netdev - Re: [PATCH net-next v2 6/6] net: dsa: factor skb freeing on xmit

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: <87y3tchouh.fsf@weeman.i-did-not-set--mail-host-address--so-tickle-me>
Date:   Wed, 31 May 2017 14:18:30 -0400
From:   Vivien Didelot <vivien.didelot@...oirfairelinux.com>
To:     Florian Fainelli <f.fainelli@...il.com>, netdev@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, kernel@...oirfairelinux.com,
        "David S. Miller" <davem@...emloft.net>,
        Andrew Lunn <andrew@...n.ch>
Subject: Re: [PATCH net-next v2 6/6] net: dsa: factor skb freeing on xmit

Hi Florian,

Florian Fainelli <f.fainelli@...il.com> writes:

> On 05/30/2017 11:33 AM, Vivien Didelot wrote:
>> The taggers are currently responsible to free the original SKB if they
>> made a copy of it, or in case of error.
>> 
>> This patch simplifies this by freeing the original SKB in the
>> dsa_slave_xmit caller, but only if an error (NULL) is returned.
>
> Is not it a clearer contract if the tagging protocol must always free
> the original SKB, whether it succeeded in creating a new one or not?

The rcv caller frees the original SKB on error, as of a86d8becc3f0
("net: dsa: Factor bottom tag receive functions").

It'd be nice if we could make both xmit and rcv symmetric, and limit the
tagging implementations to only do their real job: tag/untag an SKB with
the destination/source port.

Thanks,

        Vivien