netdev - Re: [RFC PATCH] af_packet: don't to defrag shared skb

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]

Date:	Fri, 07 Dec 2012 22:41:42 +0100
From:	Johannes Berg <johannes@...solutions.net>
To:	David Miller <davem@...emloft.net>
Cc:	eric@...it.org, netdev@...r.kernel.org,
	linux-wireless@...r.kernel.org, linville@...driver.com
Subject: Re: [RFC PATCH] af_packet: don't to defrag shared skb

On Fri, 2012-12-07 at 22:30 +0100, Johannes Berg wrote:

> The only other theory I can come up with right now is that the skb_get()
> happens in deliver_skb via __netif_receive_skb. Keeping in mind that
> wpa_supplicant might have another packet socket open for authentication
> packets, that seems like a possibility. I'll test it once I figure out
> how to do this "defrag" option you speak of :)

Hmm now I'm venturing into the unknown (for me) and realm of
speculation...

wpa_supplicant opens a packet socket for ETH_P_EAPOL, which indirectly
eventually calls dev_add_pack(). But if you do the same for another
socket, you'll get the same again, and then deliver_skb() will deliver
only a refcounted packet to the prot_hook->func().

This seems like it could very well cause the problem?

johannes

--
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