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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 87414C10F03 for ; Wed, 24 Apr 2019 00:21:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 49DDC2089F for ; Wed, 24 Apr 2019 00:21:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556065319; bh=Bdt1EDkEUlum3F7qDy7HGfQ+9zhzsg34Q4ZJLeltAhY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=U1OlZaLnRVgosdr6M+vfttPMvqmwkRS1Tw8W/TlDjfBmg6eQW6NfwXzzM3Kf/qfbX 9+XOLQLSV9QOKqIYZpMHwNmpVcbJDV/lJmQL1lhbxRqX6XWx4h7wNFC8crnQehyS/S SM7PjL7DtihGo4qJsXeYPBDJA3b+Mh3nny+V535A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728797AbfDXAV6 (ORCPT ); Tue, 23 Apr 2019 20:21:58 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:37365 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728536AbfDXAV6 (ORCPT ); Tue, 23 Apr 2019 20:21:58 -0400 Received: by mail-pl1-f193.google.com with SMTP id w23so8339899ply.4; Tue, 23 Apr 2019 17:21:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=u+YkNJXUH195AbLZVr2IK4q1fxv4Pwzn3yATf1qSgdE=; b=uAbX+O0NBV6Z8+Wl/P2srWv9yBo56rmsOyJ1k3ZwjDiKU0j3LkfFadDx6mvhKoSmRk LHXuT1eo8xTeGawnsdGKrEqQF8gU8Xi0POJ7tES7cE2Kvueke3Jjy9iilpyi4B5iMoRc vXH9FfYAXLc3GwUDQTLCUvXQCMpsVy9qlv06j8pnOayTWUFr7ZsN+fmLsMzf0J+TpnYb trJa8gzXO+nSH7QyQUWXbcmr01AuADjSssOWv2ab4O1Yf1fowxpJWIxco5V1Oc5Dfocv WCLbLzdVKVx2ZuKGf0xPPM0W8jCCzhM/24j4hyZgVNPlMjRDKApJvg+3tB8gjXxVwfly f67g== X-Gm-Message-State: APjAAAWAyxd0lui3ZQU/qM4r3pm2ybDQ1HCTr2t6hsRQjU5uftQ8nMPM 5jF031Uvj0hCz2pJ9CCQCZ8= X-Google-Smtp-Source: APXvYqzH0TJahx3G25QTHrpT7CirvmVa96+uIEUmVk2f0ev6a1QsXlWLIZYTYKkd8mdZRIY/nspAuQ== X-Received: by 2002:a17:902:a9c7:: with SMTP id b7mr28826817plr.145.1556065317294; Tue, 23 Apr 2019 17:21:57 -0700 (PDT) Received: from localhost ([2601:647:4700:2953:e96c:d7df:9526:1357]) by smtp.gmail.com with ESMTPSA id a17sm30480851pfj.123.2019.04.23.17.21.56 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 23 Apr 2019 17:21:56 -0700 (PDT) Date: Tue, 23 Apr 2019 17:21:55 -0700 From: Moritz Fischer To: Wen Yang Cc: linux-kernel@vger.kernel.org, wang.yi59@zte.com.cn, Alan Tull , Moritz Fischer , Nicolas Saenz Julienne , linux-fpga@vger.kernel.org Subject: Re: [PATCH] fpga: stratix10-soc: fix use-after-free on s10_init() Message-ID: <20190424002155.GA15154@archbook> References: <1556062325-26141-1-git-send-email-wen.yang99@zte.com.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1556062325-26141-1-git-send-email-wen.yang99@zte.com.cn> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Wen, On Wed, Apr 24, 2019 at 07:32:05AM +0800, Wen Yang wrote: > The refcount of fw_np has already been decreased by of_find_matching_node() > so it shouldn't be used anymore. > This patch adds an of_node_get() before of_find_matching_node() to avoid > the use-after-free problem. > > Fixes: e7eef1d7633a ("fpga: add intel stratix10 soc fpga manager driver") > Signed-off-by: Wen Yang > Cc: Alan Tull > Cc: Moritz Fischer > Cc: Nicolas Saenz Julienne > Cc: linux-fpga@vger.kernel.org > Cc: linux-kernel@vger.kernel.org Reviewed-by: Moritz Fischer > --- > drivers/fpga/stratix10-soc.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c > index 13851b3..215d337 100644 > --- a/drivers/fpga/stratix10-soc.c > +++ b/drivers/fpga/stratix10-soc.c > @@ -507,12 +507,16 @@ static int __init s10_init(void) > if (!fw_np) > return -ENODEV; > > + of_node_get(fw_np); > np = of_find_matching_node(fw_np, s10_of_match); > - if (!np) > + if (!np) { > + of_node_put(fw_np); > return -ENODEV; > + } > > of_node_put(np); > ret = of_platform_populate(fw_np, s10_of_match, NULL, NULL); > + of_node_put(fw_np); > if (ret) > return ret; > > -- > 2.9.5 > Thanks, Moritz