[PATCH 5.13 133/175] virt: acrn: Do hcall_destroy_vm() before resource release

From: Greg Kroah-Hartman
Date: Tue Aug 10 2021 - 14:07:43 EST


From: Shuo Liu <shuo.a.liu@xxxxxxxxx>

commit 4c4c1257b844ffe5d0933684e612f92c4b78e120 upstream.

The ACRN hypervisor has scenarios which could run a real-time guest VM.
The real-time guest VM occupies dedicated CPU cores, be assigned with
dedicated PCI devices. It can run without the Service VM after boot up.
hcall_destroy_vm() returns failure when a real-time guest VM refuses.
The clearing of flag ACRN_VM_FLAG_DESTROYED causes some kernel resource
double-freed in a later acrn_vm_destroy().

Do hcall_destroy_vm() before resource release to drop this chance to
destroy the VM if hypercall fails.

Fixes: 9c5137aedd11 ("virt: acrn: Introduce VM management interfaces")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Shuo Liu <shuo.a.liu@xxxxxxxxx>
Signed-off-by: Fei Li <fei1.li@xxxxxxxxx>
Link: https://lore.kernel.org/r/20210722062736.15050-1-fei1.li@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/virt/acrn/vm.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

--- a/drivers/virt/acrn/vm.c
+++ b/drivers/virt/acrn/vm.c
@@ -64,6 +64,14 @@ int acrn_vm_destroy(struct acrn_vm *vm)
test_and_set_bit(ACRN_VM_FLAG_DESTROYED, &vm->flags))
return 0;

+ ret = hcall_destroy_vm(vm->vmid);
+ if (ret < 0) {
+ dev_err(acrn_dev.this_device,
+ "Failed to destroy VM %u\n", vm->vmid);
+ clear_bit(ACRN_VM_FLAG_DESTROYED, &vm->flags);
+ return ret;
+ }
+
/* Remove from global VM list */
write_lock_bh(&acrn_vm_list_lock);
list_del_init(&vm->list);
@@ -78,14 +86,6 @@ int acrn_vm_destroy(struct acrn_vm *vm)
vm->monitor_page = NULL;
}

- ret = hcall_destroy_vm(vm->vmid);
- if (ret < 0) {
- dev_err(acrn_dev.this_device,
- "Failed to destroy VM %u\n", vm->vmid);
- clear_bit(ACRN_VM_FLAG_DESTROYED, &vm->flags);
- return ret;
- }
-
acrn_vm_all_ram_unmap(vm);

dev_dbg(acrn_dev.this_device, "VM %u destroyed.\n", vm->vmid);