From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 30 Nov 2016 19:21:05 +0000 (+0300)
Subject: KVM: use after free in kvm_ioctl_create_device()
X-Git-Tag: v4.8.13~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6c69476139799ccf8d3e76edfc892c64ced80bc4;p=thirdparty%2Fkernel%2Fstable.git

KVM: use after free in kvm_ioctl_create_device()

commit a0f1d21c1ccb1da66629627a74059dd7f5ac9c61 upstream.

We should move the ops->destroy(dev) after the list_del(&dev->vm_node)
so that we don't use "dev" after freeing it.

Fixes: a28ebea2adc4 ("KVM: Protect device ops->create and list_add with kvm->lock")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 195078225aa5d..690d15eaee05f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2852,10 +2852,10 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
 
 	ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC);
 	if (ret < 0) {
-		ops->destroy(dev);
 		mutex_lock(&kvm->lock);
 		list_del(&dev->vm_node);
 		mutex_unlock(&kvm->lock);
+		ops->destroy(dev);
 		return ret;
 	}