From 49d9d295d69d07e850cae35933ba8519e2915f26 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Mon, 14 Sep 2026 10:38:38 +0100 Subject: [PATCH] KVM: arm64: Don't WARN on an unknown VM ioctl in protected mode kvm_pkvm_ioctl_allowed() WARNs when kvm_get_cap_for_kvm_ioctl() doesn't find the ioctl number in vm_ioctl_caps[], and kvm_arch_vm_ioctl() calls it for every number the generic code doesn't handle, so ioctl(vm_fd, 0xdeadbeef) from userspace taints a pKVM host and panics it under panic_on_warn. The lookup is fed userspace input: return false, and userspace gets the -EINVAL kvm_arch_vm_ioctl() returns for that number on a host without pKVM. Fixes: b12b3b04f6ba0 ("KVM: arm64: Check whether a VM IOCTL is allowed in pKVM") Cc: stable@vger.kernel.org Signed-off-by: Fuad Tabba Reviewed-by: Suzuki K Poulose Link: https://patch.msgid.link/20260914093838.1082637-1-fuad.tabba@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/include/asm/kvm_pkvm.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h index beea00e693a0..cad60569f061 100644 --- a/arch/arm64/include/asm/kvm_pkvm.h +++ b/arch/arm64/include/asm/kvm_pkvm.h @@ -65,8 +65,7 @@ static inline bool kvm_pkvm_ioctl_allowed(struct kvm *kvm, unsigned int ioctl) int r; r = kvm_get_cap_for_kvm_ioctl(ioctl, &ext); - - if (WARN_ON_ONCE(r < 0)) + if (r < 0) return false; return kvm_pkvm_ext_allowed(kvm, ext);