linux-kernel - Re: [PATCH net-next 11/12] ipvlan: Ignore PACKET_LOOPBACK in handle_mode

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] [day] [month] [year] [list]

Message-ID: <41b025b6-1675-4318-b98c-4d5435a771a7@huawei.com>
Date: Tue, 2 Dec 2025 13:08:44 +0300
From: Dmitry Skorodumov <skorodumov.dmitry@...wei.com>
To: Paolo Abeni <pabeni@...hat.com>, <netdev@...r.kernel.org>, Jakub Kicinski
	<kuba@...nel.org>, Ido Schimmel <idosch@...dia.com>, Eric Dumazet
	<edumazet@...gle.com>, Julian Vetter <julian@...er-limits.org>, Guillaume
 Nault <gnault@...hat.com>, <linux-kernel@...r.kernel.org>
CC: <andrey.bokhanko@...wei.com>, Andrew Lunn <andrew+netdev@...n.ch>, "David
 S. Miller" <davem@...emloft.net>
Subject: Re: [PATCH net-next 11/12] ipvlan: Ignore PACKET_LOOPBACK in
 handle_mode_l2()


On 25.11.2025 17:30, Paolo Abeni wrote:
> On 11/20/25 6:49 PM, Dmitry Skorodumov wrote:
>> Packets with pkt_type == PACKET_LOOPBACK are captured by
>> handle_frame() function, but they don't have L2 header.
>> We should not process them in handle_mode_l2().
>>
>> This doesn't affect old L2 functionality, since handling
>> was anyway incorrect.
>>
>> Handle them the same way as in br_handle_frame():
>> just pass the skb.
>>
>> To observe invalid behaviour, just start "ping -b" on bcast address
>> of port-interface.
>>
>> Signed-off-by: Dmitry Skorodumov <skorodumov.dmitry@...wei.com>
> Again, this looks like a fix suitable for 'net'.
>
> Also the condition described above looks easily reproducible, you should
> add a specific self-test.

Hm... I'm not sure how to invent a self-test for this (and tests for ipvlan appears only after this series). It is just an SKB without ETH-header and it just flows through functions in the module - where each of the functions treats data of IP-header as ETH

The issue seems quite obvious - i hope it's ok if I send this patch separately - but without tests so far

Dmitry