diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
index 7de128be8db9b..6e704ed86a83a 100644
--- a/arch/riscv/kvm/vcpu_sbi.c
+++ b/arch/riscv/kvm/vcpu_sbi.c
@@ -486,19 +486,22 @@ void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu)
 	struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
 	const struct kvm_riscv_sbi_extension_entry *entry;
 	const struct kvm_vcpu_sbi_extension *ext;
-	int i;
+	int idx, i;
 
 	for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
 		entry = &sbi_ext[i];
 		ext = entry->ext_ptr;
+		idx = entry->ext_idx;
+
+		if (idx < 0 || idx >= ARRAY_SIZE(scontext->ext_status))
+			continue;
 
 		if (ext->probe && !ext->probe(vcpu)) {
-			scontext->ext_status[entry->ext_idx] =
-				KVM_RISCV_SBI_EXT_STATUS_UNAVAILABLE;
+			scontext->ext_status[idx] = KVM_RISCV_SBI_EXT_STATUS_UNAVAILABLE;
 			continue;
 		}
 
-		scontext->ext_status[entry->ext_idx] = ext->default_disabled ?
+		scontext->ext_status[idx] = ext->default_disabled ?
 					KVM_RISCV_SBI_EXT_STATUS_DISABLED :
 					KVM_RISCV_SBI_EXT_STATUS_ENABLED;
 	}