[Ocfs2-devel] [patch] ocfs2: tighten up strlen() checking

[Sunil Mushran]

Acked-by: Sunil Mushran <sunil.mushran at oracle.com>

On 07/10/2010 07:33 AM, Dan Carpenter wrote:
> This function is only called from one place and it's like this:
> 	dlm_register_domain(conn->cc_name, dlm_key,&fs_version);
>
> The "conn->cc_name" is 64 characters long.  If strlen(conn->cc_name)
> were equal to O2NM_MAX_NAME_LEN (64) that would be a bug because
> strlen() doesn't count the NULL character.
>
> In fact, if you look how O2NM_MAX_NAME_LEN is used, it mostly describes
> 64 character buffers.  The only exception is nd_name from struct
> o2nm_node.
>
> Anyway I looked into it and in this case the domain string comes from
> osb->uuid_str in ocfs2_setup_osb_uuid().  That's 32 characters and NULL
> which easily fits into O2NM_MAX_NAME_LEN.  This patch doesn't change how
> the code works, but I think it makes the code a little cleaner.
>
> Signed-off-by: Dan Carpenter<error27 at gmail.com>
> ---
> Or we could get rid of check entirely.
>
> diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
> index 6b5a492..084b051 100644
> --- a/fs/ocfs2/dlm/dlmdomain.c
> +++ b/fs/ocfs2/dlm/dlmdomain.c
> @@ -1671,7 +1671,7 @@ struct dlm_ctxt * dlm_register_domain(const char *domain,
>   	struct dlm_ctxt *dlm = NULL;
>   	struct dlm_ctxt *new_ctxt = NULL;
>
> -	if (strlen(domain)>  O2NM_MAX_NAME_LEN) {
> +	if (strlen(domain)>= O2NM_MAX_NAME_LEN) {
>   		ret = -ENAMETOOLONG;
>   		mlog(ML_ERROR, "domain name length too long\n");
>   		goto leave;
>