During an active background migraion, 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: jialina01 <[email protected]> Signed-off-by: chaiwen <[email protected]> Signed-off-by: zhangyu <[email protected]> --- migration/savevm.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/migration/savevm.c b/migration/savevm.c index 2d10e45582..9cb97ca343 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1319,21 +1319,18 @@ 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_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); @@ -1355,7 +1352,6 @@ 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 { -- 2.13.2.windows.1
