From patchwork Thu Apr 20 03:17:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Ziyang Xuan (William)" X-Patchwork-Id: 13217791 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91D23C77B75 for ; Thu, 20 Apr 2023 03:17:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233682AbjDTDRb (ORCPT ); Wed, 19 Apr 2023 23:17:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233633AbjDTDR3 (ORCPT ); Wed, 19 Apr 2023 23:17:29 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AEB1F3AAF; Wed, 19 Apr 2023 20:17:27 -0700 (PDT) Received: from canpemm500006.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Q22r146Gnz8xCV; Thu, 20 Apr 2023 11:16:33 +0800 (CST) Received: from localhost.localdomain (10.175.104.82) by canpemm500006.china.huawei.com (7.192.105.130) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Thu, 20 Apr 2023 11:17:25 +0800 From: Ziyang Xuan To: , , , , , , , CC: Subject: [PATCH 5.4 1/5] udp: Call inet6_destroy_sock() in setsockopt(IPV6_ADDRFORM). Date: Thu, 20 Apr 2023 11:17:20 +0800 Message-ID: <9efc534e1c3038ea6c6e495a3cfde0eaf153a0e3.1681952308.git.william.xuanziyang@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-Originating-IP: [10.175.104.82] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To canpemm500006.china.huawei.com (7.192.105.130) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Kuniyuki Iwashima commit 21985f43376cee092702d6cb963ff97a9d2ede68 upstream. Commit 4b340ae20d0e ("IPv6: Complete IPV6_DONTFRAG support") forgot to add a change to free inet6_sk(sk)->rxpmtu while converting an IPv6 socket into IPv4 with IPV6_ADDRFORM. After conversion, sk_prot is changed to udp_prot and ->destroy() never cleans it up, resulting in a memory leak. This is due to the discrepancy between inet6_destroy_sock() and IPV6_ADDRFORM, so let's call inet6_destroy_sock() from IPV6_ADDRFORM to remove the difference. However, this is not enough for now because rxpmtu can be changed without lock_sock() after commit 03485f2adcde ("udpv6: Add lockless sendmsg() support"). We will fix this case in the following patch. Note we will rename inet6_destroy_sock() to inet6_cleanup_sock() and remove unnecessary inet6_destroy_sock() calls in sk_prot->destroy() in the future. Fixes: 4b340ae20d0e ("IPv6: Complete IPV6_DONTFRAG support") Signed-off-by: Kuniyuki Iwashima Signed-off-by: Jakub Kicinski Signed-off-by: Ziyang Xuan --- include/net/ipv6.h | 1 + net/ipv6/af_inet6.c | 6 ++++++ net/ipv6/ipv6_sockglue.c | 20 ++++++++------------ 3 files changed, 15 insertions(+), 12 deletions(-) diff --git a/include/net/ipv6.h b/include/net/ipv6.h index b59b3dae0f71..54f6308dab9a 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -1100,6 +1100,7 @@ void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info); void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu); +void inet6_cleanup_sock(struct sock *sk); int inet6_release(struct socket *sock); int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len); int inet6_getname(struct socket *sock, struct sockaddr *uaddr, diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 56f396ecc26b..f3f56c9085b1 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -498,6 +498,12 @@ void inet6_destroy_sock(struct sock *sk) } EXPORT_SYMBOL_GPL(inet6_destroy_sock); +void inet6_cleanup_sock(struct sock *sk) +{ + inet6_destroy_sock(sk); +} +EXPORT_SYMBOL_GPL(inet6_cleanup_sock); + /* * This does both peername and sockname. */ diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index 1d7fad8269e6..86c550d63543 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -176,9 +176,6 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, if (optlen < sizeof(int)) goto e_inval; if (val == PF_INET) { - struct ipv6_txoptions *opt; - struct sk_buff *pktopt; - if (sk->sk_type == SOCK_RAW) break; @@ -209,7 +206,6 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, break; } - fl6_free_socklist(sk); __ipv6_sock_mc_close(sk); __ipv6_sock_ac_close(sk); @@ -244,14 +240,14 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, sk->sk_socket->ops = &inet_dgram_ops; sk->sk_family = PF_INET; } - opt = xchg((__force struct ipv6_txoptions **)&np->opt, - NULL); - if (opt) { - atomic_sub(opt->tot_len, &sk->sk_omem_alloc); - txopt_put(opt); - } - pktopt = xchg(&np->pktoptions, NULL); - kfree_skb(pktopt); + + /* Disable all options not to allocate memory anymore, + * but there is still a race. See the lockless path + * in udpv6_sendmsg() and ipv6_local_rxpmtu(). + */ + np->rxopt.all = 0; + + inet6_cleanup_sock(sk); /* * ... and add it to the refcnt debug socks count