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 3A462C43217 for ; Mon, 14 Nov 2022 12:53:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237472AbiKNMxf (ORCPT ); Mon, 14 Nov 2022 07:53:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237473AbiKNMxe (ORCPT ); Mon, 14 Nov 2022 07:53:34 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2ADDF2BCB for ; Mon, 14 Nov 2022 04:53:33 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BEEC06109A for ; Mon, 14 Nov 2022 12:53:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91DEDC433C1; Mon, 14 Nov 2022 12:53:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1668430412; bh=+nPvoQzhrZBO9LeCZKH9gIjAg0JhSoFYgsMg4Hg9E3A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BeHcyisCy8QZktczWFYRkZLvYQok0bWGzfpsNNN/zoWQ65Wg0AeSpEfAKBZD6za0H pADJhIamZDm+wRa+sMuLxC7DvqW9S9LzelsOmbS6uxmdSeQSS/oy63GH3U+KRbF7e4 /zrq9yCLEEdgcI074ctjffIV/B61k0c4WbLdMmTk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stanislav Fomichev , Cong Wang , Daniel Borkmann , Jakub Sitnicki , John Fastabend , Sasha Levin Subject: [PATCH 5.15 020/131] bpf, sock_map: Move cancel_work_sync() out of sock lock Date: Mon, 14 Nov 2022 13:44:49 +0100 Message-Id: <20221114124449.574142755@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221114124448.729235104@linuxfoundation.org> References: <20221114124448.729235104@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Cong Wang [ Upstream commit 8bbabb3fddcd0f858be69ed5abc9b470a239d6f2 ] Stanislav reported a lockdep warning, which is caused by the cancel_work_sync() called inside sock_map_close(), as analyzed below by Jakub: psock->work.func = sk_psock_backlog() ACQUIRE psock->work_mutex sk_psock_handle_skb() skb_send_sock() __skb_send_sock() sendpage_unlocked() kernel_sendpage() sock->ops->sendpage = inet_sendpage() sk->sk_prot->sendpage = tcp_sendpage() ACQUIRE sk->sk_lock tcp_sendpage_locked() RELEASE sk->sk_lock RELEASE psock->work_mutex sock_map_close() ACQUIRE sk->sk_lock sk_psock_stop() sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED) cancel_work_sync() __cancel_work_timer() __flush_work() // wait for psock->work to finish RELEASE sk->sk_lock We can move the cancel_work_sync() out of the sock lock protection, but still before saved_close() was called. Fixes: 799aa7f98d53 ("skmsg: Avoid lock_sock() in sk_psock_backlog()") Reported-by: Stanislav Fomichev Signed-off-by: Cong Wang Signed-off-by: Daniel Borkmann Tested-by: Jakub Sitnicki Acked-by: John Fastabend Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20221102043417.279409-1-xiyou.wangcong@gmail.com Signed-off-by: Sasha Levin --- include/linux/skmsg.h | 2 +- net/core/skmsg.c | 7 ++----- net/core/sock_map.c | 7 ++++--- 3 files changed, 7 insertions(+), 9 deletions(-) diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index ee7c67d8442d..ba015a77238a 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -382,7 +382,7 @@ static inline void sk_psock_report_error(struct sk_psock *psock, int err) } struct sk_psock *sk_psock_init(struct sock *sk, int node); -void sk_psock_stop(struct sk_psock *psock, bool wait); +void sk_psock_stop(struct sk_psock *psock); #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock); diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 680f51f8974a..f562f7e2bdc7 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -797,16 +797,13 @@ static void sk_psock_link_destroy(struct sk_psock *psock) } } -void sk_psock_stop(struct sk_psock *psock, bool wait) +void sk_psock_stop(struct sk_psock *psock) { spin_lock_bh(&psock->ingress_lock); sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED); sk_psock_cork_free(psock); __sk_psock_zap_ingress(psock); spin_unlock_bh(&psock->ingress_lock); - - if (wait) - cancel_work_sync(&psock->work); } static void sk_psock_done_strp(struct sk_psock *psock); @@ -844,7 +841,7 @@ void sk_psock_drop(struct sock *sk, struct sk_psock *psock) sk_psock_stop_verdict(sk, psock); write_unlock_bh(&sk->sk_callback_lock); - sk_psock_stop(psock, false); + sk_psock_stop(psock); INIT_RCU_WORK(&psock->rwork, sk_psock_destroy); queue_rcu_work(system_wq, &psock->rwork); diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 6eef46eafb3e..4f4bc163a223 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -1541,7 +1541,7 @@ void sock_map_destroy(struct sock *sk) saved_destroy = psock->saved_destroy; sock_map_remove_links(sk, psock); rcu_read_unlock(); - sk_psock_stop(psock, false); + sk_psock_stop(psock); sk_psock_put(sk, psock); saved_destroy(sk); } @@ -1564,9 +1564,10 @@ void sock_map_close(struct sock *sk, long timeout) saved_close = psock->saved_close; sock_map_remove_links(sk, psock); rcu_read_unlock(); - sk_psock_stop(psock, true); - sk_psock_put(sk, psock); + sk_psock_stop(psock); release_sock(sk); + cancel_work_sync(&psock->work); + sk_psock_put(sk, psock); saved_close(sk, timeout); } EXPORT_SYMBOL_GPL(sock_map_close); -- 2.35.1