Subject: Re: [PATCH net] mctp i2c: handle NULL header address

From: Simon Horman <[email-masked]>
Date: Fri, 18 Oct 2024 21:06:06 +0100

On Fri, Oct 18, 2024 at 11:07:56AM +0800, Matt Johnston via B4 Relay wrote:
> From: Matt Johnston <[email-masked]>
> 
> daddr can be NULL if there is no neighbour table entry present,
> in that case the tx packet should be dropped.

Hi Matt,

Is there also a situation where saddr can be null?
The patch adds that check but it isn't mentioned here.

> 
> Fixes: f5b8abf9fc3d ("mctp i2c: MCTP I2C binding driver")
> Cc: [email-masked]
> Reported-by: Dung Cao <[email-masked]>
> Signed-off-by: Matt Johnston <[email-masked]>
> ---
>  drivers/net/mctp/mctp-i2c.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git drivers/net/mctp/mctp-i2c.c drivers/net/mctp/mctp-i2c.c
> index 4dc057c121f5..e70fb6687994 100644
> --- drivers/net/mctp/mctp-i2c.c
> +++ drivers/net/mctp/mctp-i2c.c

Unfortunately tooling expects an extra level of the directory hierarchy,
something like the following. And is unable to apply this patch in
it's current form.

diff --git a/drivers/net/mctp/mctp-i2c.c b/drivers/net/mctp/mctp-i2c.c
index 4dc057c121f5..e70fb6687994 100644
--- a/drivers/net/mctp/mctp-i2c.c
+++ b/drivers/net/mctp/mctp-i2c.c

> @@ -588,6 +588,9 @@ static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev,
>  	if (len > MCTP_I2C_MAXMTU)
>  		return -EMSGSIZE;
>  
> +	if (!daddr || !saddr)
> +		return -EINVAL;
> +
>  	lldst = *((u8 *)daddr);
>  	llsrc = *((u8 *)saddr);
>  
> 
> ---

-- 
pw-bot: changes-requested