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Date:   Fri, 8 Sep 2023 11:18:32 +0100
From:   Will Deacon <will@kernel.org>
To:     Justin Stitt <justinstitt@google.com>
Cc:     Konrad Dybcio <konradybcio@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Mostafa Saleh <smostafa@google.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Kees Cook <keescook@chromium.org>,
        linux-hardening@vger.kernel.org
Subject: Re: [PATCH v4] arm64/sysreg: refactor deprecated strncpy
Message-ID: <20230908101831.GA6849@willie-the-truck>
References: <20230905-strncpy-arch-arm64-v4-1-bc4b14ddfaef@google.com>
 <f08f590a-df05-4d83-984f-41b4d60af971@kernel.org>
 <CAFhGd8pMeTuvn_OqzYtRbfAM7L_-Jb_hFA4WY0hMap_eG=F7RA@mail.gmail.com>
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On Thu, Sep 07, 2023 at 11:17:08AM -0700, Justin Stitt wrote:
> On Thu, Sep 7, 2023 at 10:37 AM Konrad Dybcio <konradybcio@kernel.org> wrote:
> >
> >
> >
> > On 5.09.2023 22:10, Justin Stitt wrote:
> > > strncpy is deprecated [1] and should not be used if the src string is
> > > not NUL-terminated.
> > >
> > > When dealing with `cmdline` we are counting the number of characters
> > > until a space then copying these over into `buf`. Let's not use any of
> > > the str*() functions since the src string is not necessarily NUL-terminated.
> > >
> > > Prefer `memcpy()` alongside a forced NUL-termination as it more
> > > accurately describes what is going on within this function, i.e: copying
> > > from non NUL-terminated buffer into a NUL-terminated buffer.
> > >
> > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> > > Link: https://github.com/KSPP/linux/issues/90
> > > Cc: linux-hardening@vger.kernel.org
> > > Suggested-by: Kees Cook <keescook@chromium.org>
> > > Signed-off-by: Justin Stitt <justinstitt@google.com>
> > > ---
> > Hi,
> >
> > some form of this patch [1] went into -next and it broke booting
> > on at least the Qualcomm SC8280XP-based Lenovo Thinkpad X13S.
> >
> 
> Thanks for the heads up! The previous versions of the patch (including
> the one that was applied) had some errors. This patch should be good
> and Will is looking to apply it to arm64 fixes tree.

Yes, it should be fixed in linux-next 20230908.

Cheers,

Will