netdev - Re: BUG: while bridging Ethernet and wireless device:

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: <AANLkTi=XQ2DE==ggJHfokUE1=opDVOFxQNeqwY1xZN_8@mail.gmail.com>
Date:	Wed, 29 Dec 2010 18:12:16 +0200
From:	Tomas Winkler <tomasw@...il.com>
To:	Johannes Berg <johannes@...solutions.net>
Cc:	linux-netdev <netdev@...r.kernel.org>,
	linux-wireless <linux-wireless@...r.kernel.org>,
	YOSHIFUJI Hideaki / 吉藤英明 
	<yoshfuji@...ux-ipv6.org>
Subject: Re: BUG: while bridging Ethernet and wireless device:

2010/12/29 Johannes Berg <johannes@...solutions.net>:
> On Thu, 2010-12-16 at 14:11 +0200, Tomas Winkler wrote:
>> Will be happy if someone can give me some more insight. (kernel 2.6.37-rc5)
>
> Tomas looked into it a bit more and told me that it happens on IPv6
> packets. To recap, he gets
>
> kernel BUG at include/linux/skbuff.h:1178!
> with
> EIP: [<f83edd65>] br_multicast_rcv+0xc95/0xe1c [bridge]
>
> Also remember that the packets are almost fully nonlinear, when they get
> here they likely have almost no data in the skb header.
>
> I then looked at br_multicast_ipv6_rcv(), and it looks fishy:
>
> Up to:
>        skb2 = skb_clone(skb, GFP_ATOMIC);
>
> everything's fine, since ipv6_skip_exthdr() will use
> skb_header_pointer(). At this point, offset is the result of
> ipv6_skip_exthdr(). Remember that skb_clone() is not skb_copy().

So far I can confirm that switching to sbk_copy fixes the crash.

Thanks
Tomas
--
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