diff options
| author | Fabiano Rosas <farosas@suse.de> | 2024-01-19 20:39:18 -0300 |
|---|---|---|
| committer | Michael Tokarev <mjt@tls.msk.ru> | 2024-01-29 23:06:53 +0300 |
| commit | 106aa13c5bbb10d1742d9f2be1ac73a4918f6a27 (patch) | |
| tree | ce90978330e5046d3c2a360e5b3389cff36810a7 | |
| parent | e589e5ade7e7dc1f14eacc1670646439e4c07284 (diff) | |
migration: Fix use-after-free of migration state object
We're currently allowing the process_incoming_migration_bh bottom-half
to run without holding a reference to the 'current_migration' object,
which leads to a segmentation fault if the BH is still live after
migration_shutdown() has dropped the last reference to
current_migration.
In my system the bug manifests as migrate_multifd() returning true
when it shouldn't and multifd_load_shutdown() calling
multifd_recv_terminate_threads() which crashes due to an uninitialized
multifd_recv_state.
Fix the issue by holding a reference to the object when scheduling the
BH and dropping it before returning from the BH. The same is already
done for the cleanup_bh at migrate_fd_cleanup_schedule().
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1969
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240119233922.32588-2-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>
(cherry picked from commit 27eb8499edb2bc952c29ddae0bdac9fc959bf7b1)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
| -rw-r--r-- | migration/migration.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/migration/migration.c b/migration/migration.c index 3ce04b2aaf..ee5e0ba97a 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -650,6 +650,7 @@ static void process_incoming_migration_bh(void *opaque) MIGRATION_STATUS_COMPLETED); qemu_bh_delete(mis->bh); migration_incoming_state_destroy(); + object_unref(OBJECT(migrate_get_current())); } static void coroutine_fn @@ -708,6 +709,7 @@ process_incoming_migration_co(void *opaque) } mis->bh = qemu_bh_new(process_incoming_migration_bh, mis); + object_ref(OBJECT(migrate_get_current())); qemu_bh_schedule(mis->bh); return; fail: |