserve() is used, >>>>> e.g. in raw_sendmsg(). >>>> >>>> And the loopback for devices that don't support IFF_ECHO: >>>> >>>> | https://elixir.bootlin.com/linux/latest/source/net/can/af_can.c#L257 >>> >>> BTW: There is a bug with interfaces that don't support IFF_ECHO. >>> >>> Assume an invalid CAN frame is passed to can_send() on an interface that >>> doesn't support IFF_ECHO. The above mentioned code does happily generate >>> an echo frame and it's send, even if the driver drops it, due to >>> can_dropped_invalid_skb(dev, skb). >>> >>> The echoed back CAN frame is treated in raw_rcv() as if the headroom is valid: >>> >>> | https://elixir.bootlin.com/linux/v5.17.6/source/net/can/raw.c#L138 >>> >>> But as far as I can see the can_skb_headroom_valid() check never has >>> been done. What about this patch? >>> >>> index 1fb49d51b25d..fda4807ad165 100644 >>> --- a/net/can/af_can.c >>> +++ b/net/can/af_can.c >>> @@ -255,6 +255,9 @@ int can_send(struct sk_buff *skb, int loop) >>> */ >>> if (!(skb->dev->flags & IFF_ECHO)) { >>> + if (can_dropped_invalid_skb(dev, skb)) >>> + return -EINVAL; >>> + >> >> Good point! >> >> But please check the rest of the code. >> You need 'goto inval_skb;' instead of the return ;-) > > Why? To free the skb? That's what can_dropped_invalid_skb() does, too: > > | https://elixir.bootlin.com/linux/v5.17.6/source/include/linux/can/skb.h#L130 >
My bad!
Pointing you not reading the code ... should better have looked myself :-D
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