[PATCH] RISC-V: KVM: fix off-by-one array access in SBI PMU

[Radim Krčmář]

The indexed array only has RISCV_KVM_MAX_COUNTERS elements.
The out-of-bound access could have been performed by a guest, but it
could only access another guest accessible data.

Fixes: 8f0153ecd3bf ("RISC-V: KVM: Add skeleton support for perf")
Signed-off-by: Radim Krčmář <radim.krcmar@xxxxxxxxxxxxxxxx>
---
 arch/riscv/kvm/vcpu_pmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
index 4d8d5e9aa53d..aec6b293968b 100644
--- a/arch/riscv/kvm/vcpu_pmu.c
+++ b/arch/riscv/kvm/vcpu_pmu.c
@@ -520,7 +520,7 @@ int kvm_riscv_vcpu_pmu_ctr_info(struct kvm_vcpu *vcpu, unsigned long cidx,
 {
 	struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu);
 
-	if (cidx > RISCV_KVM_MAX_COUNTERS || cidx == 1) {
+	if (cidx >= RISCV_KVM_MAX_COUNTERS || cidx == 1) {
 		retdata->err_val = SBI_ERR_INVALID_PARAM;
 		return 0;
 	}
-- 
2.51.2