linux-kernel - Re: [PATCH net-next] net/rds: Replace deprecated strncpy() with strscpy

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CCF15545-8AF8-40A8-917C-E44B6373D9AE@kernel.org>
Date: Thu, 20 Feb 2025 00:54:38 -0800
From: Kees Cook <kees@...nel.org>
To: Thorsten Blum <thorsten.blum@...ux.dev>
CC: Allison Henderson <allison.henderson@...cle.com>,
 "David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>,
 Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
 Simon Horman <horms@...nel.org>, linux-hardening@...r.kernel.org,
 netdev@...r.kernel.org, linux-rdma@...r.kernel.org, rds-devel@....oracle.com,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH net-next] net/rds: Replace deprecated strncpy() with strscpy_pad()

On February 19, 2025 11:04:18 PM PST, Thorsten Blum <thorsten.blum@...ux.dev> wrote:
>On 20. Feb 2025, at 03:57, Kees Cook wrote:
>> On Wed, Feb 19, 2025 at 11:47:31PM +0100, Thorsten Blum wrote:
>>> strncpy() is deprecated for NUL-terminated destination buffers. Use
>>> strscpy_pad() instead and remove the manual NUL-termination.
>> 
>> When doing these conversions, please describe two aspects of
>> conversions:
>> 
>> - Why is it safe to be NUL terminated
>> - Why is it safe to be/not-be NUL-padded
>> 
>> In this case, the latter needs examination. Looking at how ctr is used,
>> it is memcpy()ed later, which means this string MUST be NUL padded or it
>> will leak stack memory contents.
>> 
>> So, please use strscpy_pad() here. :)
>
>I am using strscpy_pad() here already because of the NUL-padding.
>
>Did you just miss that?

Well that's embarrassing. Yes, I must need stronger glasses. *sigh* Apologies for the noise!

Reviewed-by: Kees Cook <kees@...nel.org>

-- 
Kees Cook