From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZpCFQ3I1IZKx6S5io2nZndueQZOnnltX4jcaj6tDBVMEGBYUSFJZQ3Q//Fl/szokkg7oXqL ARC-Seal: i=1; a=rsa-sha256; t=1526937506; cv=none; d=google.com; s=arc-20160816; b=jmAxZ8eu63f3sN3de/ZyU/JdEbFNyGjhji5bBYsJbO9qyCxsNiqhR0p1MkrS6hRKLP 3/bM1YSHcHkj2O0sQXJb3m7TiPAXTmd199P4YfzdljCgNnb8nZEurHd7hy7yw5A4kjnA +TM/izLqVG/SFXDsLl+DhydkkzBpttx8ZYHG0Ua37My6MSrjvrBrjRX7vL6Jm12DvvQl IfOtZ04a1Ucl3hWPWaZJDEXoREzh0DgKzC1qjlMNcBGLU2rIa6ToVlm+xGJzPWPd4+B6 tXu8lsn5uWqR+pRvqXez1R9FwHTZJpig4RmWbby3ge/SIxHyvA3sWm7TZ5dT58mqJ7ot ok8A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:arc-authentication-results; bh=BPjLCp+KEbytnAPW2sJYV3JpAt7pq6TV1wwKPOoTbjQ=; b=FHsA76htiJJKJ60J4INq0jKHjXNNI0y6JFh1WLIdU671KP/3weY7bez2PtLg0T08PV 1Q9oeO6uB/Y3towyyB1WqcWkM2238Arqcxwg1W3Cx+bZoxUQ27JWkEihBAGZvEVnqa00 0/acbSNtIhFErdzlLVyzEr6wVqINc1MJ2EQxrZ9yswlsJLVS4xdx29YWeV35BpW3Yl3/ gWvcNxUBjV0t7QyjCYnCqMq87ydofpXxdSXBebt1o5CP4L51k2lmHoTdKYbtRwXwQmus +sLnYSHGFVqNq3JP2UANwSsV+m6QDyfWe4z+LHx7Kw60VlhZRIc7M0+ic1HqymVDHR0G i69Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=VKSXUXh1; spf=pass (google.com: domain of srs0=nia/=ii=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=nia/=II=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=VKSXUXh1; spf=pass (google.com: domain of srs0=nia/=ii=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=nia/=II=linuxfoundation.org=gregkh@kernel.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Florian Westphal , Pablo Neira Ayuso Subject: [PATCH 4.14 19/95] netfilter: nf_tables: cant fail after linking rule into active rule list Date: Mon, 21 May 2018 23:11:09 +0200 Message-Id: <20180521210451.704026996@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180521210447.219380974@linuxfoundation.org> References: <20180521210447.219380974@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1601109783674177294?= X-GMAIL-MSGID: =?utf-8?q?1601110022528555118?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal commit 569ccae68b38654f04b6842b034aa33857f605fe upstream. rules in nftables a free'd using kfree, but protected by rcu, i.e. we must wait for a grace period to elapse. Normal removal patch does this, but nf_tables_newrule() doesn't obey this rule during error handling. It calls nft_trans_rule_add() *after* linking rule, and, if that fails to allocate memory, it unlinks the rule and then kfree() it -- this is unsafe. Switch order -- first add rule to transaction list, THEN link it to public list. Note: nft_trans_rule_add() uses GFP_KERNEL; it will not fail so this is not a problem in practice (spotted only during code review). Fixes: 0628b123c96d12 ("netfilter: nfnetlink: add batch support and use it from nf_tables") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_tables_api.c | 59 ++++++++++++++++++++++-------------------- 1 file changed, 32 insertions(+), 27 deletions(-) --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2344,41 +2344,46 @@ static int nf_tables_newrule(struct net } if (nlh->nlmsg_flags & NLM_F_REPLACE) { - if (nft_is_active_next(net, old_rule)) { - trans = nft_trans_rule_add(&ctx, NFT_MSG_DELRULE, - old_rule); - if (trans == NULL) { - err = -ENOMEM; - goto err2; - } - nft_deactivate_next(net, old_rule); - chain->use--; - list_add_tail_rcu(&rule->list, &old_rule->list); - } else { + if (!nft_is_active_next(net, old_rule)) { err = -ENOENT; goto err2; } - } else if (nlh->nlmsg_flags & NLM_F_APPEND) - if (old_rule) - list_add_rcu(&rule->list, &old_rule->list); - else - list_add_tail_rcu(&rule->list, &chain->rules); - else { - if (old_rule) - list_add_tail_rcu(&rule->list, &old_rule->list); - else - list_add_rcu(&rule->list, &chain->rules); - } + trans = nft_trans_rule_add(&ctx, NFT_MSG_DELRULE, + old_rule); + if (trans == NULL) { + err = -ENOMEM; + goto err2; + } + nft_deactivate_next(net, old_rule); + chain->use--; + + if (nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule) == NULL) { + err = -ENOMEM; + goto err2; + } - if (nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule) == NULL) { - err = -ENOMEM; - goto err3; + list_add_tail_rcu(&rule->list, &old_rule->list); + } else { + if (nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule) == NULL) { + err = -ENOMEM; + goto err2; + } + + if (nlh->nlmsg_flags & NLM_F_APPEND) { + if (old_rule) + list_add_rcu(&rule->list, &old_rule->list); + else + list_add_tail_rcu(&rule->list, &chain->rules); + } else { + if (old_rule) + list_add_tail_rcu(&rule->list, &old_rule->list); + else + list_add_rcu(&rule->list, &chain->rules); + } } chain->use++; return 0; -err3: - list_del_rcu(&rule->list); err2: nf_tables_rule_destroy(&ctx, rule); err1: