On Tue, Oct 15, 2024 at 07:04:37PM +0200, Hanna Czenczek wrote: > migration/savevm.c contains some calls to vmstate_save() that are > followed by migrate_set_error() if the integer return value indicates an > error. migrate_set_error() requires that the `Error *` object passed to > it is set. Therefore, vmstate_save() is assumed to always set *errp on > error. > > Right now, that assumption is not met: vmstate_save_state_v() (called > internally by vmstate_save()) will not set *errp if > vmstate_subsection_save() or vmsd->post_save() fail. Fix that by adding > an *errp parameter to vmstate_subsection_save(), and by generating a > generic error in case post_save() fails (as is already done for > pre_save()). > > Without this patch, qemu will crash after vmstate_subsection_save() or > post_save() have failed inside of a vmstate_save() call (unless > migrate_set_error() then happen to discard the new error because > s->error is already set). This happens e.g. when receiving the state > from a virtio-fs back-end (virtiofsd) fails. > > Signed-off-by: Hanna Czenczek <hre...@redhat.com> > --- > v2: As suggested by Peter, after vmsd->post_save(), change the condition > from `if (!ret)` to `if (!ret && ps_ret)` so we will not create an > error object in case of success (that would then be leaked, most > likely). > --- > migration/vmstate.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-)
queued, thanks! -- Peter Xu
