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 EEBEBC4332D for ; Fri, 20 Mar 2020 11:10:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B728A20732 for ; Fri, 20 Mar 2020 11:10:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="id84JLVQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727357AbgCTLKH (ORCPT ); Fri, 20 Mar 2020 07:10:07 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:34330 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726894AbgCTLKH (ORCPT ); Fri, 20 Mar 2020 07:10:07 -0400 Received: by mail-pg1-f196.google.com with SMTP id t3so2929002pgn.1; Fri, 20 Mar 2020 04:10:06 -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=8DC0Aw490tAtEteDyenp5f58iML9PsV1SemgO6pMc4k=; b=id84JLVQrc1pByXQ0kRoTprdf6KnYiB0t8lk6sCBFM9RdBrAOUPfbvVMzV9qiaL87i Wvp0xRICCAcPHoCFnMV8StTu3kzu2Ft7+QZOs/hvVTDp5jVlpx8UGbuABCSV+viP2YNC mRkOrLWy6XA1ndOvPPBf3ObeCBzPs4nSgMonij7C0tCECY+ai9NEJSlOfTAmCYY7HowQ ypNdhiNr1c38NknrwPv2fPDaonMx/BfmL48kL+8o3LrdM6Fc0w3969as+h8J+OwPzxsa HnPzBg+fibzVhbE8FTsCvmqAH8+x9IkWTNoFBL3QbbE2qNdzuWnBsNsWef+oiodFcD1e 9u1A== 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=8DC0Aw490tAtEteDyenp5f58iML9PsV1SemgO6pMc4k=; b=om4pd303E0mgA1BPEs76WWotfJpBWkwFrcgK7xyoelHDpjpVsJ2JZw0iMmcVq+nlJu +gCQI0PDrbgb6amHrjhs9kn1X3mcFtZPz8BVbIJWey2KfHnzBU6Bkn1sHEci1H2ehHru B9JEfMx1ttJoBBAXdlpmb4pylRxHYqwLP10CuUzURjEvkglvkBziDWWzyH5A2EKClFj1 kGGZdYH0gJEjLaqtss/zLf1mBTONyD9NE5J7NYOhqzaoSUq7N06mbnneuvSRkDmh0PQV b/Rg2ucj3kuxpBUJYECCS+81X7bQZasOcyzrDY0WDlNR6iwvCcmNhYcPA/CufCaVhYom WYGg== X-Gm-Message-State: ANhLgQ2JKfDZxtRw9RH0SYH4wXJrpfiueMatf5FKmY6fOp0nBKxqSXiY 83Gpc0F5nk/aUdPacOWjQIwcU/TOHCkWlg== X-Google-Smtp-Source: ADFU+vuVlMHmABpQyheyAcx3cY1cUhb6lfIhNDQ0xBjDWcqim11OoGyYbBSUhx+SgoDYa54pUcjH7w== X-Received: by 2002:a62:d144:: with SMTP id t4mr1396205pfl.10.1584702605420; Fri, 20 Mar 2020 04:10:05 -0700 (PDT) Received: from localhost ([161.117.239.120]) by smtp.gmail.com with ESMTPSA id u9sm5202984pfn.116.2020.03.20.04.10.04 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 20 Mar 2020 04:10:04 -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 v3] sctp: fix refcount bug in sctp_wfree Date: Fri, 20 Mar 2020 19:09:59 +0800 Message-Id: <20200320110959.2114-1-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: for the trouble SKB, it was in outq->transmitted queue sctp_outq_sack sctp_check_transmitted SKB was moved to outq->sack then throw away the sack queue SKB was deleted from outq->sack (but the datamsg held SKB at sctp_datamsg_to_asoc So, sctp_wfree was not called to destroy SKB) 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) this case in sctp_wfree SKB->sk was oldsk. 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Qiujun Huang Date: Fri, 20 Mar 2020 11:09:59 +0000 Subject: [PATCH v3] sctp: fix refcount bug in sctp_wfree Message-Id: <20200320110959.2114-1-hqjagain@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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 Do accounting for skb's real sk. In some case skb->sk != asoc->base.sk: for the trouble SKB, it was in outq->transmitted queue sctp_outq_sack sctp_check_transmitted SKB was moved to outq->sack then throw away the sack queue SKB was deleted from outq->sack (but the datamsg held SKB at sctp_datamsg_to_asoc So, sctp_wfree was not called to destroy SKB) 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) this case in sctp_wfree SKB->sk was oldsk. 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