From: Alexander Lobakin <aleksander.lobakin@intel.com>
To: Kees Cook <kees@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>,
Masahiro Yamada <masahiroy@kernel.org>,
Nicolas Schier <nicolas.schier@linux.dev>,
<linux-kbuild@vger.kernel.org>,
Nick Desaulniers <nick.desaulniers+lkml@gmail.com>,
Bill Wendling <morbo@google.com>,
"Justin Stitt" <justinstitt@google.com>,
<linux-kernel@vger.kernel.org>, <llvm@lists.linux.dev>,
<linux-hardening@vger.kernel.org>
Subject: Re: [PATCH v2] kbuild: Re-enable -Wunterminated-string-initialization
Date: Mon, 11 Aug 2025 16:25:26 +0200 [thread overview]
Message-ID: <3fd91204-629f-4024-8d49-c76c7b344735@intel.com> (raw)
In-Reply-To: <202508071458.A97B471@keescook>
From: Kees Cook <kees@kernel.org>
Date: Thu, 7 Aug 2025 15:00:24 -0700
> On Thu, Aug 07, 2025 at 03:31:05PM +0200, Alexander Lobakin wrote:
>> Sure, lots of drivers uses normal string copy functions etc.
>> But Ethtool strings *must* be NUL-terminated, so this fixed-size +
>> memcpy() only hurts.
>
> This is the misunderstanding: they're only NUL padded, but not strictly
> NUL terminated. You can see ethtool itself has to be careful with the
> strings, limiting the fprintf to their sizeof():
>
> https://git.kernel.org/pub/scm/network/ethtool/ethtool.git/tree/ethtool.c#n1013
>
> or using strncmp everywhere.
Maybe we should add a check to the Ethtool core that every 32-th array
symbol == \0 to detect misbehaving drivers like this one :D
Thanks,
Olek
next prev parent reply other threads:[~2025-08-11 14:27 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-02 18:43 Kees Cook
2025-08-03 17:32 ` Nathan Chancellor
2025-08-05 14:50 ` Alexander Lobakin
2025-08-05 21:48 ` Nathan Chancellor
2025-08-06 15:29 ` Alexander Lobakin
2025-08-06 19:05 ` Kees Cook
2025-08-07 13:31 ` Alexander Lobakin
2025-08-07 22:00 ` Kees Cook
2025-08-11 14:25 ` Alexander Lobakin [this message]
2025-09-05 15:59 ` Kees Cook
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