Re: [PATCH] tipc: fix -Wstringop-truncation warnings

[Ying Xue]

On 11/12/20 5:34 PM, Kang Wenlin wrote:
> From: Wenlin Kang <wenlin.kang@xxxxxxxxxxxxx>
> 
> Replace strncpy() with strscpy(), fixes the following warning:
> 
> In function 'bearer_name_validate',
>     inlined from 'tipc_enable_bearer' at net/tipc/bearer.c:246:7:
> net/tipc/bearer.c:141:2: warning: 'strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
>   strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
>   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Signed-off-by: Wenlin Kang <wenlin.kang@xxxxxxxxxxxxx>

Acked-by: Ying Xue <ying.xue@xxxxxxxxxxxxx>

> ---
>  net/tipc/bearer.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
> index 650414110452..2241d5a38f7b 100644
> --- a/net/tipc/bearer.c
> +++ b/net/tipc/bearer.c
> @@ -139,10 +139,7 @@ static int bearer_name_validate(const char *name,
>  	u32 if_len;
>  
>  	/* copy bearer name & ensure length is OK */
> -	name_copy[TIPC_MAX_BEARER_NAME - 1] = 0;
> -	/* need above in case non-Posix strncpy() doesn't pad with nulls */
> -	strncpy(name_copy, name, TIPC_MAX_BEARER_NAME);
> -	if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0)
> +	if (strscpy(name_copy, name, TIPC_MAX_BEARER_NAME) < 0)
>  		return 0;
>  
>  	/* ensure all component parts of bearer name are present */
>