netdev - Re: mac80211 truesize bugs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20080501.025635.216053297.davem@davemloft.net>
Date:	Thu, 01 May 2008 02:56:35 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	johannes@...solutions.net
Cc:	mb@...sch.de, netdev@...r.kernel.org,
	linux-wireless@...r.kernel.org
Subject: Re: mac80211 truesize bugs

From: Johannes Berg <johannes@...solutions.net>
Date: Thu, 01 May 2008 11:48:19 +0200

> > Signed-off-by: David S. Miller <davem@...emloft.net>
>  
> > +	/* This is safe because the buffer has been orphaned.  */
> > +	skb->truesize += sizeof(*rthdr);
> 
> Hmm. The disconnect between truesize and skb->len+sizeof(*skb) was
> usually 17 or 19 bytes and sizeof(*rthdr) is only 11. On the other hand,
> I don't see where the other bytes should be coming from. I'll give this
> a try, thanks.

Grrr, I bet it's coming from a combination of the
skb_set_mac_header(skb, 0); call done by mac80211 and the skb_push()
calls in net/packet/af_packet.c

davem@...set:~/src/GIT/net-2.6$ egrep skb_push net/packet/af_packet.c
	skb_push(skb, skb->data - skb_mac_header(skb));
			skb_push(skb, skb->data - skb_mac_header(skb));
			skb_push(skb, skb->data - skb_mac_header(skb));
davem@...set:~/src/GIT/net-2.6$ 
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html