[PATCH v2 0/2] KVM: x86: Fix UBSAN bool warnings in module parameters

From: Gal Pressman

Date: Wed Feb 25 2026 - 09:51:25 EST


Several KVM module parameters use int to support a special -1 (auto)
value, but rely on param_get_bool() for the sysfs getter.
When userspace reads these parameters before the auto value is resolved,
param_get_bool() interprets the int as a bool, triggering UBSAN "load of
value 255 is not a valid value for type '_Bool'" warnings.

Fix both instances by implementing getter functions that handle the -1
case before falling through to param_get_bool().

Changelog -
v1->v2: https://lore.kernel.org/all/20260210064621.1902269-1-gal@xxxxxxxxxx/
* Show auto avic as 'N' (Naveen)

Gal Pressman (2):
KVM: SVM: Fix UBSAN warning when reading avic parameter
KVM: x86/mmu: Fix UBSAN warning when reading nx_huge_pages parameter

arch/x86/kvm/mmu/mmu.c | 5 +++++
arch/x86/kvm/svm/avic.c | 13 ++++++++++++-
2 files changed, 17 insertions(+), 1 deletion(-)

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2.52.0