Re: [PATCH v2 13/14] qga: Fix qmp_guest_get_memory_blocks() error handling

[Eric Blake <eblake@redhat.com>]

On 4/22/20 8:07 AM, Markus Armbruster wrote:
> The Error ** argument must be NULL, &error_abort, &error_fatal, or a
> pointer to a variable containing NULL.  Passing an argument of the
> latter kind twice without clearing it in between is wrong: if the
> first call sets an error, it no longer points to NULL for the second
> call.
> 
> qmp_guest_get_memory_blocks() passes &local_err to
> transfer_memory_block() in a loop.  If this fails in more than one
> iteration, it can trip error_setv()'s assertion.
> 
> Fix it to break the loop.
> 
> Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>   qga/commands-posix.c | 3 +++
>   1 file changed, 3 insertions(+)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index a52af0315f..ae1348dc8f 100644
> --- a/qga/commands-posix.c
> +++ b/qga/commands-posix.c
> @@ -2518,6 +2518,9 @@ GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
>           mem_blk->phys_index = strtoul(&de->d_name[6], NULL, 10);
>           mem_blk->has_can_offline = true; /* lolspeak ftw */
>           transfer_memory_block(mem_blk, true, NULL, &local_err);
> +        if (local_err) {
> +            break;
> +        }
>   
>           entry = g_malloc0(sizeof *entry);
>           entry->value = mem_blk;
> 

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