Re: Fwd: Possible bug in net/ipv4/route.c?

Le lundi 05 juillet 2010 à 17:07 -0300, Henrique de Moraes Holschuh a
écrit :

On Mon, 05 Jul 2010, Eric Dumazet wrote:

quoted

Le lundi 05 juillet 2010 à 21:22 +0800, Herbert Xu a écrit :

quoted

On Mon, Jul 05, 2010 at 02:59:14PM +0200, Eric Dumazet wrote:

quoted

Why do we clear full 48 bytes skb->cb[] in skb_alloc(), if no protocol
stack should rely it being zero ?

Unless a protocol is allocating the skb itself, then the fact
that skb_alloc clears skb->cb is no guarantee that the skb->cb
will be zero.

I see. We could :

Avoid this memset(skb->cb, 0, sizeof(skb->cb)) in fastpath.

Any chances of skb->cb being leaked to userspace or the network, due to
driver bugs or other such oddities?

Not "a priori", but a bug is always possible ;)

cb[] is internal use only, should not be sent to network or user land.