From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751875AbeDINKd (ORCPT ); Mon, 9 Apr 2018 09:10:33 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:33112 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751367AbeDINKc (ORCPT ); Mon, 9 Apr 2018 09:10:32 -0400 From: Stefan Hajnoczi To: virtualization@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, jasowang@redhat.com, kvm@vger.kernel.org, mst@redhat.com, syzkaller-bugs@googlegroups.com, Stefan Hajnoczi Subject: [PATCH] vhost: fix vhost_vq_access_ok() log check Date: Mon, 9 Apr 2018 21:10:21 +0800 Message-Id: <20180409131021.5132-1-stefanha@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit d65026c6c62e7d9616c8ceb5a53b68bcdc050525 ("vhost: validate log when IOTLB is enabled") introduced a regression. The logic was originally: if (vq->iotlb) return 1; return A && B; After the patch the short-circuit logic for A was inverted: if (A || vq->iotlb) return A; return B; The correct logic is: if (!A || vq->iotlb) return A; return B; Reported-by: syzbot+65a84dde0214b0387ccd@syzkaller.appspotmail.com Cc: Jason Wang Signed-off-by: Stefan Hajnoczi --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 5320039671b7..f6af4210679a 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1246,7 +1246,7 @@ int vhost_vq_access_ok(struct vhost_virtqueue *vq) { int ret = vq_log_access_ok(vq, vq->log_base); - if (ret || vq->iotlb) + if (!ret || vq->iotlb) return ret; return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); -- 2.14.3