[PATCH v2 0/2] KVM: selftests: Fix two VMs leaked on early returns

From: Gokul K

Date: Tue Aug 11 2026 - 01:00:57 EST


Two x86 selftests create a VM and then take an early return that skips the
kvm_vm_free() at the end of the function. Both now jump to that existing
cleanup instead.

Patch 1 is the plain-SEV path of sev_smoke_test(), which returns straight
out of the UCALL_DONE case instead of leaving the loop. The SEV-ES path
next to it breaks out and frees correctly.

Patch 2 is nx_huge_pages_test, which returns as soon as it has confirmed
that disabling NX huge pages is denied without CAP_SYS_BOOT.

The two patches are independent and either can be applied on its own.

Found by auditing every function under tools/testing/selftests/kvm/ that
creates a VM and later calls kvm_vm_free(), looking for returns in
between. Seven other hits were false positives, mostly returns after
REPORT_GUEST_ASSERT() or TEST_FAIL(), which abort the process and make the
return unreachable. Two more that do look real, in get-reg-list.c and
arm64/external_aborts.c, are left out because they belong to different
maintainers.

Compile-tested only. This host has neither SEV (kvm_amd sev=N) nor hugetlb
configured, so both tests SKIP rather than run.

Note patch 1 touches sev_smoke_test.c, which an unrelated patch I sent
earlier also touches [1]. They modify different functions and do not
conflict in either order.

v2:
- nx_huge_pages_test: goto the existing cleanup instead of open-coding
kvm_vm_free() before the return, matching patch 1 (Sean)
- Drop the claims that these paths never exercise VM teardown, and that
the nx_huge_pages path is not obscure. Neither justification holds
up: teardown still happens, just at process exit, and how often a
leaking path runs does not change whether it should be fixed (Sean)
- Rebase onto current kvm-x86/next

[1] https://lore.kernel.org/all/20260807071026.195503-1-gokul02k@xxxxxxxxx/
v1: https://lore.kernel.org/all/20260808081050.408657-1-gokul02k@xxxxxxxxx/

Gokul K (2):
KVM: selftests: Free the VM when the SEV smoke test's guest completes
KVM: selftests: Free the VM when NX hugepage disabling is denied

tools/testing/selftests/kvm/x86/nx_huge_pages_test.c | 3 ++-
tools/testing/selftests/kvm/x86/sev_smoke_test.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)

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2.54.0