diff options
| author | Fabiano Rosas <farosas@suse.de> | 2024-01-19 20:39:18 -0300 |
|---|---|---|
| committer | Peter Xu <peterx@redhat.com> | 2024-01-29 11:02:12 +0800 |
| commit | 27eb8499edb2bc952c29ddae0bdac9fc959bf7b1 (patch) | |
| tree | a82c4f9d7959ed2d37b0f0bd320a92c2a8093ef5 /migration | |
| parent | 0a5d1108aba6308752a82201a441f957e5937211 (diff) | |
| download | qemu-27eb8499edb2bc952c29ddae0bdac9fc959bf7b1.zip qemu-27eb8499edb2bc952c29ddae0bdac9fc959bf7b1.tar.gz qemu-27eb8499edb2bc952c29ddae0bdac9fc959bf7b1.tar.bz2 | |
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>
Diffstat (limited to 'migration')
| -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 219447d..cf17b68 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -648,6 +648,7 @@ 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 @@ -713,6 +714,7 @@ 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: |