Received: by 10.223.185.116 with SMTP id b49csp1078947wrg; Fri, 23 Feb 2018 11:32:13 -0800 (PST) X-Google-Smtp-Source: AH8x227qsAA2sn63Y2OR8rZZBICpOZ2lnZTnFcIlYRz6Gbz5sk/67olycm+YK0PZOUg2onDoM5VU X-Received: by 2002:a17:902:4643:: with SMTP id o61-v6mr2727924pld.103.1519414333064; Fri, 23 Feb 2018 11:32:13 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1519414333; cv=none; d=google.com; s=arc-20160816; b=tXTKXwuDaqLkGpKKbWdtUShprd8FF8wVUZP01G7NIXibObXFyeqsKS4k+zrWQoX4Rl Kb+5qx2BGoenqacd6XieXFctK/spe+kC2YyBZRNm5MZeMeEW/hhJSwkw4TpYtCcibM+X 0DamuR+L/g0oyqs4tbAgzYe+dtbyV5u5ovV0LVJRbza7FKGKJtO+cIbClqqYDp+rIZCU Mp9z0IIXWUuNz/E/42eaOZjZBCUfZicnEPnh1DZdj+dppAsKMdyrUqt+AqM67g/1Jvt3 EORrB8X/UDq+oIbYWFbdRO+lAHLHdFyC8F0dI8uVebK7oJNiKLQDpOgtva+PTbUwY94D 2Dqw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:user-agent:references :in-reply-to:message-id:date:subject:cc:to:from :arc-authentication-results; bh=lzcBUgR7H61xNF2jlQbg3NYuuQLL1fxTGV4CLQLs+ko=; b=eH8MNPKODG2uOyJl9O6260H6gx8xA2JJUsWsUCG4VBL6nVLELwGBr9javBEIRJCfSR YcNSl9RDRBu5ThspURz0OloLiVkBkZvSK4yIQl5yiQweqO99dfoVqjO82xVmTbxJPg2N xE56aZROeYKIcvvBsAxjjpcmMlsYGf7GoCU0QBfbVMO4wpaWuyrMDPt4siU8Xi5BEbqW A9DMh87TFu75G31Xb5nM3sQnfCHNLwhH2w7GFdENSytYK4ie+gGWWnJPg4v++C4Zitr+ OoDQTqRzGRjVfXR9CZKG6vyYZoqyEQBBZ1ekvqRqGTrwJWTfJkoqfci3bjBr3QRlHkp+ 9U8Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id f8si1870987pgs.52.2018.02.23.11.31.58; Fri, 23 Feb 2018 11:32:13 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934978AbeBWSvc (ORCPT + 99 others); Fri, 23 Feb 2018 13:51:32 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:46032 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934552AbeBWSv3 (ORCPT ); Fri, 23 Feb 2018 13:51:29 -0500 Received: from localhost (LFbn-1-12258-90.w90-92.abo.wanadoo.fr [90.92.71.90]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id EA71F12E2; Fri, 23 Feb 2018 18:51:28 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dmitry Vyukov , Shankara Pailoor , syzbot , Andrew Morton , Linus Torvalds Subject: [PATCH 4.14 034/159] kcov: detect double association with a single task Date: Fri, 23 Feb 2018 19:25:42 +0100 Message-Id: <20180223170747.514302346@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180223170743.086611315@linuxfoundation.org> References: <20180223170743.086611315@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Vyukov commit a77660d231f8b3d84fd23ed482e0964f7aa546d6 upstream. Currently KCOV_ENABLE does not check if the current task is already associated with another kcov descriptor. As the result it is possible to associate a single task with more than one kcov descriptor, which later leads to a memory leak of the old descriptor. This relation is really meant to be one-to-one (task has only one back link). Extend validation to detect such misuse. Link: http://lkml.kernel.org/r/20180122082520.15716-1-dvyukov@google.com Fixes: 5c9a8750a640 ("kernel: add kcov code coverage") Signed-off-by: Dmitry Vyukov Reported-by: Shankara Pailoor Cc: Dmitry Vyukov Cc: syzbot Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- kernel/kcov.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -225,9 +225,9 @@ static int kcov_ioctl_locked(struct kcov if (unused != 0 || kcov->mode == KCOV_MODE_DISABLED || kcov->area == NULL) return -EINVAL; - if (kcov->t != NULL) - return -EBUSY; t = current; + if (kcov->t != NULL || t->kcov != NULL) + return -EBUSY; /* Cache in task struct for performance. */ t->kcov_size = kcov->size; t->kcov_area = kcov->area;