[PATCH] drm/sun4i: hdmi: Replace all non-returning strlcpy with strscpy

[PATCH] drm/sun4i: hdmi: Replace all non-returning strlcpy with strscpy

[Azeem Shaikh]

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
 drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c
index c7d7e9fff91c..d1a65a921f5a 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c
@@ -304,7 +304,7 @@ int sun4i_hdmi_i2c_create(struct device *dev, struct sun4i_hdmi *hdmi)
 	adap->owner = THIS_MODULE;
 	adap->class = I2C_CLASS_DDC;
 	adap->algo = &sun4i_hdmi_i2c_algorithm;
-	strlcpy(adap->name, "sun4i_hdmi_i2c adapter", sizeof(adap->name));
+	strscpy(adap->name, "sun4i_hdmi_i2c adapter", sizeof(adap->name));
 	i2c_set_adapdata(adap, hdmi);
 
 	ret = i2c_add_adapter(adap);

Re: [PATCH] drm/sun4i: hdmi: Replace all non-returning strlcpy with strscpy

[Kees Cook]

On Mon, May 22, 2023 at 03:53:31PM +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
> 
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
> 
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

Re: [PATCH] drm/sun4i: hdmi: Replace all non-returning strlcpy with strscpy

[Kees Cook]

On Mon, 22 May 2023 15:53:31 +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
> 
> [...]

Applied to for-next/hardening, thanks!

[1/1] drm/sun4i: hdmi: Replace all non-returning strlcpy with strscpy
      https://git.kernel.org/kees/c/6036094a9380

-- 
Kees Cook