This is a note to let you know that I've just added the patch titled

virt: acrn: Do hcall_destroy_vm() before resource release

to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 4c4c1257b844ffe5d0933684e612f92c4b78e120 Mon Sep 17 00:00:00 2001

From: Shuo Liu shuo.a.liu@intel.com Date: Thu, 22 Jul 2021 14:27:36 +0800 Subject: virt: acrn: Do hcall_destroy_vm() before resource release

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@vger.kernel.org Signed-off-by: Shuo Liu shuo.a.liu@intel.com Signed-off-by: Fei Li fei1.li@intel.com Link: https://lore.kernel.org/r/20210722062736.15050-1-fei1.li@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/virt/acrn/vm.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/virt/acrn/vm.c b/drivers/virt/acrn/vm.c index 0d002a355a93..fbc9f1042000 100644 --- 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);