[PATCH 0/5] spi: replace strcpy(), sprintf() and simple_strtoul() with strscpy(), snprintf() and kstrtoul()

[PATCH 0/5] spi: replace strcpy(), sprintf() and simple_strtoul() with strscpy(), snprintf() and kstrtoul()

[Aayush Kumar]

Replace strcpy(), sprintf() and simple_strtoul() with their safer
modern equivalents (strscpy, snprintf, kstrtoul).

Aayush Kumar (5):
  spi: butterfly: Use strscpy() instead of strcpy()
  spi: lm70llp: Use strscpy() instead of strcpy()
  spi: tle62x0: Use kstrtoul() instead of simple_strtoul()
  spi: omap2-mcspi: Use snprintf() instead of sprintf()
  spi: s3c64xx: Use snprintf() instead of sprintf()

 drivers/spi/spi-butterfly.c   | 3 ++-
 drivers/spi/spi-lm70llp.c     | 2 +-
 drivers/spi/spi-omap2-mcspi.c | 6 ++++--
 drivers/spi/spi-s3c64xx.c     | 3 ++-
 drivers/spi/spi-tle62x0.c     | 6 +++---
 5 files changed, 12 insertions(+), 8 deletions(-)

-- 
2.56.0

[PATCH 1/5] spi: butterfly: Use strscpy() instead of strcpy()

[Aayush Kumar]

Use a safer function strscpy() instead of strcpy() for copying to
arrays. Only idiomatic code replacement, and no functional changes.

Signed-off-by: Aayush Kumar <code@aayushk.dev>
---
 drivers/spi/spi-butterfly.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-butterfly.c b/drivers/spi/spi-butterfly.c
index 84eb454ed..5e1e205bb 100644
--- a/drivers/spi/spi-butterfly.c
+++ b/drivers/spi/spi-butterfly.c
@@ -259,7 +259,8 @@ static void butterfly_attach(struct parport *p)
 	 */
 
 	pp->info[0].max_speed_hz = 15 * 1000 * 1000;
-	strcpy(pp->info[0].modalias, "mtd_dataflash");
+	strscpy(pp->info[0].modalias, "mtd_dataflash",
+		sizeof(pp->info[0].modalias));
 	pp->info[0].platform_data = &flash;
 	pp->info[0].chip_select = 1;
 	pp->info[0].controller_data = pp;
-- 
2.56.0

[PATCH 2/5] spi: lm70llp: Use strscpy() instead of strcpy()

[Aayush Kumar]

Use a safer function strscpy() instead of strcpy() for copying to
arrays. Only idiomatic code replacement, and no functional changes.

Signed-off-by: Aayush Kumar <code@aayushk.dev>
---
 drivers/spi/spi-lm70llp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-lm70llp.c b/drivers/spi/spi-lm70llp.c
index e61e89b41..bd8028892 100644
--- a/drivers/spi/spi-lm70llp.c
+++ b/drivers/spi/spi-lm70llp.c
@@ -252,7 +252,7 @@ static void spi_lm70llp_attach(struct parport *p)
 	 * We are binding to the generic drivers/hwmon/lm70.c device
 	 * driver.
 	 */
-	strcpy(pp->info.modalias, "lm70");
+	strscpy(pp->info.modalias, "lm70", sizeof(pp->info.modalias));
 	pp->info.max_speed_hz = 6 * 1000 * 1000;
 	pp->info.chip_select = 0;
 	pp->info.mode = SPI_3WIRE | SPI_MODE_0;
-- 
2.56.0

[PATCH 3/5] spi: tle62x0: Use kstrtoul() instead of simple_strtoul()

[Aayush Kumar]

Use the recommended kstrtoul() instead of the deprecated
simple_strtoul(). Check the return value and reject invalid values.

