diff options
| author | Jia Lina <jialina01@baidu.com> | 2018-10-26 16:36:20 +0800 |
|---|---|---|
| committer | Dr. David Alan Gilbert <dgilbert@redhat.com> | 2018-10-31 09:38:59 +0000 |
| commit | 3d63da16fbcd05405efd5946000cdb45474a9bad (patch) | |
| tree | eae180d6f698df45e85d62b99c1a41cc2f87bd2a | |
| parent | ea3b23e5ffc4b937958ba54b006a2a5e2e664f12 (diff) | |
migration: avoid segmentfault when take a snapshot of a VM which being migrated
During an active background migration, snapshot will trigger a
segmentfault. As snapshot clears the "current_migration" struct
and updates "to_dst_file" before it finds out that there is a
migration task, Migration accesses the null pointer in
"current_migration" struct and qemu crashes eventually.
Signed-off-by: Jia Lina <jialina01@baidu.com>
Signed-off-by: Chai Wen <chaiwen@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Message-Id: <20181026083620.10172-1-jialina01@baidu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
| -rw-r--r-- | migration/migration.c | 2 | ||||
| -rw-r--r-- | migration/migration.h | 2 | ||||
| -rw-r--r-- | migration/savevm.c | 19 |
3 files changed, 14 insertions, 9 deletions
diff --git a/migration/migration.c b/migration/migration.c index 8b36e7f184..b261c1e4ce 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -742,7 +742,7 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) * Return true if we're already in the middle of a migration * (i.e. any of the active or setup states) */ -static bool migration_is_setup_or_active(int state) +bool migration_is_setup_or_active(int state) { switch (state) { case MIGRATION_STATUS_ACTIVE: diff --git a/migration/migration.h b/migration/migration.h index f7813f8261..e413d4d8b6 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -241,6 +241,8 @@ void migrate_fd_error(MigrationState *s, const Error *error); void migrate_fd_connect(MigrationState *s, Error *error_in); +bool migration_is_setup_or_active(int state); + void migrate_init(MigrationState *s); bool migration_is_blocked(Error **errp); /* True if outgoing migration has entered postcopy phase */ diff --git a/migration/savevm.c b/migration/savevm.c index 9992af4db4..ef707b8c43 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1327,21 +1327,25 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp) MigrationState *ms = migrate_get_current(); MigrationStatus status; - migrate_init(ms); - - ms->to_dst_file = f; + if (migration_is_setup_or_active(ms->state) || + ms->state == MIGRATION_STATUS_CANCELLING || + ms->state == MIGRATION_STATUS_COLO) { + error_setg(errp, QERR_MIGRATION_ACTIVE); + return -EINVAL; + } if (migration_is_blocked(errp)) { - ret = -EINVAL; - goto done; + return -EINVAL; } if (migrate_use_block()) { error_setg(errp, "Block migration and snapshots are incompatible"); - ret = -EINVAL; - goto done; + return -EINVAL; } + migrate_init(ms); + ms->to_dst_file = f; + qemu_mutex_unlock_iothread(); qemu_savevm_state_header(f); qemu_savevm_state_setup(f); @@ -1363,7 +1367,6 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp) error_setg_errno(errp, -ret, "Error while writing VM state"); } -done: if (ret != 0) { status = MIGRATION_STATUS_FAILED; } else { |