netdev - Re: [PATCH net v2] net: bridge: Fix ethernet header pointer before check skb forwardable

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:   Tue, 15 Jan 2019 12:21:56 +0300
From:   Sergei Shtylyov <sergei.shtylyov@...entembedded.com>
To:     wangyunjian <wangyunjian@...wei.com>, netdev@...r.kernel.org
Cc:     xudingke@...wei.com, bridge@...ts.linux-foundation.org,
        Nkolay Aleksandrov <nikolay@...ulusnetworks.com>,
        Roopa Prabhu <roopa@...ulusnetworks.com>
Subject: Re: [PATCH net v2] net: bridge: Fix ethernet header pointer before
 check skb forwardable

On 15.01.2019 6:12, wangyunjian wrote:

> From: Yunjian Wang <wangyunjian@...wei.com>
> 
> The skb header should be set to ethernet header before using
> is_skb_forwardable. Because the ethernet header length has been
> considered in is_skb_forwardable(including dev->hard_header_len
> length).
> 
> To reproduce the issue:
> 1, add 2 ports on linux bridge br using following commands:
> $ brctl addbr br
> $ brctl addif br eth0
> $ brctl addif br eth1
> 2, the mtu of eth0 and eth1 is 1500
> 3, send a 1504 packet from eth0 to eth1
> 
> So the expect result is packet larger than 1500 cannot pass through
> eth0 and eth1. But currently, the packet passes through success, it
> means eth1's mtu limit donen't take effect.

    Doesn't. And MTU.

> Fixes: f6367b4660dd ("bridge: use is_skb_forwardable in forward path")
> Cc: bridge@...ts.linux-foundation.org
> Cc: Nkolay Aleksandrov <nikolay@...ulusnetworks.com>
> Cc: Roopa Prabhu <roopa@...ulusnetworks.com>
> Signed-off-by: Yunjian Wang <wangyunjian@...wei.com>
[...]

MBR, Sergei