Re: [PATCH v3 1/4] nbd/server: Prefer heap over stack for parsing client names

[Eric Blake]

On 11/13/19 8:46 PM, Eric Blake wrote:
> As long as we limit NBD names to 256 bytes (the bare minimum permitted
> by the standard), stack-allocation works for parsing a name received
> from the client.  But as mentioned in a comment, we eventually want to
> permit up to the 4k maximum of the NBD standard, which is too large
> for stack allocation; so switch everything in the server to use heap
> allocation.  For now, there is no change in actually supported name
> length.
>
> Signed-off-by: Eric Blake <address@hidden>
> ---
>   include/block/nbd.h | 10 +++++-----
>   nbd/server.c        | 25 +++++++++++++++----------
>   2 files changed, 20 insertions(+), 15 deletions(-)

> @@ -427,7 +431,7 @@ static void nbd_check_meta_export(NBDClient *client)
>   static int nbd_negotiate_handle_export_name(NBDClient *client, bool no_zeroes,
>                                               Error **errp)
>   {
> -    char name[NBD_MAX_NAME_SIZE + 1];
> +    g_autofree char *name;

This needs to be:

g_autofree char *name = NULL;

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org