From mboxrd@z Thu Jan 1 00:00:00 1970 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 smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AE34AC43334 for ; Sat, 9 Jul 2022 02:47:21 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 2936560675; Sat, 9 Jul 2022 02:47:21 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 2936560675 Authentication-Results: smtp3.osuosl.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=JykCDruT X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id VokBuoSw-Il7; Sat, 9 Jul 2022 02:47:20 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp3.osuosl.org (Postfix) with ESMTPS id C70C2606EC; Sat, 9 Jul 2022 02:47:19 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org C70C2606EC Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9380AC0033; Sat, 9 Jul 2022 02:47:19 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id DE933C002D for ; Sat, 9 Jul 2022 02:47:18 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 11A54400F3 for ; Sat, 9 Jul 2022 02:47:18 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 11A54400F3 Authentication-Results: smtp2.osuosl.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=JykCDruT X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Bh_ZLU6lJy4M for ; Sat, 9 Jul 2022 02:47:17 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 3CE2F400F1 Received: from mail-oa1-x33.google.com (mail-oa1-x33.google.com [IPv6:2001:4860:4864:20::33]) by smtp2.osuosl.org (Postfix) with ESMTPS id 3CE2F400F1 for ; Sat, 9 Jul 2022 02:47:17 +0000 (UTC) Received: by mail-oa1-x33.google.com with SMTP id 586e51a60fabf-10bf634bc50so875306fac.3 for ; Fri, 08 Jul 2022 19:47:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=6BGKZlQ2XgPXargm2Wo7BrmlFidyoAhj3y0XxGiXJm0=; b=JykCDruTogaWu6LLxNnu8Hd8UnhoJw4HRRvDIpLjJ3ArGe9cb7eNVrYGXxOlZhf9HH pNklBJZxZ9Gy29spJTJqCHrIDxvRTBr1RSvwrqhV9UE9qvzQsf6Z4GN885ZZHNiRFmmA fqLPZ4oaPvYSZINiq45OiSReXqi+isfQ/BkcqEqqNnRaFEqMj/H2x5c/dnWhmUS9UCjr XxUmLujFcDkNylO/H6/dwgjdP2R3DweSb3MShtbRT6m4DfROYxmJy0w9YxTlnic5PNKc C8UNMkn6QSIyAaxy9mHISrYyUojjBYxmmPBqNeMbgBpD/+Bbux/0oH011IRwfZae8dPq J04Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=6BGKZlQ2XgPXargm2Wo7BrmlFidyoAhj3y0XxGiXJm0=; b=v3+otZlsLhh1wTHLHy8rnnIzqmgqcSogjWzApVMbraJV6BS7HNPOq5qvrG5JxHMxrr +Xw5G7I8Vq9jAHbCb8pDFqm3hogL6wUXodSZ+Z9NfJ4RjLXnnCABUCb8QlKVtlNG1fib oIK5W1aCfYb+/tYd9vfHSfAqToFxy4QRhVHH2BRMiOwNi4jB2RMuiSRXsL9rKoij8SPb V3PLdz44xZ0xCxzbUpp4iBHNPcAaosQa6o9honj9eOl6mtXDdiuBoHSNKxTZM+IP6byb PdSgkVDtsxumUy8vXdNKXGw759upqWcNMXth/tlyharC9Baz2BC3g5SkRCLWBsnAtInP o3ig== X-Gm-Message-State: AJIora9b0bFZ3r75/zbf1rlL5HcjaiDqhhrWygriZ52uvXh8f7nmuNIa nmHlk2RSEoj/ZTBWV1zwga4= X-Google-Smtp-Source: AGRyM1vEOmXQ0e6DzN+O8R9g1l8g+u86gRu6KOjY6pNieru/kNk84RuiD7FmFu2uEYfiHCgH1y6KvA== X-Received: by 2002:a05:6870:c0ce:b0:10c:4d83:8e15 with SMTP id e14-20020a056870c0ce00b0010c4d838e15mr1624440oad.137.1657334836236; Fri, 08 Jul 2022 19:47:16 -0700 (PDT) Received: from ubuntu.lan ([136.175.179.221]) by smtp.gmail.com with ESMTPSA id u65-20020acaab44000000b0032eb81e352asm274880oie.38.2022.07.08.19.47.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Jul 2022 19:47:15 -0700 (PDT) From: Hawkins Jiawei To: syzbot+5f26f85569bd179c18ce@syzkaller.appspotmail.com Subject: [PATCH] smc: fix refcount bug in sk_psock_get (2) Date: Sat, 9 Jul 2022 10:46:59 +0800 Message-Id: <20220709024659.6671-1-yin31149@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <00000000000026328205e08cdbeb@google.com> References: <00000000000026328205e08cdbeb@google.com> MIME-Version: 1.0 Cc: songliubraving@fb.com, ast@kernel.org, edumazet@google.com, daniel@iogearbox.net, davem@davemloft.net, borisp@nvidia.com, paskripkin@gmail.com, john.fastabend@gmail.com, andrii@kernel.org, yhs@fb.com, pabeni@redhat.com, linux-kernel-mentees@lists.linuxfoundation.org, syzkaller-bugs@googlegroups.com, kpsingh@kernel.org, kuba@kernel.org, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, dsahern@kernel.org, linux-kernel@vger.kernel.org, kgraul@linux.ibm.com, guwen@linux.alibaba.com, bpf@vger.kernel.org, kafai@fb.com