[pve-devel] [RFC v2 pve-cluster 1/4] prefer 'name' subkey over 'ring0_addr' for nodename

[Wolfgang Bumiller]

On Wed, Oct 07, 2015 at 01:34:57PM +0200, Thomas Lamprecht wrote:
> @@ -97,6 +97,13 @@ cmap_read_clusternodes(
>  				cfs_critical("cmap_get %s failed %d", key_name, result);
>  			}
>  		} else if (strcmp(subkey, "ring0_addr") == 0) {
> +			// prefer the 'name' subkey over 'ring0_addr', allows ring0_addr
> +			// to be IP addresses without changing the nodename
> +			if (name == NULL &&
> +			    (result = cmap_get_string(handle, key_name, &name)) != CS_OK) {
> +				cfs_critical("cmap_get %s failed %d", key_name, result);
> +			}
> +		} else if (strcmp(subkey, "name") == 0) {

If `ring0_addr` is read before `name` then `cmap_get_string` would
replace `name` without freeing it first - leaking - since `name` is only
freed in the `id != last_id` case and after the loop. (Unless cmap is
sorted, which I doubt, but if it is then this should be commented).
cmap_get_string() only assigns and doesn't care what the pointer
contained before.

>  			if ((result = cmap_get_string(handle, key_name, &name)) != CS_OK) {
>  				cfs_critical("cmap_get %s failed %d", key_name, result);
>  			}
> --