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References: <20240206142027.make.107-kees@kernel.org> <20240206142221.2208763-4-keescook@chromium.org>
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From: Andy Shevchenko <andy.shevchenko@gmail.com>
Date: Tue, 6 Feb 2024 17:02:16 +0200
Message-ID: <CAHp75Vf3c0Q7tV8ih5fRL6Bsjr6dhspFe+mxV7xUN=vZ1JdTKQ@mail.gmail.com>
Subject: Re: [PATCH v3 4/4] um: Convert strscpy() usage to 2-argument style
To: Kees Cook <keescook@chromium.org>
Cc: Andy Shevchenko <andy@kernel.org>, Richard Weinberger <richard@nod.at>, linux-um@lists.infradead.org, 
	Justin Stitt <justinstitt@google.com>, Anton Ivanov <anton.ivanov@cambridgegreys.com>, 
	Johannes Berg <johannes@sipsolutions.net>, 
	Willem de Bruijn <willemdebruijn.kernel@gmail.com>, Jason Wang <jasowang@redhat.com>, 
	kernel test robot <lkp@intel.com>, Nathan Chancellor <nathan@kernel.org>, 
	Azeem Shaikh <azeemshaikh38@gmail.com>, linux-kernel@vger.kernel.org, 
	linux-hardening@vger.kernel.org
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On Tue, Feb 6, 2024 at 4:22=E2=80=AFPM Kees Cook <keescook@chromium.org> wr=
ote:
>
> The ARCH=3Dum build has its own idea about strscpy()'s definition. Adjust
> the callers to remove the redundant sizeof() arguments ahead of treewide
> changes, since it needs a manual adjustment for the newly named
> sized_strscpy() export.

..

> -               strscpy(dir, home, sizeof(dir));
> +               strscpy(dir, home);
>                 uml_dir++;
>         }
>         strlcat(dir, uml_dir, sizeof(dir));

An (unrelated) side note: are we going to get rid of strlcat() as well
(after strlcpy() is gone)?

..

>         if (*umid =3D=3D '\0') {
> -               strscpy(tmp, uml_dir, sizeof(tmp));
> +               strscpy(tmp, uml_dir);
>                 strlcat(tmp, "XXXXXX", sizeof(tmp));

This code is interesting... (Esp. taking into account making a
temporary folder out of this...)

--=20
With Best Regards,
Andy Shevchenko