From patchwork Thu Mar 4 21:29:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Moore X-Patchwork-Id: 12116809 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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 AE67AC433DB for ; Thu, 4 Mar 2021 21:31:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EB8264FE8 for ; Thu, 4 Mar 2021 21:31:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239689AbhCDVap (ORCPT ); Thu, 4 Mar 2021 16:30:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41252 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236664AbhCDVae (ORCPT ); Thu, 4 Mar 2021 16:30:34 -0500 Received: from mail-qv1-xf30.google.com (mail-qv1-xf30.google.com [IPv6:2607:f8b0:4864:20::f30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F26D3C061756 for ; Thu, 4 Mar 2021 13:29:53 -0800 (PST) Received: by mail-qv1-xf30.google.com with SMTP id 2so14353021qvd.0 for ; Thu, 04 Mar 2021 13:29:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=paul-moore-com.20150623.gappssmtp.com; s=20150623; h=subject:from:to:cc:date:message-id:user-agent:mime-version :content-transfer-encoding; bh=x4Z+DisI/8o2HYT+CH6xxotXu806Acbm+rcHwITIcF4=; b=LKOLjajsWej/VvbaJrfgnDS8nl8lXk2eR1wWHPrZNYJGajh1g/xYlRCIDYHOKSFBSG RDiQRtzKhyn44xj9nSowEDjNAGSEopsVNLWWiCATCxCLB4ETqiV8h/sM2Aix+3onQ1d8 OhFEmYiF3xBdtg2GAWW14TABFhd+sv/IhK1LbUxTTxWa+RA/uz/OxDNofkNgZMer4qMA af4VkYvUCrjyfcIz7flYEXRukNYm2vnoUOomQNiYugbP+YqCGlkL1u1EKICnt3IFL8VU 9Wwa+CoQJjFGP6qr0Oo5v5sKP9mUS+pE8u+9lyXOz7wLirRScdOXdvcFuNav9ZIZVRzH UiNg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:date:message-id:user-agent :mime-version:content-transfer-encoding; bh=x4Z+DisI/8o2HYT+CH6xxotXu806Acbm+rcHwITIcF4=; b=LzIJCoDVgx2VL5PfvV15g99PW+B4MGIDXP0yXu1BHjqmtdTQkJ8AFGQfKYDKm0kQBf XsdRfVZnoM2mAwk9SBPgBaxATBh36gSZlvKt4vlcNnLUvzqZdUrmjZlkq5ln271caVdn uKv+z7Zf7zDyqSPv7mu4X30gV0TaUhQqDya0CgEFVvKyvGuby6RKYsYW4rKMTWLw+rPt gIA6pO+3CXyY+c6IiqDyMzxcDim/Ae33B1N1tPPSptAsLe8yjluuZjhv/qBBz8yViBN3 yqnPFBQENejjzXA6jGc1/ErKB/hqVtvgduBj2cS5vCVzKn9g+/ccJiK179WU33dTMU3e Sxcw== X-Gm-Message-State: AOAM531CIimLSCHvvaA9V6aAAMGd7T+SGnOPNvGBBn3o+zoi3yXppORp i/oSGzFYhrnN6wLY0deWFZQN X-Google-Smtp-Source: ABdhPJwdITITDox4GcVh6xb24molA1ZfNb1cR2YE1+P++Zm/LjSddQ/IITvYLY3uFTL3mFwiOs6XyA== X-Received: by 2002:a0c:f946:: with SMTP id i6mr6063551qvo.40.1614893393105; Thu, 04 Mar 2021 13:29:53 -0800 (PST) Received: from localhost ([151.203.60.33]) by smtp.gmail.com with ESMTPSA id z65sm606102qtd.15.2021.03.04.13.29.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 Mar 2021 13:29:52 -0800 (PST) Subject: [PATCH] cipso,calipso: resolve a number of problems with the DOI refcounts From: Paul Moore To: netdev@vger.kernel.org Cc: linux-security-module@vger.kernel.org, selinux@vger.kernel.org, Dmitry Vyukov Date: Thu, 04 Mar 2021 16:29:51 -0500 Message-ID: <161489339182.63157.2775083878484465675.stgit@olly> User-Agent: StGit/1.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org The current CIPSO and CALIPSO refcounting scheme for the DOI definitions is a bit flawed in that we: 1. Don't correctly match gets/puts in netlbl_cipsov4_list(). 