[0/7] [PPP]: Fix shared/cloned/non-linear skb bugs (was: malformed captured packets)
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: 2007-08-31 09:07:13
On Thu, Aug 30, 2007 at 09:51:31AM +0000, James Chapman wrote:
The captured PPPoE stream seems to show incorrect data lengths in the PPPoE header for some captured PPPoE packets. The kernel's PPPoE datapath uses this length to extract the PPP frame and send it through to the ppp interface. Since your ppp stream is fine, the actual PPPoE header contents must be correct when it is parsed by the kernel PPPoE code. It seems more likely that this is a wireshark bug to me.
If he were using the kernel pppoe driver, then this is because PPP filtering is writing over a cloned skb without copying it. In fact, there seems to be quite a few bugs of this kind in the various ppp*.c files. Please try the following patches to see if they make a difference. I've audited ppp_generic.c and pppoe.c. I'll do pppol2tp tomorrow. Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} [off-list ref] Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt