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authorJia Lina <jialina01@baidu.com>2018-10-26 16:36:20 +0800
committerDr. David Alan Gilbert <dgilbert@redhat.com>2018-10-31 09:38:59 +0000
commit3d63da16fbcd05405efd5946000cdb45474a9bad (patch)
treeeae180d6f698df45e85d62b99c1a41cc2f87bd2a /migration/savevm.c
parentea3b23e5ffc4b937958ba54b006a2a5e2e664f12 (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>
Diffstat (limited to 'migration/savevm.c')
-rw-r--r--migration/savevm.c19
1 files changed, 11 insertions, 8 deletions
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 {