Re: [PATCH v1] migration: Use QAPI_CLONE_MEMBERS in migrate_params_test_apply

[Peter Xu <peterx@redhat.com>]

On Tue, Apr 14, 2026 at 07:37:18PM -0300, Fabiano Rosas wrote:
> Use QAPI_CLONE_MEMBERS instead of making an assignment. The QAPI
> method makes the handling of the TLS strings more intuitive because it
> clones them as well.
> 
> This also fixes a segfault when a NULL TLS option is accessed as part
> of a validation check for another option (e.g. in the zero-copy +
> multifd compression case). Details follow:
> 
> Currently, after copying s->parameters to the temporary
> MigrationParameters object before migrate_params_check(), the
> references in temporary object to the TLS options are dropped, either
> because:
> 
> a) the user set a new option, in which case that's fine as
>    s->parameters still holds the reference to the old memory or,
> 
> b) the user did not set a new option, in which case keeping the
>    references in the temporary object would later cause them to be
>    freed along with it, leading to double-free when s->parameters is
>    also freed later on.
> 
> In this second case, it was overlooked that the TLS options can be
> accessed already during migrate_params_check() as part of validation
> of another option. Those pointers should not have been cleared.
> 
> Using QAPI_CLONE_MEMBERS fixes the issue because the temporary object
> is not stealing a reference from s->parameters anymore.
> 
> Fixes: aed97f0563 ("migration: Normalize tls arguments")
> Reported-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
> Link: https://lore.kernel.org/r/a65a1049-9f19-460a-8e27-a62bb30d2727@maciej.szmigiero.name
> Reviewed-by: Peter Xu <peterx@redhat.com>
> Signed-off-by: Fabiano Rosas <farosas@suse.de>

Queued and added cc:stable.

-- 
Peter Xu