Subject: Re: [PATCH] drivers/net/wireless/iwlegacy: adding check length for parameter buf

From: Chen Gang F T <[email-masked]>
Date: Sun, 20 Jan 2013 18:43:48 +0800

oh, sorry, it is my fault.

  according to fill_write_buffer in fs/sysfs/file.c,
    we can assume that 'const char *buf' must be '\0' based string.

  please skip this patch.

gchen.

于 2013年01月20日 17:53, Chen Gang 写道:
> 
>   the parameter 'const char *buf' may be not '\0' based string.
>   so need check the length before use it.
> 
> additinal info:
>   originally, it had the relative checking.
>   but it was deleted when fix another issues (using strlcpy instead of
> strncpy)
>   and now, we need restore the checking (but still keep strlcpy)
> 
> Signed-off-by: Chen Gang <[email-masked]>
> ---
>  drivers/net/wireless/iwlegacy/3945-mac.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/iwlegacy/3945-mac.c
> b/drivers/net/wireless/iwlegacy/3945-mac.c
> index 050ce7c..71cdbac 100644
> --- a/drivers/net/wireless/iwlegacy/3945-mac.c
> +++ b/drivers/net/wireless/iwlegacy/3945-mac.c
> @@ -3273,7 +3273,7 @@ il3945_store_measurement(struct device *d, struct
> device_attribute *attr,
> 
>  	if (count) {
>  		char *p = buffer;
> -		strlcpy(buffer, buf, sizeof(buffer));
> +		strlcpy(buffer, buf, min(sizeof(buffer), count));
>  		channel = simple_strtoul(p, NULL, 0);
>  		if (channel)
>  			params.channel = channel;
> 

-- 
Chen Gang

Flying Transformer