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 Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
Attachment:
signature.asc
Description: PGP signature
