Re: [PATCH] net: caif: Don't act on notification for non-caifdevices

From: Sasha Levin
Date: Tue Jan 24 2012 - 07:50:22 EST


On Tue, 2012-01-24 at 11:52 +0100, Sjur Brændeland wrote:
>
> Nack, we have to handle other device types than just ARPHDR_CAIF after
> introducing
> CAIF over USB/NCM. I'd rather fix this in netns by removing the BUG_ON
> and return
> NULL. How about this instead:
[snip]

I think that doing it this way is wrong for two reasons:

1. The code in net/ assumes net_generic is a trivial dereference and doesn't check that it's not NULL. This means that if anything goes wrong there you'll have a more dangerous NULL deref instead of a BUG().

2. You'll need to add other device to that if() statement anyway, as it currently looks like this:

cfg = get_cfcnfg(dev_net(dev));
caifdevs = caif_device_list(dev_net(dev));
if (!cfg || !caifdevs)
return 0;

caifd = caif_get(dev);
if (caifd == NULL && dev->type != ARPHRD_CAIF)
return 0;

What my patch did was simply move the type check to above the net_generic call, it didn't add any new checks - which according to what you said, you'll need to do anyway.

--

Sasha.

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