From patchwork Mon Apr 12 22:30:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 419825 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 922B2C43460 for ; Mon, 12 Apr 2021 22:31:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77C926135C for ; Mon, 12 Apr 2021 22:31:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343780AbhDLWb3 (ORCPT ); Mon, 12 Apr 2021 18:31:29 -0400 Received: from mail.netfilter.org ([217.70.188.207]:50474 "EHLO mail.netfilter.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343746AbhDLWb1 (ORCPT ); Mon, 12 Apr 2021 18:31:27 -0400 Received: from localhost.localdomain (unknown [90.77.255.23]) by mail.netfilter.org (Postfix) with ESMTPSA id E18B663E63; Tue, 13 Apr 2021 00:30:42 +0200 (CEST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org Subject: [PATCH net 3/7] netfilter: nft_limit: avoid possible divide error in nft_limit_init Date: Tue, 13 Apr 2021 00:30:55 +0200 Message-Id: <20210412223059.20841-4-pablo@netfilter.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210412223059.20841-1-pablo@netfilter.org> References: <20210412223059.20841-1-pablo@netfilter.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Eric Dumazet div_u64() divides u64 by u32. nft_limit_init() wants to divide u64 by u64, use the appropriate math function (div64_u64) divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8390 Comm: syz-executor188 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:div_u64_rem include/linux/math64.h:28 [inline] RIP: 0010:div_u64 include/linux/math64.h:127 [inline] RIP: 0010:nft_limit_init+0x2a2/0x5e0 net/netfilter/nft_limit.c:85 Code: ef 4c 01 eb 41 0f 92 c7 48 89 de e8 38 a5 22 fa 4d 85 ff 0f 85 97 02 00 00 e8 ea 9e 22 fa 4c 0f af f3 45 89 ed 31 d2 4c 89 f0 <49> f7 f5 49 89 c6 e8 d3 9e 22 fa 48 8d 7d 48 48 b8 00 00 00 00 00 RSP: 0018:ffffc90009447198 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000200000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff875152e6 RDI: 0000000000000003 RBP: ffff888020f80908 R08: 0000200000000000 R09: 0000000000000000 R10: ffffffff875152d8 R11: 0000000000000000 R12: ffffc90009447270 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 000000000097a300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200001c4 CR3: 0000000026a52000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: nf_tables_newexpr net/netfilter/nf_tables_api.c:2675 [inline] nft_expr_init+0x145/0x2d0 net/netfilter/nf_tables_api.c:2713 nft_set_elem_expr_alloc+0x27/0x280 net/netfilter/nf_tables_api.c:5160 nf_tables_newset+0x1997/0x3150 net/netfilter/nf_tables_api.c:4321 nfnetlink_rcv_batch+0x85a/0x21b0 net/netfilter/nfnetlink.c:456 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:580 [inline] nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:598 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:674 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes: c26844eda9d4 ("netfilter: nf_tables: Fix nft limit burst handling") Fixes: 3e0f64b7dd31 ("netfilter: nft_limit: fix packet ratelimiting") Signed-off-by: Eric Dumazet Diagnosed-by: Luigi Rizzo Reported-by: syzbot Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_limit.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nft_limit.c b/net/netfilter/nft_limit.c index 0e2c315c3b5e..82ec27bdf941 100644 --- a/net/netfilter/nft_limit.c +++ b/net/netfilter/nft_limit.c @@ -76,13 +76,13 @@ static int nft_limit_init(struct nft_limit *limit, return -EOVERFLOW; if (pkts) { - tokens = div_u64(limit->nsecs, limit->rate) * limit->burst; + tokens = div64_u64(limit->nsecs, limit->rate) * limit->burst; } else { /* The token bucket size limits the number of tokens can be * accumulated. tokens_max specifies the bucket size. * tokens_max = unit * (rate + burst) / rate. */ - tokens = div_u64(limit->nsecs * (limit->rate + limit->burst), + tokens = div64_u64(limit->nsecs * (limit->rate + limit->burst), limit->rate); }