From 211c0189ea18648a0cf23dea9f4ed745bc9252f6 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 11 Jul 2023 16:01:31 -0700 Subject: [PATCH] KVM: selftests: Verify stats fd is usable after VM fd has been closed Verify that VM and vCPU binary stats files are usable even after userspace has put its last direct reference to the VM. This is a regression test for a UAF bug where KVM didn't gift the stats files a reference to the VM. Signed-off-by: Sean Christopherson Message-Id: <20230711230131.648752-8-seanjc@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/kvm_binary_stats_test.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/kvm/kvm_binary_stats_test.c b/tools/testing/selftests/kvm/kvm_binary_stats_test.c index 5317e27..698c1cf 100644 --- a/tools/testing/selftests/kvm/kvm_binary_stats_test.c +++ b/tools/testing/selftests/kvm/kvm_binary_stats_test.c @@ -252,6 +252,14 @@ int main(int argc, char *argv[]) stats_test(vcpu_get_stats_fd(vcpus[i * max_vcpu + j])); } + /* + * Close the VM fd and redo the stats tests. KVM should gift a + * reference (to the VM) to each stats fd, i.e. stats should + * still be accessible even after userspace has put its last + * _direct_ reference to the VM. + */ + kvm_vm_free(vms[i]); + stats_test(vm_stats_fds); for (j = 0; j < max_vcpu; ++j) stats_test(vcpu_stats_fds[j]); @@ -259,8 +267,6 @@ int main(int argc, char *argv[]) ksft_test_result_pass("vm%i\n", i); } - for (i = 0; i < max_vm; ++i) - kvm_vm_free(vms[i]); free(vms); free(vcpus); free(vcpu_stats_fds); -- 2.7.4