Re: [PATCH v4 05/14] of: Fix available buffer size calculating error in API of_device_uevent_modalias()

[Rob Herring]

On Thu, Jan 09, 2025 at 09:26:56PM +0800, Zijun Hu wrote:
> From: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
> 
> of_device_uevent_modalias() saves MODALIAS value from offset
> (@env->buflen - 1), so the available buffer size should be
> (sizeof(@env->buf) - @env->buflen + 1), but it uses the wrong
> size (sizeof(@env->buf) - @env->buflen).
> 
> Fix by using size of space from char '\0' inclusive which ends "MODALIAS=".

I prefer to get the printf specifier change merged rather than reviewing 
if this is correct and doesn't introduce any new bugs. We're under 
utilizing the buffer by 1 byte. I doubt anyone will ever hit that and 
it's not any worse than if they exceed the correct size of the buffer.

> 
> Fixes: dd27dcda37f0 ("of/device: merge of_device_uevent")
> Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
> ---
>  drivers/of/device.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)