From patchwork Mon Jul 19 21:48:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Fastabend X-Patchwork-Id: 12386979 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB259C07E9B for ; Mon, 19 Jul 2021 22:47:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EBE256112D for ; Mon, 19 Jul 2021 22:47:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359786AbhGSVwv (ORCPT ); Mon, 19 Jul 2021 17:52:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243039AbhGSVTV (ORCPT ); Mon, 19 Jul 2021 17:19:21 -0400 Received: from mail-io1-xd2c.google.com (mail-io1-xd2c.google.com [IPv6:2607:f8b0:4864:20::d2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8B69C0613E3; Mon, 19 Jul 2021 14:49:15 -0700 (PDT) Received: by mail-io1-xd2c.google.com with SMTP id z9so21704706iob.8; Mon, 19 Jul 2021 14:49:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Oe1SKP5YIMosFqeN5ivgaQq1fUhcitjsPyLRfiW25uM=; b=aAc7KRItp6RQv4Tk/+D4sxiZR55bYF24kfN2s/eixizGz3jj31OrzGBcAzBMX2uZto +/8xO3G6O69EH30T28uaHLe8kk3LeMw0BeArWa1hcihWuP6mi9A7ik/jw60J4C3cjYiu at6fnRgFrxqkxfA/TOk8JSRJxGRIBwSyp9QYNjf5xk+FKqzBe3ArbDXJJdNB2r/fbz/3 Q5vTtGCf9BdgHHGM9Hg+rReiNPjTj6VPu7EQRn71q8IHT1Nii3L2LQY+5BAM++7jpXz5 77py+gCTEMRxBZRFHvmK23FBB6qIEqSpNuREcBmx/069tTU21iwZdo8lYeb/vO4RyOlC sZCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Oe1SKP5YIMosFqeN5ivgaQq1fUhcitjsPyLRfiW25uM=; b=EQWlisGA12r/B+aVWc2oXQr01xdCgc+3O1y7YDcwLMlOoR7IoJeB734VhxadZhF0ge +xOPcxyfSKhb3aSIspYfa7jdSnp9nTCYFGXspMqhOepKha1SS8WpG0blri0uHTyoWC0p 8cVYFMOP33QCAortlQ/eB7fFPqFbuwOIkgUBKGjqAaex0TV71NW7kOdAHMKyUuPiSBIE aMOhEmtVa+R89cYjqYV8B6qam+/dxOAeZayrpdT8MXbf8oqC3y/GtacRng7MuX8vpLGc cjX16Hp+WC0DdXK7rCG5xZ0792gSpnTLDnCIueMlkDqLiOZJti97HhKZUO01rZyzXXzt RcbQ== X-Gm-Message-State: AOAM531AKUpqo4rH+urMyw2Th2syNmX+dk8FLRz7uqPzFu28JnXfE9U6 qZ7trUP9xbtknn15nXIqqdU= X-Google-Smtp-Source: ABdhPJxN1SSqIuzUGiMMZL7aBZF1LP8up5CTa2MaVakgn2LWSGWPKUqQhnWxhrSHw2GCIV2wHpXMxw== X-Received: by 2002:a5e:9306:: with SMTP id k6mr21206715iom.157.1626731355460; Mon, 19 Jul 2021 14:49:15 -0700 (PDT) Received: from john-XPS-13-9370.lan ([172.243.157.240]) by smtp.gmail.com with ESMTPSA id d14sm10124758iln.48.2021.07.19.14.49.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Jul 2021 14:49:15 -0700 (PDT) From: John Fastabend To: jakub@cloudflare.com, daniel@iogearbox.net, xiyou.wangcong@gmail.com, alexei.starovoitov@gmail.com Cc: john.fastabend@gmail.com, bpf@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH bpf 3/3] bpf, sockmap: fix memleak on ingress msg enqueue Date: Mon, 19 Jul 2021 14:48:34 -0700 Message-Id: <20210719214834.125484-4-john.fastabend@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210719214834.125484-1-john.fastabend@gmail.com> References: <20210719214834.125484-1-john.fastabend@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net If backlog handler is running during a tear down operation we may enqueue data on the ingress msg queue while tear down is trying to free it. sk_psock_backlog() sk_psock_handle_skb() skb_psock_skb_ingress() sk_psock_skb_ingress_enqueue() sk_psock_queue_msg(psock,msg) spin_lock(ingress_lock) sk_psock_zap_ingress() _sk_psock_purge_ingerss_msg() _sk_psock_purge_ingress_msg() -- free ingress_msg list -- spin_unlock(ingress_lock) spin_lock(ingress_lock) list_add_tail(msg,ingress_msg) <- entry on list with no on left to free it. spin_unlock(ingress_lock) To fix we only enqueue from backlog if the ENABLED bit is set. The tear down logic clears the bit with ingress_lock set so we wont enqueue the msg in the last step. Fixes: 799aa7f98d53 ("skmsg: Avoid lock_sock() in sk_psock_backlog()") Signed-off-by: John Fastabend --- include/linux/skmsg.h | 54 ++++++++++++++++++++++++++++--------------- net/core/skmsg.c | 6 ----- 2 files changed, 35 insertions(+), 25 deletions(-) diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index 96f319099744..883638888f93 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -285,11 +285,45 @@ static inline struct sk_psock *sk_psock(const struct sock *sk) return rcu_dereference_sk_user_data(sk); } +static inline void sk_psock_set_state(struct sk_psock *psock, + enum sk_psock_state_bits bit) +{ + set_bit(bit, &psock->state); +} + +static inline void sk_psock_clear_state(struct sk_psock *psock, + enum sk_psock_state_bits bit) +{ + clear_bit(bit, &psock->state); +} + +static inline bool sk_psock_test_state(const struct sk_psock *psock, + enum sk_psock_state_bits bit) +{ + return test_bit(bit, &psock->state); +} + +static void sock_drop(struct sock *sk, struct sk_buff *skb) +{ + sk_drops_add(sk, skb); + kfree_skb(skb); +} + +static inline void drop_sk_msg(struct sk_psock *psock, struct sk_msg *msg) +{ + if (msg->skb) + sock_drop(psock->sk, msg->skb); + kfree(msg); +} + static inline void sk_psock_queue_msg(struct sk_psock *psock, struct sk_msg *msg) { spin_lock_bh(&psock->ingress_lock); - list_add_tail(&msg->list, &psock->ingress_msg); + if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) + list_add_tail(&msg->list, &psock->ingress_msg); + else + drop_sk_msg(psock, msg); spin_unlock_bh(&psock->ingress_lock); } @@ -406,24 +440,6 @@ static inline void sk_psock_restore_proto(struct sock *sk, psock->psock_update_sk_prot(sk, psock, true); } -static inline void sk_psock_set_state(struct sk_psock *psock, - enum sk_psock_state_bits bit) -{ - set_bit(bit, &psock->state); -} - -static inline void sk_psock_clear_state(struct sk_psock *psock, - enum sk_psock_state_bits bit) -{ - clear_bit(bit, &psock->state); -} - -static inline bool sk_psock_test_state(const struct sk_psock *psock, - enum sk_psock_state_bits bit) -{ - return test_bit(bit, &psock->state); -} - static inline struct sk_psock *sk_psock_get(struct sock *sk) { struct sk_psock *psock; diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 5d956e91d05a..3ee407bed768 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -584,12 +584,6 @@ static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb, return sk_psock_skb_ingress(psock, skb); } -static void sock_drop(struct sock *sk, struct sk_buff *skb) -{ - sk_drops_add(sk, skb); - kfree_skb(skb); -} - static void sk_psock_skb_state(struct sk_psock *psock, struct sk_psock_work_state *state, struct sk_buff *skb,