Re: [Cluster-devel] [PATCH] gfs2: move from strlcpy with unused retval to strscpy

[Andrew Price <anprice@redhat.com>]

On 18/08/2022 22:01, Wolfram Sang wrote:
> Follow the advice of the below link and prefer 'strscpy' in this
> subsystem. Conversion is 1:1 because the return value is not used.
> Generated by a coccinelle script.
> 
> Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>   fs/gfs2/ops_fstype.c | 10 +++++-----
>   1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
> index 549879929c84..b57d9bf4b123 100644
> --- a/fs/gfs2/ops_fstype.c
> +++ b/fs/gfs2/ops_fstype.c
> @@ -381,8 +381,8 @@ static int init_names(struct gfs2_sbd *sdp, int silent)
>   	if (!table[0])
>   		table = sdp->sd_vfs->s_id;
>   
> -	strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
> -	strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
> +	strscpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
> +	strscpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);

Perhaps the size should be changed to GFS2_LOCKNAME_LEN to match the 
size of the destination, too.

With that addition, this patch fixes this syzkaller report:

https://listman.redhat.com/archives/cluster-devel/2022-August/022755.html

Andy

>   
>   	table = sdp->sd_table_name;
>   	while ((table = strchr(table, '/')))
> @@ -1439,13 +1439,13 @@ static int gfs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
>   
>   	switch (o) {
>   	case Opt_lockproto:
> -		strlcpy(args->ar_lockproto, param->string, GFS2_LOCKNAME_LEN);
> +		strscpy(args->ar_lockproto, param->string, GFS2_LOCKNAME_LEN);
>   		break;
>   	case Opt_locktable:
> -		strlcpy(args->ar_locktable, param->string, GFS2_LOCKNAME_LEN);
> +		strscpy(args->ar_locktable, param->string, GFS2_LOCKNAME_LEN);
>   		break;
>   	case Opt_hostdata:
> -		strlcpy(args->ar_hostdata, param->string, GFS2_LOCKNAME_LEN);
> +		strscpy(args->ar_hostdata, param->string, GFS2_LOCKNAME_LEN);
>   		break;
>   	case Opt_spectator:
>   		args->ar_spectator = 1;