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From: Azeem Shaikh <azeemshaikh38@gmail.com>
To: David Laight <David.Laight@aculab.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"linux-hardening@vger.kernel.org"
	<linux-hardening@vger.kernel.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] kobject: Replace strlcpy with strscpy
Date: Mon, 10 Jul 2023 14:06:44 -0400	[thread overview]
Message-ID: <CADmuW3XOcGDBszYw80Dy03DXk3T25k8FNUrJWLKU9tL2znzanw@mail.gmail.com> (raw)
In-Reply-To: <ad25bb8552704028860cf7a419c54fa3@AcuMS.aculab.com>

On Mon, Jul 10, 2023 at 9:13 AM David Laight <David.Laight@aculab.com> wrote:
>
> >       int len;
> >
> > -     len = strlcpy(&env->buf[env->buflen], subsystem, buffer_size);
> > -     if (len >= buffer_size) {
> > +     len = strscpy(&env->buf[env->buflen], subsystem, buffer_size);
> > +     if (len < 0) {
> >               pr_warn("init_uevent_argv: buffer size of %d too small, needed %d\n",
> >                       buffer_size, len);
> >               return -ENOMEM;
>
> The size in the error message is now wrong.

Thanks for catching this.

> It has to be said that mostly all the strings that get copied
> in the kernel are '\0' terminated - so maybe it is all moot.
> OTOH printing (at least some of) the string that didn't fit
> is a lot more useful than its length.

How about printing out strlen(subsystem) along with the entire value
of @subsystem? So that the warn reads:

pr_warn("init_uevent_argv: buffer size of %d too small for %s, needed
%d\n", buffer_size, subsystem, strlen(subsystem));

Does that seem better?

  reply	other threads:[~2023-07-10 18:06 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-03 18:05 [PATCH] kobject: Replace strlcpy with strscpy Azeem Shaikh
2023-07-10 13:13 ` David Laight
2023-07-10 18:06   ` Azeem Shaikh [this message]
2023-07-11  8:14     ` David Laight
2023-07-12 23:52       ` Kees Cook
2023-07-13  8:18         ` David Laight

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