KVM: x86/xen: Fix memory leak in kvm_xen_write_hypercall_page()

Release page irrespectively of kvm_vcpu_write_guest() return value.

Suggested-by: Paul Durrant <paul@xen.org>
Fixes: 23200b7a30de ("KVM: x86/xen: intercept xen hypercalls if enabled")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Message-Id: <20221220151454.712165-1-mhal@rbox.co>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>

diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index d7af402402484bb008f253213a86c186224a34c1..d1a98d834d185f43f4ab30fc29359b1bfa51f69a 100644 (file)
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -1069,6 +1069,7 @@ int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data)
                u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64
                                  : kvm->arch.xen_hvm_config.blob_size_32;
                u8 *page;
+               int ret;
 
                if (page_num >= blob_size)
                        return 1;
@@ -1079,10 +1080,10 @@ int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data)
                if (IS_ERR(page))
                        return PTR_ERR(page);
 
-               if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE)) {
-                       kfree(page);
+               ret = kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE);
+               kfree(page);
+               if (ret)
                        return 1;
-               }
        }
        return 0;
 }