Merge tag 'kvm-x86-fixes-6.10-11' of https://github.com/kvm-x86/linux into HEAD

KVM Xen:

Fix a bug where KVM fails to check the validity of an incoming userspace
virtual address and tries to activate a gfn_to_pfn_cache with a kernel address.

Author: bonzini

arch/x86/kvm/xen.c

@@ -741,7 +741,7 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 		} else {
 			void __user * hva = u64_to_user_ptr(data->u.shared_info.hva);
 
-			if (!PAGE_ALIGNED(hva) || !access_ok(hva, PAGE_SIZE)) {
+			if (!PAGE_ALIGNED(hva)) {
 				r = -EINVAL;
 			} else if (!hva) {
 				kvm_gpc_deactivate(&kvm->arch.xen.shinfo_cache);

virt/kvm/pfncache.c

@@ -430,6 +430,9 @@ int kvm_gpc_activate(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len)
 
 int kvm_gpc_activate_hva(struct gfn_to_pfn_cache *gpc, unsigned long uhva, unsigned long len)
 {
+	if (!access_ok((void __user *)uhva, len))
+		return -EINVAL;
+
 	return __kvm_gpc_activate(gpc, INVALID_GPA, uhva, len);
 }