Re: [PATCH v4 net-next: rds] replace strncpy with strscpy_pad

[Allison Henderson <allison.henderson@oracle.com>]

On Mon, 2025-05-19 at 15:51 +0300, Baris Can Goral wrote:
> The strncpy() function is actively dangerous to use since it may not
> NULL-terminate the destination string, resulting in potential memory.
It looks like we lost the last part of this phrase? I think you meant to quote the link: "...potential memory content
exposures, unbounded reads, or crashes."

Other than that I think it looks ok.  Thanks!
Allison

> Link: https://urldefense.com/v3/__https://github.com/KSPP/linux/issues/90__;!!ACWV5N9M2RV99hQ!Ja5aVj9u5vDpeBsiMWIGFvGhVzCbcj-gUOS9qIbQ_QDVAy_GU9E4yl_yCjzYJ61uEfuo368zv8bY5vsmB9yxR-7h$ 
> 
> In addition, strscpy_pad is more appropriate because it also zero-fills
> any remaining space in the destination if the source is shorter than
> the provided buffer size.
> 
> Signed-off-by: Baris Can Goral <goralbaris@gmail.com>
> ---
>  net/rds/connection.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/net/rds/connection.c b/net/rds/connection.c
> index c749c5525b40..d62f486ab29f 100644
> --- a/net/rds/connection.c
> +++ b/net/rds/connection.c
> @@ -749,8 +749,7 @@ static int rds_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
>  	cinfo->laddr = conn->c_laddr.s6_addr32[3];
>  	cinfo->faddr = conn->c_faddr.s6_addr32[3];
>  	cinfo->tos = conn->c_tos;
> -	strncpy(cinfo->transport, conn->c_trans->t_name,
> -		sizeof(cinfo->transport));
> +	strscpy_pad(cinfo->transport, conn->c_trans->t_name);
>  	cinfo->flags = 0;
>  
>  	rds_conn_info_set(cinfo->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),
> @@ -775,8 +774,7 @@ static int rds6_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
>  	cinfo6->next_rx_seq = cp->cp_next_rx_seq;
>  	cinfo6->laddr = conn->c_laddr;
>  	cinfo6->faddr = conn->c_faddr;
> -	strncpy(cinfo6->transport, conn->c_trans->t_name,
> -		sizeof(cinfo6->transport));
> +	strscpy_pad(cinfo6->transport, conn->c_trans->t_name);
>  	cinfo6->flags = 0;
>  
>  	rds_conn_info_set(cinfo6->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),