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

[PATCH] drm/rockchip: 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/rockchip/inno_hdmi.c   |    2 +-
 drivers/gpu/drm/rockchip/rk3066_hdmi.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/inno_hdmi.c b/drivers/gpu/drm/rockchip/inno_hdmi.c
index f51774866f41..9afb889963c1 100644
--- a/drivers/gpu/drm/rockchip/inno_hdmi.c
+++ b/drivers/gpu/drm/rockchip/inno_hdmi.c
@@ -797,7 +797,7 @@ static struct i2c_adapter *inno_hdmi_i2c_adapter(struct inno_hdmi *hdmi)
 	adap->dev.parent = hdmi->dev;
 	adap->dev.of_node = hdmi->dev->of_node;
 	adap->algo = &inno_hdmi_algorithm;
-	strlcpy(adap->name, "Inno HDMI", sizeof(adap->name));
+	strscpy(adap->name, "Inno HDMI", sizeof(adap->name));
 	i2c_set_adapdata(adap, hdmi);
 
 	ret = i2c_add_adapter(adap);
diff --git a/drivers/gpu/drm/rockchip/rk3066_hdmi.c b/drivers/gpu/drm/rockchip/rk3066_hdmi.c
index 90145ad96984..b5d042ee052f 100644
--- a/drivers/gpu/drm/rockchip/rk3066_hdmi.c
+++ b/drivers/gpu/drm/rockchip/rk3066_hdmi.c
@@ -730,7 +730,7 @@ static struct i2c_adapter *rk3066_hdmi_i2c_adapter(struct rk3066_hdmi *hdmi)
 	adap->dev.parent = hdmi->dev;
 	adap->dev.of_node = hdmi->dev->of_node;
 	adap->algo = &rk3066_hdmi_algorithm;
-	strlcpy(adap->name, "RK3066 HDMI", sizeof(adap->name));
+	strscpy(adap->name, "RK3066 HDMI", sizeof(adap->name));
 	i2c_set_adapdata(adap, hdmi);
 
 	ret = i2c_add_adapter(adap);

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

[Kees Cook]

On Mon, May 22, 2023 at 03:51:49PM +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/rockchip: Replace all non-returning strlcpy with strscpy

[Kees Cook]

On Mon, 22 May 2023 15:51:49 +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/rockchip: Replace all non-returning strlcpy with strscpy
      https://git.kernel.org/kees/c/3bc490653e12

-- 
Kees Cook