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authorAvi Kivity <avi@qumranet.com>2007-11-21 16:41:05 +0200
committerAvi Kivity <avi@qumranet.com>2008-01-30 17:53:13 +0200
commit6d4e4c4fca5be806b888d606894d914847e82d78 (patch)
treedc383e27d812f617d791f48ba1527d70c86b65ba /drivers/kvm/kvm_main.c
parentKVM: MMU: Rename 'release_page' (diff)
downloadlinux-dev-6d4e4c4fca5be806b888d606894d914847e82d78.tar.xz
linux-dev-6d4e4c4fca5be806b888d606894d914847e82d78.zip
KVM: Disallow fork() and similar games when using a VM
We don't want the meaning of guest userspace changing under our feet. Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'drivers/kvm/kvm_main.c')
-rw-r--r--drivers/kvm/kvm_main.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index aec6b67cfebb..0efd759e585f 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -165,6 +165,8 @@ static struct kvm *kvm_create_vm(void)
if (IS_ERR(kvm))
goto out;
+ kvm->mm = current->mm;
+ atomic_inc(&kvm->mm->mm_count);
kvm_io_bus_init(&kvm->pio_bus);
mutex_init(&kvm->lock);
kvm_io_bus_init(&kvm->mmio_bus);
@@ -202,12 +204,15 @@ void kvm_free_physmem(struct kvm *kvm)
static void kvm_destroy_vm(struct kvm *kvm)
{
+ struct mm_struct *mm = kvm->mm;
+
spin_lock(&kvm_lock);
list_del(&kvm->vm_list);
spin_unlock(&kvm_lock);
kvm_io_bus_destroy(&kvm->pio_bus);
kvm_io_bus_destroy(&kvm->mmio_bus);
kvm_arch_destroy_vm(kvm);
+ mmdrop(mm);
}
static int kvm_vm_release(struct inode *inode, struct file *filp)
@@ -818,6 +823,8 @@ static long kvm_vcpu_ioctl(struct file *filp,
void __user *argp = (void __user *)arg;
int r;
+ if (vcpu->kvm->mm != current->mm)
+ return -EIO;
switch (ioctl) {
case KVM_RUN:
r = -EINVAL;
@@ -976,6 +983,8 @@ static long kvm_vm_ioctl(struct file *filp,
void __user *argp = (void __user *)arg;
int r;
+ if (kvm->mm != current->mm)
+ return -EIO;
switch (ioctl) {
case KVM_CREATE_VCPU:
r = kvm_vm_ioctl_create_vcpu(kvm, arg);