2023-05-22 16:03:29

by Azeem Shaikh

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Subject: [PATCH] drm/bridge: dw-hdmi: Replace all non-returning strlcpy with strscpy

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 <[email protected]>
---
drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 603bb3c51027..9d6dcaf317a1 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -533,7 +533,7 @@ static struct i2c_adapter *dw_hdmi_i2c_adapter(struct dw_hdmi *hdmi)
adap->owner = THIS_MODULE;
adap->dev.parent = hdmi->dev;
adap->algo = &dw_hdmi_algorithm;
- strlcpy(adap->name, "DesignWare HDMI", sizeof(adap->name));
+ strscpy(adap->name, "DesignWare HDMI", sizeof(adap->name));
i2c_set_adapdata(adap, hdmi);

ret = i2c_add_adapter(adap);



2023-05-22 20:19:19

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH] drm/bridge: dw-hdmi: Replace all non-returning strlcpy with strscpy

On Mon, May 22, 2023 at 03:52:10PM +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 <[email protected]>

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook

2023-05-23 17:32:26

by Robert Foss

[permalink] [raw]
Subject: Re: [PATCH] drm/bridge: dw-hdmi: Replace all non-returning strlcpy with strscpy

From: Robert Foss <[email protected]>

On Mon, 22 May 2023 15:52:10 +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, thanks!

[1/1] drm/bridge: dw-hdmi: Replace all non-returning strlcpy with strscpy
https://cgit.freedesktop.org/drm/drm-misc/commit/?id=37cee4876a45



Rob