From patchwork Fri Dec 18 19:09:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrea Claudi X-Patchwork-Id: 11982825 X-Patchwork-Delegate: dsahern@gmail.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8960CC4361B for ; Fri, 18 Dec 2020 19:16:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D9E223B84 for ; Fri, 18 Dec 2020 19:16:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733184AbgLRTQC (ORCPT ); Fri, 18 Dec 2020 14:16:02 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:39295 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733170AbgLRTQB (ORCPT ); Fri, 18 Dec 2020 14:16:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608318874; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1A5KnGNmwF5n0yn9HURhvCq30IxDsuKeH4KfEcyOkvs=; b=M6NJ4dud4pFblN/TvN3LoG3/DRs42S9+AXw2fmqU1XbEMJeNsBYXwqNyVZgzsbN++kKJyd rRIZYYmZW6pXNIVDShNKrQI+c45Uv/VclReiLT7zDrvlxHoFqGQBc/xaAlO+r6OA6vc5xO RL8ozbA44t8pAR+bE04/APHBbK1CtTM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-422-GvrgJq7WPmehweBZcBw9qA-1; Fri, 18 Dec 2020 14:14:33 -0500 X-MC-Unique: GvrgJq7WPmehweBZcBw9qA-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 399E4802B40; Fri, 18 Dec 2020 19:14:32 +0000 (UTC) Received: from localhost.localdomain (ovpn-114-0.ams2.redhat.com [10.36.114.0]) by smtp.corp.redhat.com (Postfix) with ESMTP id 655C12C01B; Fri, 18 Dec 2020 19:14:31 +0000 (UTC) From: Andrea Claudi To: netdev@vger.kernel.org Cc: stephen@networkplumber.org, dsahern@gmail.com Subject: [PATCH iproute2 2/2] lib/fs: Fix single return points for get_cgroup2_* Date: Fri, 18 Dec 2020 20:09:23 +0100 Message-Id: <9b07b59c4c422b29d6c8297f7f7ec0f2dcc7fb3f.1608315719.git.aclaudi@redhat.com> In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: dsahern@gmail.com Functions get_cgroup2_id() and get_cgroup2_path() uncorrectly performs cleanup on the single return point. Both of them may get to use close() with a negative argument, if open() fails. Fix this adding proper labels and gotos to make sure we clean up only resources we are effectively used before. Fixes: d5e6ee0dac64 ("ss: introduce cgroup2 cache and helper functions") Fixes: 8f1cd119b377 ("lib: fix checking of returned file handle size for cgroup") Signed-off-by: Andrea Claudi --- lib/fs.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/lib/fs.c b/lib/fs.c index 2ae506ec..77414e99 100644 --- a/lib/fs.c +++ b/lib/fs.c @@ -139,27 +139,31 @@ __u64 get_cgroup2_id(const char *path) mnt_fd = open(mnt, O_RDONLY); if (mnt_fd < 0) { fprintf(stderr, "Failed to open cgroup2 mount\n"); - goto out; + goto out_clean_mnt; } fhp->handle_bytes = sizeof(__u64); if (name_to_handle_at(mnt_fd, path, fhp, &mnt_id, 0) < 0) { fprintf(stderr, "Failed to get cgroup2 ID: %s\n", strerror(errno)); - goto out; + goto out_clean_all; } } if (fhp->handle_bytes != sizeof(__u64)) { fprintf(stderr, "Invalid size of cgroup2 ID\n"); - goto out; + if (mnt_fd < 0) + goto out; + goto out_clean_all; } memcpy(cg_id.bytes, fhp->f_handle, sizeof(__u64)); -out: +out_clean_all: close(mnt_fd); +out_clean_mnt: free(mnt); +out: return cg_id.id; } @@ -183,17 +187,17 @@ char *get_cgroup2_path(__u64 id, bool full) if (!id) { fprintf(stderr, "Invalid cgroup2 ID\n"); - return NULL; + goto out; } mnt = find_cgroup2_mount(false); if (!mnt) - return NULL; + goto out; mnt_fd = open(mnt, O_RDONLY); if (mnt_fd < 0) { fprintf(stderr, "Failed to open cgroup2 mount\n"); - goto out; + goto out_clean_mnt; } fhp->handle_bytes = sizeof(__u64); @@ -203,7 +207,7 @@ char *get_cgroup2_path(__u64 id, bool full) fd = open_by_handle_at(mnt_fd, fhp, 0); if (fd < 0) { fprintf(stderr, "Failed to open cgroup2 by ID\n"); - goto out; + goto out_clean_mntfd; } snprintf(fd_path, sizeof(fd_path), "/proc/self/fd/%d", fd); @@ -212,7 +216,7 @@ char *get_cgroup2_path(__u64 id, bool full) fprintf(stderr, "Failed to read value of symbolic link %s\n", fd_path); - goto out; + goto out_clean_all; } link_buf[link_len] = '\0'; @@ -224,11 +228,14 @@ char *get_cgroup2_path(__u64 id, bool full) fprintf(stderr, "Failed to allocate memory for cgroup2 path\n"); -out: +out_clean_all: close(fd); +out_clean_mntfd: close(mnt_fd); +out_clean_mnt: free(mnt); +out: return path; }