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x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231005_070235_682405_2B6C9AAF X-CRM114-Status: GOOD ( 35.22 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, 30 Sep 2023 10:57:03 -0700 Kees Cook wrote: > On Sat, Sep 30, 2023 at 06:41:18PM +0100, Jonathan Cameron wrote: > > On Sat, 23 Sep 2023 20:15:09 -0700 > > Kees Cook wrote: > > > > > On Thu, Sep 21, 2023 at 04:54:00AM +0000, Justin Stitt wrote: > > > > `strncpy` is deprecated for use on NUL-terminated destination strings [1]. > > > > > > > > We should prefer more robust and less ambiguous string interfaces. > > > > > > > > We expect adc->chan_name[val] to be NUL-terminated based on ch_name's > > > > use within functions that expect NUL-terminated strings like strncmp and > > > > printf-likes: > > > > | if (!strncmp(stm32_adc_ic[i].name, ch_name, STM32_ADC_CH_SZ)) { > > > > | /* Check internal channel availability */ > > > > | switch (i) { > > > > | case STM32_ADC_INT_CH_VDDCORE: > > > > | if (!adc->cfg->regs->or_vddcore.reg) > > > > | dev_warn(&indio_dev->dev, > > > > | "%s channel not available\n", ch_name); > > > > ... > > > > > > > > There is no evidence that NUL-padding is needed either. > > > > > > Agreed -- it's used as a C string everywhere I can see. > > > > > > > > > > > Considering the above, a suitable replacement is `strscpy` [2] due to > > > > the fact that it guarantees NUL-termination on the destination buffer > > > > without unnecessarily NUL-padding. If, for any reason, NUL-padding _is_ > > > > required we should go for `strscpy_pad`. > > > > > > > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > > > > Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] > > > > Link: https://github.com/KSPP/linux/issues/90 > > > > Cc: linux-hardening@vger.kernel.org > > > > Signed-off-by: Justin Stitt > > > > --- > > > > Note: build-tested > > > > --- > > > > drivers/iio/adc/stm32-adc.c | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c > > > > index f7613efb870d..9cdcf396d901 100644 > > > > --- a/drivers/iio/adc/stm32-adc.c > > > > +++ b/drivers/iio/adc/stm32-adc.c > > > > @@ -2209,7 +2209,7 @@ static int stm32_adc_generic_chan_init(struct iio_dev *indio_dev, > > > > ret = -EINVAL; > > > > goto err; > > > > } > > > > - strncpy(adc->chan_name[val], name, STM32_ADC_CH_SZ); > > > > + strscpy(adc->chan_name[val], name, STM32_ADC_CH_SZ); > > > > > > I still prefer sizeof($dst), but yes, these are the same: > > > > > > char chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ]; > > > > > > If this needs a v2, please improve the Subject, but it is technically > > > correct, so: > > > > Hi Kees, > > > > I can tweak the subject whilst applying. What did you have in mind > > as a better one? > > I would use "iio: adc: stm32-adc: Replace deprecated strncpy() with strscpy()" Makes sense. I also used the () approach to identify functions in the text of the patch description instead of `funcname` Applied with those tweaks to the togreg branch of iio.git but initially just pushed out as testing to let 0-day take a look at it. Thanks, Jonathan > > Thanks! > > -Kees > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel