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Message-ID: <2f407e7c-9bc7-4915-a043-5a7cec2cb2b1@quicinc.com>
Date:   Mon, 23 Oct 2023 16:40:54 -0700
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Subject: Re: [PATCH] ath10k: replace deprecated strncpy with strtomem_pad
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To:     Kees Cook <keescook@chromium.org>
CC:     Justin Stitt <justinstitt@google.com>,
        Kalle Valo <kvalo@kernel.org>, <ath10k@lists.infradead.org>,
        <linux-wireless@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-hardening@vger.kernel.org>
References: <20231013-strncpy-drivers-net-wireless-ath-ath10k-mac-c-v1-1-24e40201afa3@google.com>
 <1cfc7c64-439c-437e-af82-7fce1202242d@quicinc.com>
 <202310181626.C5BE0C21F@keescook>
From:   Jeff Johnson <quic_jjohnson@quicinc.com>
In-Reply-To: <202310181626.C5BE0C21F@keescook>
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On 10/18/2023 4:35 PM, Kees Cook wrote:
> On Fri, Oct 13, 2023 at 05:58:03PM -0700, Jeff Johnson wrote:
>>> Let's also mark ath10k_vif.u.ap.ssid as __nonstring.
>>
>> what criteria is used to determine whether or not to use __nonstring?
>> doesn't the use of u8 vs char already communicate that distinction?
>> just want to know what other u8 arrays might require this.
>> FWIW the documentation referenced by the __nonstring macro explicitly refers
>> to "type array of char, signed char, or unsigned char"
> 
> The use of __nonstring is for byte arrays that are _not_ expected to be
> %NUL terminated. Unfortunately "char" vs "u8" isn't distinguished by the
> compiler. All byte arrays are treated as C strings unless __nonstring is
> used.

So is the plan to annotate every single binary blob array in the kernel 
as __nonstring? I suspect those outnumber string arrays.