From patchwork Fri Mar 27 03:07:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qiujun Huang X-Patchwork-Id: 221754 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, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 844E0C2D0E7 for ; Fri, 27 Mar 2020 03:08:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BBAD2082D for ; Fri, 27 Mar 2020 03:08:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XqGi/tia" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727708AbgC0DH7 (ORCPT ); Thu, 26 Mar 2020 23:07:59 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:46902 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727446AbgC0DH7 (ORCPT ); Thu, 26 Mar 2020 23:07:59 -0400 Received: by mail-pf1-f195.google.com with SMTP id q3so3795798pff.13; Thu, 26 Mar 2020 20:07:58 -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=2DQUOCm1EaVk4TsyfJrUq1iAxjoNQGGgwCMFKg9aS9g=; b=XqGi/tiazfMdyxJUvUzP5R+WcHVs3t2gtjdaaJnkfxwd6AS3Dhon8D7T8Hvs3hezZG 1SBMyLISonSsAIo+qkFafQXCCedhzx5827FvRafihFmoGdDD0P2Dth9Rii76GU/STTj8 iwAWK+L7DT1iaDCn9gm7jpvOonVUh4lIgb1mFv+Yol0TnO46ESIqzlnPOVB0SE5wxiYD 5blJOI8ZUwyhNynM8/bgpZJLcBujN614V8M5oUJ0N9Q2agFzM6ZMXLjXCTWpF2X2KemX gBIOxAOKF1u2jz9c2THj1okZcOfZFAG2C4CmiQYhW04bGMi/Xdw8H4kmlcM1sjQQzLPS qEnQ== 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=2DQUOCm1EaVk4TsyfJrUq1iAxjoNQGGgwCMFKg9aS9g=; b=cdweE6YLI+wu/s+Guc4f8+JySQvJ0RIrhiwNzdfapops/AvDSEkcfptbASOLPU6K1N b2fQnZYK0yNDRo0/lhfxHw+jlQ/4pIySNs0ycLpINxvutUaO55MKVmVtpZR3eY+EPtNa vY08Sa+9xeRVYC34fwk9iE31tgv4/U1S63Y5yf2OkCdasHfAOziufZK0TyeHI+xQ5uMj FQ2OVrgiNI3i7Fr/6E72iynFsdGZIsSCpy2ZsMH88YFH1uV89NIcEAuLf0+uRq5BrYbK fMwFMnUzoDbzOKrObCvWUQ/IJr+VhRyava3icGJMTXnNDHgWs+C4cuTJGiGPGMKv3jNl 9tlw== X-Gm-Message-State: ANhLgQ14EZz+wy92G2NP1PVqmMVKPjSWYd0dXvHRshN8mdCzDMLsJXCt u4419REaslsv5jueKUKbJw7Go5ShIhrEVw== X-Google-Smtp-Source: ADFU+vvzLjoiyk6aa4bXaqKb0l9qNEJQaMPG0FyhsOBZ2iDmDjYTF2pETniPQE5M1pJVBQjo7k0WlA== X-Received: by 2002:a62:15cc:: with SMTP id 195mr12866413pfv.276.1585278478035; Thu, 26 Mar 2020 20:07:58 -0700 (PDT) Received: from localhost ([161.117.239.120]) by smtp.gmail.com with ESMTPSA id w31sm2750543pgl.84.2020.03.26.20.07.56 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 26 Mar 2020 20:07:57 -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 v6] sctp: fix refcount bug in sctp_wfree Date: Fri, 27 Mar 2020 11:07:51 +0800 Message-Id: <20200327030751.19404-1-hqjagain@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org We should iterate over the datamsgs to move all chunks(skbs) to newsk. The following case cause the bug: for the trouble SKB, it was in outq->transmitted list sctp_outq_sack sctp_check_transmitted SKB was moved to outq->sacked list then throw away the sack queue SKB was deleted from outq->sacked (but it was held by datamsg at sctp_datamsg_to_asoc So, sctp_wfree was not called here) then migrate happened sctp_for_each_tx_datachunk( sctp_clear_owner_w); sctp_assoc_migrate(); sctp_for_each_tx_datachunk( sctp_set_owner_w); SKB was not in the outq, and was not changed to newsk finally __sctp_outq_teardown sctp_chunk_put (for another skb) sctp_datamsg_put __kfree_skb(msg->frag_list) sctp_wfree (for SKB) SKB->sk was still oldsk (skb->sk != asoc->base.sk). Reported-and-tested-by: syzbot+cea71eec5d6de256d54d@syzkaller.appspotmail.com Signed-off-by: Qiujun Huang --- net/sctp/socket.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 1b56fc440606..f68076713162 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -147,29 +147,44 @@ static void sctp_clear_owner_w(struct sctp_chunk *chunk) skb_orphan(chunk->skb); } +#define traverse_and_process() \ +do { \ + msg = chunk->msg; \ + if (msg == prev_msg) \ + continue; \ + list_for_each_entry(c, &msg->chunks, frag_list) { \ + if ((clear && asoc->base.sk == c->skb->sk) || \ + (!clear && asoc->base.sk != c->skb->sk)) \ + cb(c); \ + } \ + prev_msg = msg; \ +} while (0) + static void sctp_for_each_tx_datachunk(struct sctp_association *asoc, + bool clear, void (*cb)(struct sctp_chunk *)) { + struct sctp_datamsg *msg, *prev_msg = NULL; struct sctp_outq *q = &asoc->outqueue; + struct sctp_chunk *chunk, *c; struct sctp_transport *t; - struct sctp_chunk *chunk; list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) list_for_each_entry(chunk, &t->transmitted, transmitted_list) - cb(chunk); + traverse_and_process(); list_for_each_entry(chunk, &q->retransmit, transmitted_list) - cb(chunk); + traverse_and_process(); list_for_each_entry(chunk, &q->sacked, transmitted_list) - cb(chunk); + traverse_and_process(); list_for_each_entry(chunk, &q->abandoned, transmitted_list) - cb(chunk); + traverse_and_process(); list_for_each_entry(chunk, &q->out_chunk_list, list) - cb(chunk); + traverse_and_process(); } static void sctp_for_each_rx_skb(struct sctp_association *asoc, struct sock *sk, @@ -9574,9 +9589,9 @@ static int sctp_sock_migrate(struct sock *oldsk, struct sock *newsk, * paths won't try to lock it and then oldsk. */ lock_sock_nested(newsk, SINGLE_DEPTH_NESTING); - sctp_for_each_tx_datachunk(assoc, sctp_clear_owner_w); + sctp_for_each_tx_datachunk(assoc, true, sctp_clear_owner_w); sctp_assoc_migrate(assoc, newsk); - sctp_for_each_tx_datachunk(assoc, sctp_set_owner_w); + sctp_for_each_tx_datachunk(assoc, false, sctp_set_owner_w); /* If the association on the newsk is already closed before accept() * is called, set RCV_SHUTDOWN flag.