Re: [PATCH v2] core: dev: don't call BUG() on bad input
From: Vasiliy Kulikov
Date: Mon Feb 14 2011 - 10:23:22 EST
Alexey,
On Mon, Feb 14, 2011 at 17:16 +0200, Alexey Dobriyan wrote:
> On Mon, Feb 14, 2011 at 4:42 PM, Vasiliy Kulikov <segoon@xxxxxxxxxxxx> wrote:
> > alloc_netdev() may be called with too long name (more that IFNAMSIZ bytes).
> > Currently this leads to BUG(). Other insane inputs (bad txqs, rxqs) and
> > even OOM don't lead to BUG(). Made alloc_netdev() return NULL, like on
> > other errors.
>
> > --- a/net/core/dev.c
> > +++ b/net/core/dev.c
> > @@ -5761,7 +5761,10 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
> > size_t alloc_size;
> > struct net_device *p;
> >
> > - BUG_ON(strlen(name) >= sizeof(dev->name));
> > + if (strnlen(name, sizeof(dev->name)) >= sizeof(dev->name)) {
> > + pr_err("alloc_netdev: Too long device name\n");
> > + return NULL;
> > + }
>
> Netdevice name isn't some random junk you get from userspace, so BUG is fine.
It IS for bluetooth, see net/bluetooth/bnep/core.c: bnep_add_connection() and
net/bluetooth/bnep/sock.c: bnep_sock_ioctl().
And txqs, txqs? Then why do not BUG() on bad txqs too? Why so
insonsistent? BUG() should be called in some critical situation, net
device creation is probably not such a thing.
Thanks,
--
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments
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