[PATCH v6 3/5] selftests: kvm: s390: Verify reject memory region operations for ucontrol VMs

Christoph Schlameuss
2024-10-15T08:37:58Z

Add a test case verifying KVM_SET_USER_MEMORY_REGION and
KVM_SET_USER_MEMORY_REGION2 cannot be executed on ucontrol VMs.

Executing this test case on not patched kernels will cause a null
pointer dereference in the host kernel.
This is fixed with commit:
commit 7816e58967d0 ("kvm: s390: Reject memory region operations for ucontrol VMs")

Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
---
.../selftests/kvm/s390x/ucontrol_test.c | 22 +++++++++++++++++++
1 file changed, 22 insertions(+)

diff --git a/tools/testing/selftests/kvm/s390x/ucontrol_test.c b/tools/testing/selftests/kvm/s390x/ucontrol_test.c
index 9568a4e03e4b..ae077bf838c8 100644
--- a/tools/testing/selftests/kvm/s390x/ucontrol_test.c
+++ b/tools/testing/selftests/kvm/s390x/ucontrol_test.c
@@ -439,6 +439,28 @@ static void uc_assert_diag44(FIXTURE_DATA(uc_kvm) * self)
TEST_ASSERT_EQ(0x440000, sie_block->ipb);
}

+TEST_F(uc_kvm, uc_no_user_region)
+{
+ struct kvm_userspace_memory_region region = {
+ .slot = 1,
+ .guest_phys_addr = self->code_gpa,
+ .memory_size = VM_MEM_EXT_SIZE,
+ .userspace_addr = (uintptr_t)self->code_hva,
+ };
+ struct kvm_userspace_memory_region2 region2 = {
+ .slot = 1,
+ .guest_phys_addr = self->code_gpa,
+ .memory_size = VM_MEM_EXT_SIZE,
+ .userspace_addr = (uintptr_t)self->code_hva,
+ };
+
+ ASSERT_EQ(-1, ioctl(self->vm_fd, KVM_SET_USER_MEMORY_REGION, &region));
+ ASSERT_EQ(EINVAL, errno);
+
+ ASSERT_EQ(-1, ioctl(self->vm_fd, KVM_SET_USER_MEMORY_REGION2, &region2));
+ ASSERT_EQ(EINVAL, errno);
+}
+
TEST_F(uc_kvm, uc_map_unmap)
{
struct kvm_sync_regs *sync_regs = &self->run->s.regs;
--
2.47.0