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=-22.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 2741CC4338F for ; Fri, 23 Jul 2021 12:28:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1081060720 for ; Fri, 23 Jul 2021 12:28:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234845AbhGWLra (ORCPT ); Fri, 23 Jul 2021 07:47:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:55636 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234832AbhGWLra (ORCPT ); Fri, 23 Jul 2021 07:47:30 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 445F860E8C; Fri, 23 Jul 2021 12:27:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627043284; bh=/hiAX5CAjW6tGqppGXooRjBKQ0fykryiFtk5xbyBL5w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ClM4itRigdwhpcbeJosSM1hJJCQiYijXqEk3LxM+YdmuKWCUCH8IdiJ3lGbpzfxqk pKfgrap4urO1oNLjGhtL6LzgSoPdbAMSyC7MX78P4GauiCg7BAkp7g0FsrW3zmzHSu Qa81UgbMGcjw2Aec6h/anR3ek2259WbMVLoEl8Fj6PdPPQVQxZTSer39iDunDlczIh z5RcHqPDHG36E/W7yjtjNj0p7RDo+MM05X/GMNwaktWmWfb30fmsBlvHmjfMNK5Q2D zUWAc056lCBP08V5ucxzraP/HxeO6vzZLJ/dtbGWRefNf41WnzMMqHe4xEw7wWtS2H lRmfmeuW9OZ7A== Date: Fri, 23 Jul 2021 17:57:53 +0530 From: Manivannan Sadhasivam To: Pavel Skripkin Cc: davem@davemloft.net, kuba@kernel.org, bjorn.andersson@sonymobile.com, courtney.cavin@sonymobile.com, linux-arm-msm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+35a511c72ea7356cdcf3@syzkaller.appspotmail.com Subject: Re: [PATCH] net: qrtr: fix memory leak in qrtr_local_enqueue Message-ID: <20210723122753.GA3739@thinkpad> References: <20210722161625.6956-1-paskripkin@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210722161625.6956-1-paskripkin@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Thu, Jul 22, 2021 at 07:16:25PM +0300, Pavel Skripkin wrote: > Syzbot reported memory leak in qrtr. The problem was in unputted > struct sock. qrtr_local_enqueue() function calls qrtr_port_lookup() > which takes sock reference if port was found. Then there is the following > check: > > if (!ipc || &ipc->sk == skb->sk) { > ... > return -ENODEV; > } > > Since we should drop the reference before returning from this function and > ipc can be non-NULL inside this if, we should add qrtr_port_put() inside > this if. > > Fixes: bdabad3e363d ("net: Add Qualcomm IPC router") > Reported-and-tested-by: syzbot+35a511c72ea7356cdcf3@syzkaller.appspotmail.com > Signed-off-by: Pavel Skripkin Reviewed-by: Manivannan Sadhasivam It'd be good if this patch can be extended to fix one more corner case here: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/net/qrtr/qrtr.c#n522 Thanks, Mani > --- > net/qrtr/qrtr.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c > index e6f4a6202f82..d5ce428d0b25 100644 > --- a/net/qrtr/qrtr.c > +++ b/net/qrtr/qrtr.c > @@ -839,6 +839,8 @@ static int qrtr_local_enqueue(struct qrtr_node *node, struct sk_buff *skb, > > ipc = qrtr_port_lookup(to->sq_port); > if (!ipc || &ipc->sk == skb->sk) { /* do not send to self */ > + if (ipc) > + qrtr_port_put(ipc); > kfree_skb(skb); > return -ENODEV; > } > -- > 2.32.0 >