From: Paul Mackerras <paulus@xxxxxxxxx> Commit 55b665b026 ("KVM: PPC: Book3S HV: Provide a way for userspace to get/set per-vCPU areas") includes a check on the length of the dispatch trace log (DTL) to make sure the buffer is at least one entry long. This is appropriate when registering a buffer, but the interface also allows for any existing buffer to be unregistered by specifying a zero address. In this case the length check is not appropriate. This makes the check conditional on the address being non-zero. Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx> Signed-off-by: Alexander Graf <agraf@xxxxxxx> --- arch/powerpc/kvm/book3s_hv.c | 5 ++--- 1 files changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 8b3c470..812764c 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -811,9 +811,8 @@ int kvmppc_set_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val) addr = val->vpaval.addr; len = val->vpaval.length; r = -EINVAL; - if (len < sizeof(struct dtl_entry)) - break; - if (addr && !vcpu->arch.vpa.next_gpa) + if (addr && (len < sizeof(struct dtl_entry) || + !vcpu->arch.vpa.next_gpa)) break; len -= len % sizeof(struct dtl_entry); r = set_vpa(vcpu, &vcpu->arch.dtl, addr, len); -- 1.6.0.2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html