linux-kernel - Re: [PATCH] cpufreq: sun50i: Fix build warning around snprint()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAGRGNgWHkVkOP13jh-w1KQYeR_yeq1JgOt9a+R40F8DGYKMtkg@mail.gmail.com>
Date: Tue, 23 Apr 2024 11:38:24 +1000
From: Julian Calaby <julian.calaby@...il.com>
To: Viresh Kumar <viresh.kumar@...aro.org>
Cc: "Rafael J. Wysocki" <rafael@...nel.org>, Yangtao Li <tiny.windzz@...il.com>, 
	Chen-Yu Tsai <wens@...e.org>, Jernej Skrabec <jernej.skrabec@...il.com>, 
	Samuel Holland <samuel@...lland.org>, linux-pm@...r.kernel.org, 
	Vincent Guittot <vincent.guittot@...aro.org>, kernel test robot <lkp@...el.com>, 
	linux-arm-kernel@...ts.infradead.org, linux-sunxi@...ts.linux.dev, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] cpufreq: sun50i: Fix build warning around snprint()

Hi Viresh,

On Mon, Apr 22, 2024 at 1:31 PM Viresh Kumar <viresh.kumar@...aro.org> wrote:
>
> The Sun50i driver generates a warning with W=1:
>
> warning: '%d' directive output may be truncated writing between 1 and 10 bytes into a region of size 2 [-Wformat-truncation=]
>
> Fix it by allocating a big enough array to print an integer.
>
> Reported-by: kernel test robot <lkp@...el.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202404191715.LDwMm2gP-lkp@intel.com/
> Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>

This'll absolutely fix the issue here, so:

Reviewed-by: Julian Calaby <julian.calaby@...il.com>

However:

> ---
>  drivers/cpufreq/sun50i-cpufreq-nvmem.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/cpufreq/sun50i-cpufreq-nvmem.c b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> index 30e5c337611c..cd50cea16a87 100644
> --- a/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> +++ b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> @@ -208,7 +206,7 @@ static int sun50i_cpufreq_get_efuse(void)
>  static int sun50i_cpufreq_nvmem_probe(struct platform_device *pdev)
>  {
>         int *opp_tokens;
> -       char name[MAX_NAME_LEN];
> +       char name[] = "speedXXXXXXXXXXX"; /* Integers can take 11 chars max */

Would it make sense to just set a static length for the string here,
say 17-20 characters and add a comment explaining the number, say: /*
"speed" + 11 chars for the int */

The string constant, while it'll probably be optimised away, seems
weird and wasteful.

Thanks,

-- 
Julian Calaby

Email: julian.calaby@...il.com
Profile: http://www.google.com/profiles/julian.calaby/