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Date: Fri, 11 Oct 2024 19:30:47 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: Justin Stitt <justinstitt@google.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>, Mathieu Desnoyers
 <mathieu.desnoyers@efficios.com>, linux-kernel@vger.kernel.org,
 linux-trace-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Kees
 Cook <kees@kernel.org>
Subject: Re: [PATCH] tracing: replace multiple deprecated strncpy with
 strscpy
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References: <20240930-strncpy-kernel-trace-trace_events_filter-c-v1-1-feed30820b83@google.com>
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On Fri, 11 Oct 2024 14:59:16 -0700
Justin Stitt <justinstitt@google.com> wrote:

> So, assuming I haven't lost your faith, I can send a v2 along the lines of:

Not yet ;-)

> 
> 1)
>   strscpy(num_buf, str + s, len + 1);
> 
>   ... or
> 2)
>   memcpy(num_buf, str + s, len);
>   num_buf[len] = 0;
> 
> And if you're wondering about option 3: "Don't change anything because
> the code works". I'd reiterate that I think it's important to replace
> bad ambiguous APIs. There are many cases where folks use strncpy() as
> a glorified memcpy because they want the padding behavior, or they use
> it on non-null terminated destinations or tons of other "misuses".
> Ambiguous code like that poses a real danger to the maintainability of
> the codebase and opens threat vectors.

I use it as a string memcpy, where it doesn't copy more than source. But I
don't care about the padding. So option 2 is fine with me.

-- Steve