netdev - Re: [PATCH] flex_can: Fix checking can

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: <24ad57a6-bee8-1dad-8e74-7f68918aa81e@hartkopp.net>
Date:   Mon, 25 Dec 2017 12:58:56 +0100
From:   Oliver Hartkopp <socketcan@...tkopp.net>
To:     Luu An Phu <phu.luuan@....com>, wg@...ndegger.com,
        mkl@...gutronix.de
Cc:     linux-can@...r.kernel.org, netdev@...r.kernel.org,
        stefan-gabriel.mirea@....com
Subject: Re: [PATCH] flex_can: Fix checking can_dlc

Answering myself after reading my own comment once more:

In fact the code fix seems to be correct but the commit comment was 
completely wrong which lead to my answer ...

can_dlc can hold values from 0 .. 8.

The first 4 bytes are placed in data[0..3]. When we have more(!) than 4 
bytes in can_dlc, the bytes 5..8 are placed in data[4..7].

The good thing was, that the current check was more conservative than 
your suggestion so that we did not detect any data loss.

Please send a V2 patch with corrected commit message.

Thanks,
Oliver

ps.

>> From: "phu.luuan" <phu.luuan@....com>
>> + * Copyright 2017 NXP

A one-liner contribution like this tiny fix usually does not lead to an 
attribution in the copyrights. Your contribution is already perfectly 
recorded by the Signed-off-by tag.