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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E3EAC433FE for ; Tue, 22 Nov 2022 17:56:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234483AbiKVR4L (ORCPT ); Tue, 22 Nov 2022 12:56:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234526AbiKVRzq (ORCPT ); Tue, 22 Nov 2022 12:55:46 -0500 Received: from mail-yw1-x112c.google.com (mail-yw1-x112c.google.com [IPv6:2607:f8b0:4864:20::112c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A848DB5; Tue, 22 Nov 2022 09:54:37 -0800 (PST) Received: by mail-yw1-x112c.google.com with SMTP id 00721157ae682-3a4c2c83300so55977427b3.13; Tue, 22 Nov 2022 09:54:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=L0rPPoMf/BQcnP7OVRdbz7eh/i+6Gf4OOaHX2I41UhU=; b=d5VW+1b1VGIj13TRqpfUbm9lLtaM1CtTAtbQ1RHvN0H9yd6uo1BpMvacToZcZFyzx3 mQVjzGPGlrTVWDfBiXXxeBlRrQDYIEtzyJAcj5x6UXF8wq2+nIGL0TgNkMkYM/6ZBhLE 0c/0eFFu6uFJpNaehRs/89T3C+109cH6rH8OxLRyTCErkOB6+VrUOnrH8KdiyuIFrN2r z6v7qGm09vuHS/rFVDHOcj7vw+7NRYDPWDgr2i3Ut6Uzk4/oDZSxLGN5Wt/RE/fr2blY x1IZLZ3mM6pzIHyMuyLn2InX6z3+9vPyLUZBGEB6V47GOZ49n73GSWqTPca53SHMvh9O CcSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=L0rPPoMf/BQcnP7OVRdbz7eh/i+6Gf4OOaHX2I41UhU=; b=SSKBPtb11B0AhJQOr+no/rGQiQ6uuaro/zFDCjYMbE4BFAckmjqKPOdu0xNHK1PxMq mlm0opSBVYgRcjgWC7gjiX0ZPN+uCo2HCPtKUkK+wiS1XeZg0DmQc9oTzpji1NIiJhVt Rz2xzN/6opqbzquwa+ghwReukOACY7N/Hd2ASFK5+hfOyo+0BB4bC/RIIp5/Pu+Ri1Iw f6uXMgxak0l9/E/lXe2kFK/mG/5bfuk3RuAfRvCi9Zu8kwc7Fe5K1qMBr/CqNKI+Rtti 4M3kEb6Jnstu7+JcHEkX4QDvNQI5f1U+cnQdwmgRoYW3g4CTB+P1MIVKg3GvNguxCVwb Ofkg== X-Gm-Message-State: ANoB5pl7t8+0oULQVEpGheIjyfFDtjI4POQKJnbbzMZSs6J/mAQUKJOz ai/o2uPTVcNLOBijQVp5gOZ4E420jdXYvb0byII= X-Google-Smtp-Source: AA0mqf7+udcH8F5ou6EBnqpzxPoJ7Sn8opE9LMmn0RU+R8gjos9Cxgw6UcypmHl1cUNGp6GSPUPn1vr95GiFH8GNwR0= X-Received: by 2002:a81:9145:0:b0:36c:ada0:8ae8 with SMTP id i66-20020a819145000000b0036cada08ae8mr4625148ywg.513.1669139676417; Tue, 22 Nov 2022 09:54:36 -0800 (PST) MIME-Version: 1.0 References: <20221122005050.56912-1-kuniyu@amazon.com> In-Reply-To: <20221122005050.56912-1-kuniyu@amazon.com> From: Joanne Koong Date: Tue, 22 Nov 2022 09:54:24 -0800 Message-ID: Subject: Re: [PATCH v4 net 4/4] dccp/tcp: Fixup bhash2 bucket when connect() fails. To: Kuniyuki Iwashima Cc: acme@mandriva.com, davem@davemloft.net, dccp@vger.kernel.org, dsahern@kernel.org, edumazet@google.com, kuba@kernel.org, kuni1840@gmail.com, martin.lau@kernel.org, mathew.j.martineau@linux.intel.com, netdev@vger.kernel.org, pabeni@redhat.com, pengfei.xu@intel.com, stephen@networkplumber.org, syzkaller@googlegroups.com, william.xuanziyang@huawei.com, yoshfuji@linux-ipv6.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Nov 21, 2022 at 4:51 PM Kuniyuki Iwashima wrote: > > From: Joanne Koong > Date: Mon, 21 Nov 2022 15:41:43 -0800 > > On Fri, Nov 18, 2022 at 5:51 PM Kuniyuki Iwashima wrote: > > > > > > If a socket bound to a wildcard address fails to connect(), we > > > only reset saddr and keep the port. Then, we have to fix up the > > > bhash2 bucket; otherwise, the bucket has an inconsistent address > > > in the list. > > > > > > Also, listen() for such a socket will fire the WARN_ON() in > > > inet_csk_get_port(). [0] > > > > > > Note that when a system runs out of memory, we give up fixing the > > > bucket and unlink sk from bhash and bhash2 by inet_put_port(). > > > > > > [0]: > > > WARNING: CPU: 0 PID: 207 at net/ipv4/inet_connection_sock.c:548 inet_csk_get_port (net/ipv4/inet_connection_sock.c:548 (discriminator 1)) > > > Modules linked in: > > > CPU: 0 PID: 207 Comm: bhash2_prev_rep Not tainted 6.1.0-rc3-00799-gc8421681c845 #63 > > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.amzn2022.0.1 04/01/2014 > > > RIP: 0010:inet_csk_get_port (net/ipv4/inet_connection_sock.c:548 (discriminator 1)) > > > Code: 74 a7 eb 93 48 8b 54 24 18 0f b7 cb 4c 89 e6 4c 89 ff e8 48 b2 ff ff 49 8b 87 18 04 00 00 e9 32 ff ff ff 0f 0b e9 34 ff ff ff <0f> 0b e9 42 ff ff ff 41 8b 7f 50 41 8b 4f 54 89 fe 81 f6 00 00 ff > > > RSP: 0018:ffffc900003d7e50 EFLAGS: 00010202 > > > RAX: ffff8881047fb500 RBX: 0000000000004e20 RCX: 0000000000000000 > > > RDX: 000000000000000a RSI: 00000000fffffe00 RDI: 00000000ffffffff > > > RBP: ffffffff8324dc00 R08: 0000000000000001 R09: 0000000000000001 > > > R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 > > > R13: 0000000000000001 R14: 0000000000004e20 R15: ffff8881054e1280 > > > FS: 00007f8ac04dc740(0000) GS:ffff88842fc00000(0000) knlGS:0000000000000000 > > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > CR2: 0000000020001540 CR3: 00000001055fa003 CR4: 0000000000770ef0 > > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > PKRU: 55555554 > > > Call Trace: > > > > > > inet_csk_listen_start (net/ipv4/inet_connection_sock.c:1205) > > > inet_listen (net/ipv4/af_inet.c:228) > > > __sys_listen (net/socket.c:1810) > > > __x64_sys_listen (net/socket.c:1819 net/socket.c:1817 net/socket.c:1817) > > > do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) > > > entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) > > > RIP: 0033:0x7f8ac051de5d > > > Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 93 af 1b 00 f7 d8 64 89 01 48 > > > RSP: 002b:00007ffc1c177248 EFLAGS: 00000206 ORIG_RAX: 0000000000000032 > > > RAX: ffffffffffffffda RBX: 0000000020001550 RCX: 00007f8ac051de5d > > > RDX: ffffffffffffff80 RSI: 0000000000000000 RDI: 0000000000000004 > > > RBP: 00007ffc1c177270 R08: 0000000000000018 R09: 0000000000000007 > > > R10: 0000000020001540 R11: 0000000000000206 R12: 00007ffc1c177388 > > > R13: 0000000000401169 R14: 0000000000403e18 R15: 00007f8ac0723000 > > > > > > > > > Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address") > > > Reported-by: syzbot > > > Reported-by: Mat Martineau > > > Signed-off-by: Kuniyuki Iwashima > > > > Acked-by: Joanne Koong > > Thanks for all your help! > > > > > --- > > > include/net/inet_hashtables.h | 1 + > > > net/dccp/ipv4.c | 3 +-- > > > net/dccp/ipv6.c | 3 +-- > > > net/dccp/proto.c | 3 +-- > > > net/ipv4/inet_hashtables.c | 38 +++++++++++++++++++++++++++++++---- > > > net/ipv4/tcp.c | 3 +-- > > > net/ipv4/tcp_ipv4.c | 3 +-- > > > net/ipv6/tcp_ipv6.c | 3 +-- > > > 8 files changed, 41 insertions(+), 16 deletions(-) > > > > > > diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h > > > index ba06e8b52264..69174093078f 100644 > > > --- a/include/net/inet_hashtables.h > > > +++ b/include/net/inet_hashtables.h > > > @@ -282,6 +282,7 @@ inet_bhash2_addr_any_hashbucket(const struct sock *sk, const struct net *net, in > > > * rcv_saddr field should already have been updated when this is called. > > > */ > > > int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family); > > > +void inet_bhash2_reset_saddr(struct sock *sk); > > > > > > void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb, > > > struct inet_bind2_bucket *tb2, unsigned short port); > > > diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c > > > index 95e376e3b911..b780827f5e0a 100644 > > > --- a/net/dccp/ipv4.c > > > +++ b/net/dccp/ipv4.c > > > @@ -143,8 +143,7 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) > > > * This unhashes the socket and releases the local port, if necessary. > > > */ > > > dccp_set_state(sk, DCCP_CLOSED); > > > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > > > - inet_reset_saddr(sk); > > > + inet_bhash2_reset_saddr(sk); > > > ip_rt_put(rt); > > > sk->sk_route_caps = 0; > > > inet->inet_dport = 0; > > > diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c > > > index 94c101ed57a9..602f3432d80b 100644 > > > --- a/net/dccp/ipv6.c > > > +++ b/net/dccp/ipv6.c > > > @@ -970,8 +970,7 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr, > > > > > > late_failure: > > > dccp_set_state(sk, DCCP_CLOSED); > > > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > > > - inet_reset_saddr(sk); > > > + inet_bhash2_reset_saddr(sk); > > > __sk_dst_reset(sk); > > > failure: > > > inet->inet_dport = 0; > > > diff --git a/net/dccp/proto.c b/net/dccp/proto.c > > > index c548ca3e9b0e..85e35c5e8890 100644 > > > --- a/net/dccp/proto.c > > > +++ b/net/dccp/proto.c > > > @@ -279,8 +279,7 @@ int dccp_disconnect(struct sock *sk, int flags) > > > > > > inet->inet_dport = 0; > > > > > > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > > > - inet_reset_saddr(sk); > > > + inet_bhash2_reset_saddr(sk); > > > > > > sk->sk_shutdown = 0; > > > sock_reset_flag(sk, SOCK_DONE); > > > diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c > > > index 18ef370af113..3cec471a2cd2 100644 > > > --- a/net/ipv4/inet_hashtables.c > > > +++ b/net/ipv4/inet_hashtables.c > > > @@ -871,7 +871,7 @@ static void inet_update_saddr(struct sock *sk, void *saddr, int family) > > > #endif > > > } > > > > > > -int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > > > +static int __inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family, bool reset) > > > { > > > struct inet_hashinfo *hinfo = tcp_or_dccp_get_hashinfo(sk); > > > struct inet_bind_hashbucket *head, *head2; > > > @@ -883,7 +883,11 @@ int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > > > > > > if (!inet_csk(sk)->icsk_bind2_hash) { > > > /* Not bind()ed before. */ > > > - inet_update_saddr(sk, saddr, family); > > > + if (reset) > > > + inet_reset_saddr(sk); > > > + else > > > + inet_update_saddr(sk, saddr, family); > > > + > > > return 0; > > > } > > > > > > @@ -892,8 +896,19 @@ int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > > > * allocation fails. > > > */ > > > new_tb2 = kmem_cache_alloc(hinfo->bind2_bucket_cachep, GFP_ATOMIC); > > > - if (!new_tb2) > > > + if (!new_tb2) { > > > + if (reset) { > > > + /* The (INADDR_ANY, port) bucket might have already > > > + * been freed, then we cannot fixup icsk_bind2_hash, > > > + * so we give up and unlink sk from bhash/bhash2 not > > > + * to leave inconsistency in bhash2. > > > + */ > > > + inet_put_port(sk); > > > + inet_reset_saddr(sk); > > > + } > > > > nit: I think this is better placed in the dccp/tcp_ipv4/6 layer, to > > make it clear / more obvious that the sk gets unbinded in this edge > > case. > > But it duplicates 2 calls (and a comment) across 6 places. > > or we can move it to inet_bhash2_reset_saddr() like > > void inet_bhash2_reset_saddr(struct sock *sk) > { > if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK) && > __inet_bhash2_update_saddr(sk, NULL, 0, true) { > inet_put_port(sk); > inet_reset_saddr(sk); > } > } > EXPORT_SYMBOL_GPL(inet_bhash2_reset_saddr); > > I'm fine with whichever, which do you like ? > > Or we can go as is and post a follow-up. > I'm fine with whichever too. I think it being in inet_bhash2_reset_saddr() would be clearer than it being within __inet_bhash2_update_saddr(). Thanks for your work on this! > > > > > > + > > > return -ENOMEM; > > > + } > > > > > > bhash = inet_bhashfn(net, port, hinfo->bhash_size); > > > head = &hinfo->bhash[bhash]; > > > @@ -909,7 +924,10 @@ int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > > > inet_bind2_bucket_destroy(hinfo->bind2_bucket_cachep, inet_csk(sk)->icsk_bind2_hash); > > > spin_unlock(&head2->lock); > > > > > > - inet_update_saddr(sk, saddr, family); > > > + if (reset) > > > + inet_reset_saddr(sk); > > > + else > > > + inet_update_saddr(sk, saddr, family); > > > > > > head2 = inet_bhashfn_portaddr(hinfo, sk, net, port); > > > > > > @@ -930,8 +948,20 @@ int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > > > > > > return 0; > > > } > > > + > > > +int inet_bhash2_update_saddr(struct sock *sk, void *saddr, int family) > > > +{ > > > + return __inet_bhash2_update_saddr(sk, saddr, family, false); > > > +} > > > EXPORT_SYMBOL_GPL(inet_bhash2_update_saddr); > > > > > > +void inet_bhash2_reset_saddr(struct sock *sk) > > > +{ > > > + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > > > + __inet_bhash2_update_saddr(sk, NULL, 0, true); > > > +} > > > +EXPORT_SYMBOL_GPL(inet_bhash2_reset_saddr); > > > > > + > > > /* RFC 6056 3.3.4. Algorithm 4: Double-Hash Port Selection Algorithm > > > * Note that we use 32bit integers (vs RFC 'short integers') > > > * because 2^16 is not a multiple of num_ephemeral and this > > > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > > > index 54836a6b81d6..4f2205756cfe 100644 > > > --- a/net/ipv4/tcp.c > > > +++ b/net/ipv4/tcp.c > > > @@ -3114,8 +3114,7 @@ int tcp_disconnect(struct sock *sk, int flags) > > > > > > inet->inet_dport = 0; > > > > > > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > > > - inet_reset_saddr(sk); > > > + inet_bhash2_reset_saddr(sk); > > > > > > sk->sk_shutdown = 0; > > > sock_reset_flag(sk, SOCK_DONE); > > > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > > > index 23dd7e9df2d5..da46357f501b 100644 > > > --- a/net/ipv4/tcp_ipv4.c > > > +++ b/net/ipv4/tcp_ipv4.c > > > @@ -331,8 +331,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) > > > * if necessary. > > > */ > > > tcp_set_state(sk, TCP_CLOSE); > > > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > > > - inet_reset_saddr(sk); > > > + inet_bhash2_reset_saddr(sk); > > > ip_rt_put(rt); > > > sk->sk_route_caps = 0; > > > inet->inet_dport = 0; > > > diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c > > > index 2f3ca3190d26..f0548dbcabd2 100644 > > > --- a/net/ipv6/tcp_ipv6.c > > > +++ b/net/ipv6/tcp_ipv6.c > > > @@ -346,8 +346,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, > > > > > > late_failure: > > > tcp_set_state(sk, TCP_CLOSE); > > > - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) > > > - inet_reset_saddr(sk); > > > + inet_bhash2_reset_saddr(sk); > > > failure: > > > inet->inet_dport = 0; > > > sk->sk_route_caps = 0; > > > -- > > > 2.30.2