2. Decrement the refcount on each attempt to remove the DOI from the DOI list, only removing it from the list once the refcount drops to zero. This patch fixes these problems by adding the missing "puts" to netlbl_cipsov4_list() and introduces a more conventional, i.e. not-buggy, refcounting mechanism to the DOI definitions. Upon the addition of a DOI to the DOI list, it is initialized with a refcount of one, removing a DOI from the list removes it from the list and drops the refcount by one; "gets" and "puts" behave as expected with respect to refcounts, increasing and decreasing the DOI's refcount by one. Fixes: b1edeb102397 ("netlabel: Replace protocol/NetLabel linking with refrerence counts") Fixes: d7cce01504a0 ("netlabel: Add support for removing a CALIPSO DOI.") Reported-by: syzbot+9ec037722d2603a9f52e@syzkaller.appspotmail.com Signed-off-by: Paul Moore --- net/ipv4/cipso_ipv4.c | 11 +---------- net/ipv6/calipso.c | 14 +++++--------- net/netlabel/netlabel_cipso_v4.c | 3 +++ 3 files changed, 9 insertions(+), 19 deletions(-) diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index 471d33a0d095..be09c7669a79 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -519,16 +519,10 @@ int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info) ret_val = -ENOENT; goto doi_remove_return; } - if (!refcount_dec_and_test(&doi_def->refcount)) { - spin_unlock(&cipso_v4_doi_list_lock); - ret_val = -EBUSY; - goto doi_remove_return; - } list_del_rcu(&doi_def->list); spin_unlock(&cipso_v4_doi_list_lock); - cipso_v4_cache_invalidate(); - call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu); + cipso_v4_doi_putdef(doi_def); ret_val = 0; doi_remove_return: @@ -585,9 +579,6 @@ void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def) if (!refcount_dec_and_test(&doi_def->refcount)) return; - spin_lock(&cipso_v4_doi_list_lock); - list_del_rcu(&doi_def->list); - spin_unlock(&cipso_v4_doi_list_lock); cipso_v4_cache_invalidate(); call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu); diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c index 51184a70ac7e..1578ed9e97d8 100644 --- a/net/ipv6/calipso.c +++ b/net/ipv6/calipso.c @@ -83,6 +83,9 @@ struct calipso_map_cache_entry { static struct calipso_map_cache_bkt *calipso_cache; +static void calipso_cache_invalidate(void); +static void calipso_doi_putdef(struct calipso_doi *doi_def); + /* Label Mapping Cache Functions */ @@ -444,15 +447,10 @@ static int calipso_doi_remove(u32 doi, struct netlbl_audit *audit_info) ret_val = -ENOENT; goto doi_remove_return; } - if (!refcount_dec_and_test(&doi_def->refcount)) { - spin_unlock(&calipso_doi_list_lock); - ret_val = -EBUSY; - goto doi_remove_return; - } list_del_rcu(&doi_def->list); spin_unlock(&calipso_doi_list_lock); - call_rcu(&doi_def->rcu, calipso_doi_free_rcu); + calipso_doi_putdef(doi_def); ret_val = 0; doi_remove_return: @@ -508,10 +506,8 @@ static void calipso_doi_putdef(struct calipso_doi *doi_def) if (!refcount_dec_and_test(&doi_def->refcount)) return; - spin_lock(&calipso_doi_list_lock); - list_del_rcu(&doi_def->list); - spin_unlock(&calipso_doi_list_lock); + calipso_cache_invalidate(); call_rcu(&doi_def->rcu, calipso_doi_free_rcu); } diff --git a/net/netlabel/netlabel_cipso_v4.c b/net/netlabel/netlabel_cipso_v4.c index 726dda95934c..4f50a64315cf 100644 --- a/net/netlabel/netlabel_cipso_v4.c +++ b/net/netlabel/netlabel_cipso_v4.c @@ -575,6 +575,7 @@ static int netlbl_cipsov4_list(struct sk_buff *skb, struct genl_info *info) break; } + cipso_v4_doi_putdef(doi_def); rcu_read_unlock(); genlmsg_end(ans_skb, data); @@ -583,12 +584,14 @@ static int netlbl_cipsov4_list(struct sk_buff *skb, struct genl_info *info) list_retry: /* XXX - this limit is a guesstimate */ if (nlsze_mult < 4) { + cipso_v4_doi_putdef(doi_def); rcu_read_unlock(); kfree_skb(ans_skb); nlsze_mult *= 2; goto list_start; } list_failure_lock: + cipso_v4_doi_putdef(doi_def); rcu_read_unlock(); list_failure: kfree_skb(ans_skb);