From patchwork Thu Feb 11 16:26:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 1439574 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.01.org (client-ip=2001:19d0:306:5::1; helo=ml01.01.org; envelope-from=mptcp-bounces@lists.01.org; receiver=) Received: from ml01.01.org (ml01.01.org [IPv6:2001:19d0:306:5::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4Dc27d2MFRz9sBy for ; Fri, 12 Feb 2021 03:26:20 +1100 (AEDT) Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 2787C100EA2B5; Thu, 11 Feb 2021 08:26:18 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2a0a:51c0:0:12e:520::1; helo=chamillionaire.breakpoint.cc; envelope-from=fw@breakpoint.cc; receiver= Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id C9C5F100EA92F for ; Thu, 11 Feb 2021 08:26:15 -0800 (PST) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1lAEnE-000476-S4; Thu, 11 Feb 2021 17:26:12 +0100 From: Florian Westphal To: Cc: Florian Westphal , Christoph Paasch , Paolo Abeni Date: Thu, 11 Feb 2021 17:26:07 +0100 Message-Id: <20210211162607.10780-1-fw@strlen.de> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Message-ID-Hash: TNQHDOWNJEVM3KKEJM45RLCO5KVYHONQ X-Message-ID-Hash: TNQHDOWNJEVM3KKEJM45RLCO5KVYHONQ X-MailFrom: fw@breakpoint.cc X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header X-Mailman-Version: 3.1.1 Precedence: list Subject: [MPTCP] [PATCH] mptcp: dispose initial struct socket when its subflow is closed List-Id: Discussions regarding MPTCP upstreaming Archived-At: <> List-Archive: <> List-Help: List-Post: List-Subscribe: List-Unsubscribe: Christoph Paasch reported following crash: dst_release underflow WARNING: CPU: 0 PID: 1319 at net/core/dst.c:175 dst_release+0xc1/0xd0 net/core/dst.c:175 CPU: 0 PID: 1319 Comm: syz-executor217 Not tainted 5.11.0-rc6af8e85128b4d0d24083c5cac646e891227052e0c #70 Call Trace: rt_cache_route+0x12e/0x140 net/ipv4/route.c:1503 rt_set_nexthop.constprop.0+0x1fc/0x590 net/ipv4/route.c:1612 __mkroute_output net/ipv4/route.c:2484 [inline] ... Problem is that worker leaves msk->subflow alone even when it happened to close the subflow ssk associated with it. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/157 Reported-by: Christoph Paasch Suggested-by: Paolo Abeni Signed-off-by: Florian Westphal --- net/mptcp/protocol.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index d49e0efbdd50..c30dff10ed9a 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2106,6 +2106,14 @@ static struct sock *mptcp_subflow_get_retrans(const struct mptcp_sock *msk) return backup; } +static void mptcp_dispose_initial_subflowg(struct mptcp_sock *msk) +{ + if (msk->subflow) { + iput(SOCK_INODE(msk->subflow)); + msk->subflow = NULL; + } +} + /* subflow sockets can be either outgoing (connect) or incoming * (accept). * @@ -2117,6 +2125,8 @@ static struct sock *mptcp_subflow_get_retrans(const struct mptcp_sock *msk) static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk, struct mptcp_subflow_context *subflow) { + struct mptcp_sock *msk = mptcp_sk(sk); + list_del(&subflow->node); lock_sock_nested(ssk, SINGLE_DEPTH_NESTING); @@ -2145,6 +2155,9 @@ static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk, release_sock(ssk); sock_put(ssk); + + if (msk->subflow && ssk == msk->subflow->sk) + mptcp_dispose_initial_subflowg(msk); } void mptcp_close_ssk(struct sock *sk, struct sock *ssk, @@ -2526,12 +2539,6 @@ static void __mptcp_destroy_sock(struct sock *sk) might_sleep(); - /* dispose the ancillatory tcp socket, if any */ - if (msk->subflow) { - iput(SOCK_INODE(msk->subflow)); - msk->subflow = NULL; - } - /* be sure to always acquire the join list lock, to sync vs * mptcp_finish_join(). */ @@ -2556,6 +2563,7 @@ static void __mptcp_destroy_sock(struct sock *sk) sk_stream_kill_queues(sk); xfrm_sk_free_policy(sk); sk_refcnt_debug_release(sk); + mptcp_dispose_initial_subflowg(msk); sock_put(sk); }