X-BeenThere: linux-kernel-mentees@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-kernel-mentees-bounces@lists.linuxfoundation.org Sender: "Linux-kernel-mentees" From: hawk <18801353760@163.com> Syzkaller reportes refcount bug as follows: ------------[ cut here ]------------ refcount_t: saturated; leaking memory. WARNING: CPU: 1 PID: 3605 at lib/refcount.c:19 refcount_warn_saturate+0xf4/0x1e0 lib/refcount.c:19 Modules linked in: CPU: 1 PID: 3605 Comm: syz-executor208 Not tainted 5.18.0-syzkaller-03023-g7e062cda7d90 #0 ... Call Trace: __refcount_add_not_zero include/linux/refcount.h:163 [inline] __refcount_inc_not_zero include/linux/refcount.h:227 [inline] refcount_inc_not_zero include/linux/refcount.h:245 [inline] sk_psock_get+0x3bc/0x410 include/linux/skmsg.h:439 tls_data_ready+0x6d/0x1b0 net/tls/tls_sw.c:2091 tcp_data_ready+0x106/0x520 net/ipv4/tcp_input.c:4983 tcp_data_queue+0x25f2/0x4c90 net/ipv4/tcp_input.c:5057 tcp_rcv_state_process+0x1774/0x4e80 net/ipv4/tcp_input.c:6659 tcp_v4_do_rcv+0x339/0x980 net/ipv4/tcp_ipv4.c:1682 sk_backlog_rcv include/net/sock.h:1061 [inline] __release_sock+0x134/0x3b0 net/core/sock.c:2849 release_sock+0x54/0x1b0 net/core/sock.c:3404 inet_shutdown+0x1e0/0x430 net/ipv4/af_inet.c:909 __sys_shutdown_sock net/socket.c:2331 [inline] __sys_shutdown_sock net/socket.c:2325 [inline] __sys_shutdown+0xf1/0x1b0 net/socket.c:2343 __do_sys_shutdown net/socket.c:2351 [inline] __se_sys_shutdown net/socket.c:2349 [inline] __x64_sys_shutdown+0x50/0x70 net/socket.c:2349 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 syzbot is try to setup TLS on a SMC socket. During SMC fallback process in connect syscall, kernel will sets the smc->sk.sk_socket->file->private_data to smc->clcsock in smc_switch_to_fallback(), and set smc->clcsock->sk_user_data to origin smc in smc_fback_replace_callbacks(). When syzbot makes a setsockopt syscall, its argument sockfd actually points to smc->clcsock, which is not a smc_sock type, So it won't call smc_setsockopt() in setsockopt syscall, instead it will call do_tcp_setsockopt() to setup TLS, which bypasses the fixes 734942cc4ea6, its content is shown as below > diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c > index be3e80b3e27f1..5eff7cccceffc 100644 > --- a/net/smc/af_smc.c > +++ b/net/smc/af_smc.c > @@ -2161,6 +2161,9 @@ static int smc_setsockopt(struct socket *sock, > int level, int optname, > struct smc_sock *smc; > int val, rc; > > + if (level == SOL_TCP && optname == TCP_ULP) > + return -EOPNOTSUPP; > + > smc = smc_sk(sk); > > /* generic setsockopts reaching us here always apply to the > @@ -2185,7 +2188,6 @@ static int smc_setsockopt(struct socket *sock, > int level, int optname, > if (rc || smc->use_fallback) > goto out; > switch (optname) { > - case TCP_ULP: > case TCP_FASTOPEN: > case TCP_FASTOPEN_CONNECT: > case TCP_FASTOPEN_KEY: > -- Later, sk_psock_get() will treat the smc->clcsock->sk_user_data as sk_psock type, which triggers the refcnt warning. So Just disallow this setup in do_tcp_setsockopt() is OK, by checking whether sk_user_data points to a SMC socket. Reported-and-tested-by: syzbot+5f26f85569bd179c18ce@syzkaller.appspotmail.com Signed-off-by: hawk <18801353760@163.com> --- net/ipv4/tcp.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 9984d23a7f3e..a1e6cab2c748 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3395,10 +3395,23 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname, } case TCP_ULP: { char name[TCP_ULP_NAME_MAX]; + struct sock *smc_sock; if (optlen < 1) return -EINVAL; + /* SMC sk_user_data may be treated as psock, + * which triggers a refcnt warning. + */ + rcu_read_lock(); + smc_sock = rcu_dereference_sk_user_data(sk); + if (level == SOL_TCP && smc_sock && + smc_sock->__sk_common.skc_family == AF_SMC) { + rcu_read_unlock(); + return -EOPNOTSUPP; + } + rcu_read_unlock(); + val = strncpy_from_sockptr(name, optval, min_t(long, TCP_ULP_NAME_MAX - 1, optlen)); -- 2.25.1 _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees