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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 ADF01C18E5B for ; Tue, 17 Mar 2020 15:55:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84DAF20663 for ; Tue, 17 Mar 2020 15:55:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="irfrBskV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726765AbgCQPzo (ORCPT ); Tue, 17 Mar 2020 11:55:44 -0400 Received: from mail-pj1-f65.google.com ([209.85.216.65]:55541 "EHLO mail-pj1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726643AbgCQPzo (ORCPT ); Tue, 17 Mar 2020 11:55:44 -0400 Received: by mail-pj1-f65.google.com with SMTP id mj6so10173736pjb.5; Tue, 17 Mar 2020 08:55:43 -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; bh=rIOYXa4n3W4fvDIFexK8Xd1iAbQHd2/NWX4UF2y8JPU=; b=irfrBskVIzOYnt/8r4tZQkRb68wX1xdH3cibG7ArPih3W4C8DDXVzgNH550GQ96uAr jqoYAlgRrigTEqn3/aSlfNxHsiqOPz8uSpuxx032eJ1yTZFg7zVtabnFhEjkdfuXwHQC ZptWEZfY/eBxexy70Z6S05vR1GuZjwB8UEArvF4djW+XTlobg7LpVrFmKkUJ5IAuD9w4 ShHyFljj8mHxonbV1k6VGzmLVXAQVDsiD3Fv5iYzEM0Cp6vv1kPRKTZQ+q+ejfWOhSL3 l6ZOb71iiAsJcf3s/dNYOvvI/VIngpu4fwhYmDyFnaZorpKvJ5cNbswj6fBnOkCZh8CM NyFw== 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; bh=rIOYXa4n3W4fvDIFexK8Xd1iAbQHd2/NWX4UF2y8JPU=; b=kzf0S5W4ROoCDhdY7wzm8EHP5t0ArTNqeqou1uVvNVr/LAfD8jEnD9vX84rNHyY9Ed MN9Ba83VDW3FqgNf03+Hj77YKLvQbAs5V3mYQIkYQl6qd64gN3kqEutHEeE9mNtdQiLD x1Bde86f8brDkn27UPfxoJQskK6hQrlI+Pedy/SJH7iqW6Vlv/tRxP2UMMgHScGuPile wTP5tU0f/AJPAW7nsorPWJfsLvt5ygZ2sNm/hamD7cHsSl0PzESxJOKmUfREHuXuqch2 /gTIWVHBVcB6lqWHsFmHs/25TJhszxEg8hPbOq6VciyuxnMW74aTKwu7m8be50clQXrI ygSw== X-Gm-Message-State: ANhLgQ18q5Mwu8Bm105BZuGWJ1AcQBDku7XdXDn7nkRipi3DvKtGoFfG UkczOs8dvp3lqyMel87dDPQ= X-Google-Smtp-Source: ADFU+vsXJcKIHwYeeKLVHimqaIiwGZKzfpf0o1uTLHXjAzQQxGHWA+wfsYGrjvu6bZ6GZ6w3hOSWCg== X-Received: by 2002:a17:902:d712:: with SMTP id w18mr5146760ply.238.1584460542597; Tue, 17 Mar 2020 08:55:42 -0700 (PDT) Received: from localhost ([161.117.239.120]) by smtp.gmail.com with ESMTPSA id s19sm3665027pfh.218.2020.03.17.08.55.40 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 17 Mar 2020 08:55:41 -0700 (PDT) From: Qiujun Huang To: marcelo.leitner@gmail.com, davem@davemloft.net Cc: vyasevich@gmail.com, nhorman@tuxdriver.com, kuba@kernel.org, linux-sctp@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, anenbupt@gmail.com, Qiujun Huang Subject: [PATCH v2] sctp: fix refcount bug in sctp_wfree Date: Tue, 17 Mar 2020 23:55:36 +0800 Message-Id: <20200317155536.10227-1-hqjagain@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Do accounting for skb's real sk. In some case skb->sk != asoc->base.sk: migrate routing sctp_check_transmitted routing ------------ --------------- lock_sock_nested(); mv the transmitted skb to the it's local tlist sctp_for_each_tx_datachunk( sctp_clear_owner_w); sctp_assoc_migrate(); sctp_for_each_tx_datachunk( sctp_set_owner_w); put the skb back to the assoc lists ---------------------------------------------------- The skbs which held bysctp_check_transmitted were not changed to newsk. They were not dealt with by sctp_for_each_tx_datachunk (sctp_clear_owner_w/sctp_set_owner_w). It looks only trouble here so handling it in sctp_wfree is enough. Reported-and-tested-by: syzbot+cea71eec5d6de256d54d@syzkaller.appspotmail.com Signed-off-by: Qiujun Huang --- net/sctp/socket.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 1b56fc440606..5f5c28b30e25 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -9080,7 +9080,7 @@ static void sctp_wfree(struct sk_buff *skb) { struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg; struct sctp_association *asoc = chunk->asoc; - struct sock *sk = asoc->base.sk; + struct sock *sk = skb->sk; sk_mem_uncharge(sk, skb->truesize); sk->sk_wmem_queued -= skb->truesize + sizeof(struct sctp_chunk); @@ -9109,7 +9109,7 @@ static void sctp_wfree(struct sk_buff *skb) } sock_wfree(skb); - sctp_wake_up_waiters(sk, asoc); + sctp_wake_up_waiters(asoc->base.sk, asoc); sctp_association_put(asoc); } -- 2.17.1