Re: [PATCH] smack:beyond ARRAY_SIZE of data

[Casey Schaufler]

Roel Kluin wrote:
> Do not go beyond ARRAY_SIZE of data
>
> Signed-off-by: Roel Kluin <roel.kluin@xxxxxxxxx>
>   

Acked-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>

Thank you. The fix is appreciated.


> ---
>   
>>> -	if (count < SMK_NETLBLADDRMIN || count > SMK_NETLBLADDRMAX)
>>> +	if (count < SMK_NETLBLADDRMIN || count >= SMK_NETLBLADDRMAX)
>>>   
>>>       
>> There is a problem here, but this won't fix it. The buffer needs to be
>> allocated bigger than the potential contents (should be
>> SMK_NETLBLADDRMAX + 1 instead of SMK_NETLBLADDRMAX. Your patch will clip
>> the last byte off of a maximum length specification.
>>     
>
> Ok, how about this?
>
> diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
> index e03a7e1..10a4604 100644
> --- a/security/smack/smackfs.c
> +++ b/security/smack/smackfs.c
> @@ -775,7 +775,7 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
>  	struct sockaddr_in newname;
>  	char smack[SMK_LABELLEN];
>  	char *sp;
> -	char data[SMK_NETLBLADDRMAX];
> +	char data[SMK_NETLBLADDRMAX + 1];
>  	char *host = (char *)&newname.sin_addr.s_addr;
>  	int rc;
>  	struct netlbl_audit audit_info;
>
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