[PATCH QEMU HCI-8.1 v4 06/31] migration: Plug memory leaks after migrate_set_error()

[Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>]

From: Markus Armbruster <armbru@redhat.com>

migrate_set_error(s, err) stores a copy of @err in @s.  The original
@err is not freed.  Most callers free it immediately.  Some callers
free it later, or pass it on.  And some leak it.  Fix those.

Perhaps migrate_set_error(s, err) should take ownership of @err.  The
callers that free it immediately would become simpler, and avoid a
copy and a deallocation.  The others would have to pass
error_copy(err).

andrey.drobyshev:
    This commit is cherry-picked as-is, with no modifications, from the
    upstream commit 93817ec39656.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Link: https://lore.kernel.org/r/20251115083500.2753895-2-armbru@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 migration/cpr-exec.c | 3 ++-
 migration/multifd.c  | 2 ++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/migration/cpr-exec.c b/migration/cpr-exec.c
index c4bdf2cb99f..d37293baec5 100644
--- a/migration/cpr-exec.c
+++ b/migration/cpr-exec.c
@@ -231,11 +231,12 @@ static void cpr_exec_cb(void *opaque)
     error_report_err(error_copy(err));
     migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED);
     migrate_set_error(s, err);
+    error_free(err);
+    err = NULL;
 
     /* Note, we can go from state COMPLETED to FAILED */
     migration_call_notifiers(MIG_EVENT_PRECOPY_FAILED, NULL);
 
-    err = NULL;
     if (!migration_block_activate(&err)) {
         /* error was already reported */
         error_free(err);
diff --git a/migration/multifd.c b/migration/multifd.c
index 5a723ae25d2..e369421b3ff 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -966,6 +966,7 @@ bool multifd_send_setup(void)
 
         if (!multifd_new_send_channel_create(p, &local_err)) {
             migrate_set_error(s, local_err);
+            error_free(local_err);
             ret = -1;
         }
     }
@@ -990,6 +991,7 @@ bool multifd_send_setup(void)
         ret = multifd_send_state->ops->send_setup(p, &local_err);
         if (ret) {
             migrate_set_error(s, local_err);
+            error_free(local_err);
             goto err;
         }
         assert(p->iov);

-- 
2.47.1