From nobody Fri May 3 21:29:08 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of redhat.com designates 209.132.183.28 as permitted sender) client-ip=209.132.183.28; envelope-from=libvir-list-bounces@redhat.com; helo=mx1.redhat.com; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=libvir-list-bounces@redhat.com; dmarc=pass(p=none dis=none) header.from=redhat.com Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by mx.zohomail.com with SMTPS id 1533458855108959.3631851933753; Sun, 5 Aug 2018 01:47:35 -0700 (PDT) Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7BE79C015C2E; Sun, 5 Aug 2018 08:47:33 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 46FAB61359; Sun, 5 Aug 2018 08:47:33 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id F30954EE1F; Sun, 5 Aug 2018 08:47:32 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id w727ZugJ020327 for ; Thu, 2 Aug 2018 03:35:57 -0400 Received: by smtp.corp.redhat.com (Postfix) id D2D191C702; Thu, 2 Aug 2018 07:35:56 +0000 (UTC) Received: from moe.brq.redhat.com (unknown [10.43.2.192]) by smtp.corp.redhat.com (Postfix) with ESMTP id 71C291C710 for ; Thu, 2 Aug 2018 07:35:54 +0000 (UTC) From: Michal Privoznik To: libvir-list@redhat.com Date: Thu, 2 Aug 2018 09:35:49 +0200 Message-Id: X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-loop: libvir-list@redhat.com Subject: [libvirt] [PATCH] virrandom: Avoid undefined behaviour in virRandomBits X-BeenThere: libvir-list@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: Development discussions about the libvirt library & tools List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: libvir-list-bounces@redhat.com Errors-To: libvir-list-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Sun, 05 Aug 2018 08:47:34 +0000 (UTC) X-ZohoMail: RDMRC_0 RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" If nbits is 64 (or greater) then shifting 1ULL left is undefined. Signed-off-by: Michal Privoznik Reviewed-by: Daniel P. Berrang=C3=A9 --- src/util/virrandom.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/util/virrandom.c b/src/util/virrandom.c index 3c011a8615..7915f6531e 100644 --- a/src/util/virrandom.c +++ b/src/util/virrandom.c @@ -68,7 +68,9 @@ uint64_t virRandomBits(int nbits) return 0; } =20 - ret &=3D (1ULL << nbits) - 1; + if (nbits < 64) + ret &=3D (1ULL << nbits) - 1; + return ret; } =20 --=20 2.16.4 -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list