From e00a58c10aa6a8f4b6ba6f9611bee4cd66869bda Mon Sep 17 00:00:00 2001 From: Peter Krempa Date: Thu, 13 Jun 2024 16:21:47 +0200 Subject: [PATCH] qemuMigrationSrcRun: Re-check whether VM is active before accessing job data 'qemuProcessStop()' clears the 'current' job data. While the code under the 'error' label in 'qemuMigrationSrcRun()' does check that the VM is active before accessing the job, it also invokes multiple helper functions to clean up the migration including 'qemuMigrationSrcNBDCopyCancel()' which calls 'qemuDomainObjWait()' invalidating the result of the liveness check as it unlocks the VM. Duplicate the liveness check and explain why. The rest of the code e.g. accessing the monitor is safe as 'qemuDomainEnterMonitorAsync()' performs a liveness check. The cleanup path just ignores the return values of those functions. Signed-off-by: Peter Krempa Reviewed-by: Michal Privoznik --- src/qemu/qemu_migration.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 3524915e9d..89ddc586bd 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -5074,7 +5074,13 @@ qemuMigrationSrcRun(virQEMUDriver *driver, dconn); qemuMigrationSrcCancelRemoveTempBitmaps(vm, VIR_ASYNC_JOB_MIGRATION_OUT); + } + /* We need to re-check that the VM is active as functions like + * qemuMigrationSrcCancel/qemuMigrationSrcNBDCopyCancel wait on the VM + * condition unlocking the VM object which can lead to a cleanup of the + * 'current' job via qemuProcessStop */ + if (qemuDomainObjIsActive(vm)) { if (vm->job->current->status != VIR_DOMAIN_JOB_STATUS_CANCELED) vm->job->current->status = VIR_DOMAIN_JOB_STATUS_FAILED; }