Signed-off-by: Aayush Kumar <code@aayushk.dev>
---
 drivers/spi/spi-tle62x0.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-tle62x0.c b/drivers/spi/spi-tle62x0.c
index dd8bfb3f3..986d78ab4 100644
--- a/drivers/spi/spi-tle62x0.c
+++ b/drivers/spi/spi-tle62x0.c
@@ -151,10 +151,10 @@ static ssize_t tle62x0_gpio_store(struct device *dev,
 	struct tle62x0_state *st = dev_get_drvdata(dev);
 	int gpio_num = to_gpio_num(attr);
 	unsigned long val;
-	char *endp;
+	int ret;
 
-	val = simple_strtoul(buf, &endp, 0);
-	if (buf == endp)
+	ret = kstrtoul(buf, 0, &val);
+	if (ret)
 		return -EINVAL;
 
 	dev_dbg(dev, "setting gpio %d to %ld\n", gpio_num, val);
-- 
2.56.0

[PATCH 4/5] spi: omap2-mcspi: Use snprintf() instead of sprintf()

[Aayush Kumar]

Use snprintf() instead of sprintf() to avoid potential buffer
overflows when formatting DMA channel names.

Signed-off-by: Aayush Kumar <code@aayushk.dev>
---
 drivers/spi/spi-omap2-mcspi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index a3355147f..311ee0ca9 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -1544,8 +1544,10 @@ static int omap2_mcspi_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	for (i = 0; i < ctlr->num_chipselect; i++) {
-		sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i);
-		sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
+		snprintf(mcspi->dma_channels[i].dma_rx_ch_name,
+			 sizeof(mcspi->dma_channels[i].dma_rx_ch_name), "rx%d", i);
+		snprintf(mcspi->dma_channels[i].dma_tx_ch_name,
+			 sizeof(mcspi->dma_channels[i].dma_tx_ch_name), "tx%d", i);
 
 		status = omap2_mcspi_request_dma(mcspi,
 						 &mcspi->dma_channels[i]);
-- 
2.56.0

[PATCH 5/5] spi: s3c64xx: Use snprintf() instead of sprintf()

[Aayush Kumar]

Use snprintf() instead of sprintf() to avoid potential buffer
overflows when formatting the clock name.

Signed-off-by: Aayush Kumar <code@aayushk.dev>
---
 drivers/spi/spi-s3c64xx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 8d4120cf9..8195bf376 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1331,7 +1331,8 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, PTR_ERR(sdd->clk),
 				     "Unable to acquire clock 'spi'\n");
 
-	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
+	snprintf(clk_name, sizeof(clk_name), "spi_busclk%d",
+		 sci->src_clk_nr);
 	sdd->src_clk = devm_clk_get_enabled(&pdev->dev, clk_name);
 	if (IS_ERR(sdd->src_clk))
 		return dev_err_probe(&pdev->dev, PTR_ERR(sdd->src_clk),
-- 
2.56.0

Re: [PATCH 2/5] spi: lm70llp: Use strscpy() instead of strcpy()

[David Laight]

On Fri,  9 Oct 2026 19:06:06 +0530
Aayush Kumar <code@aayushk.dev> wrote:

> Use a safer function strscpy() instead of strcpy() for copying to
> arrays. Only idiomatic code replacement, and no functional changes.
> 
> Signed-off-by: Aayush Kumar <code@aayushk.dev>
> ---
>  drivers/spi/spi-lm70llp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-lm70llp.c b/drivers/spi/spi-lm70llp.c
> index e61e89b41..bd8028892 100644
> --- a/drivers/spi/spi-lm70llp.c
> +++ b/drivers/spi/spi-lm70llp.c
> @@ -252,7 +252,7 @@ static void spi_lm70llp_attach(struct parport *p)
>  	 * We are binding to the generic drivers/hwmon/lm70.c device
>  	 * driver.
>  	 */
> -	strcpy(pp->info.modalias, "lm70");
> +	strscpy(pp->info.modalias, "lm70", sizeof(pp->info.modalias));

Come on, if you are going to do that use the two argument form.
Or just don't bother at all.
Do the test compiles - if the literal string is too long you'll
get a compile error for strcpy(), but strscpy() truncates and returns
an error.
So strcpy() is arguably better.

David

>  	pp->info.max_speed_hz = 6 * 1000 * 1000;
>  	pp->info.chip_select = 0;
>  	pp->info.mode = SPI_3WIRE | SPI_MODE_0;

Re: [PATCH 2/5] spi: lm70llp: Use strscpy() instead of strcpy()

[Aayush Kumar]

On Fri, Oct 9, 2026 at 7:58 PM David Laight
<david.laight.linux@gmail.com> wrote:
> So strcpy() is arguably better.

Fair point, I'll drop both the strscpy patches in v2. Thanks