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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 844CEC2BB54 for ; Tue, 7 Apr 2020 10:26:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5C47D2074B for ; Tue, 7 Apr 2020 10:26:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586255215; bh=X5su88Ck+vcA/+euMXd0fYE+MAIfr2mwTk/13mbANOA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mcKkHPAP8yE2C+alyDa/6TkE5biaO94Gl8vAX8+U9nkbDnzxla4hL82zdQfd4epRb qJ6oc9AOHgMCzGzKbIClxitutxTeMQ7lA4UplfLV87xz+MFrx7tjKnQy9xXjF5Y7r0 FtHaNdr6sEiCJrVgbGGeb84tLz4gADBFzaz/hE/o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729247AbgDGK0x (ORCPT ); Tue, 7 Apr 2020 06:26:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:39088 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729231AbgDGK0v (ORCPT ); Tue, 7 Apr 2020 06:26:51 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AA1B62074B; Tue, 7 Apr 2020 10:26:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586255210; bh=X5su88Ck+vcA/+euMXd0fYE+MAIfr2mwTk/13mbANOA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YxpOmALmX9EO4ddfyWF9FCADLAhXyP+g/KH0fPVaEzPJUVVemfxgfePa1uRw3Z0tm 5wpoIq6HV3erAFxLtpcRrowPqhBoobIpzwrfydo1phay9DUOOd1EYjC+FXxV9mHFxq YtitgZ4G4BTtn60bkXgSBxybTAbM9QqFor3IjstI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Qiujun Huang , Marcelo Ricardo Leitner , "David S. Miller" , syzbot+cea71eec5d6de256d54d@syzkaller.appspotmail.com Subject: [PATCH 5.6 05/29] sctp: fix refcount bug in sctp_wfree Date: Tue, 7 Apr 2020 12:22:02 +0200 Message-Id: <20200407101452.619901149@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200407101452.046058399@linuxfoundation.org> References: <20200407101452.046058399@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Qiujun Huang [ Upstream commit 5c3e82fe159622e46e91458c1a6509c321a62820 ] 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 Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sctp/socket.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -147,29 +147,44 @@ static void sctp_clear_owner_w(struct sc 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 * 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.