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[2620:137:e000::1:18]) by mx.google.com with ESMTPS id pv12-20020a17090b3c8c00b001cbb0d0badbsi4489855pjb.111.2022.04.12.15.45.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Apr 2022 15:45:12 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=A4Jk68wM; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3B5A91B48DC; Tue, 12 Apr 2022 14:26:11 -0700 (PDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345729AbiDKKtV (ORCPT + 99 others); Mon, 11 Apr 2022 06:49:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231561AbiDKKtS (ORCPT ); Mon, 11 Apr 2022 06:49:18 -0400 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11D7A43ECC for ; Mon, 11 Apr 2022 03:47:05 -0700 (PDT) Received: by mail-pl1-x632.google.com with SMTP id n18so13495747plg.5 for ; Mon, 11 Apr 2022 03:47:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=D61e5PhtFJPcIJdrPl1gSUgNp3pemKHhA66zJEsV9FM=; b=A4Jk68wM4X0r58C8JBY86tyj7B6qU/KA0BUvsUrgdYgeFSQPF/0L6mUWUGtpL9BWoh QT53llRS+5kFsvzwsiKgwEeik+Gr7+6FILNA889tzzx782qbFHbldXEfpy+2w4FUV9b7 wF7XLqNylZxxCrW2P+3TGcYkQr+ybttO/B3tlzpFA/sDnth1BB1TjRMDVOe1rF91M/4t e4PgtHKnbCbzLxY8uTPe0XKjEmI2yj2g6l+qPmaw0n45MFHQqgVDXqQKzw+Nj6H0onZV q8vynE1L6tPyHigNfK6p3VrWNI/aF0ppwdv0m01vwSAbe4IROB/M3B3y2VZ2oGDy2Y39 fdGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=D61e5PhtFJPcIJdrPl1gSUgNp3pemKHhA66zJEsV9FM=; b=167DMPAGXrRWuP898w43yJ2gWL2wrjQpnlMtSySFPYuQ2o/UsGxSqPr3reUcor5/W4 9YCk6TAfVCaeZA4hTMZkLklhk82sypllTRHZylsJyJPQI+vAX7vDV+9Dzn/+v6UmBOMy Wuu8xRPA4BgVZbDZ1wv3LcG+/lA/M07BYurXuWDh1pweOT9nr2y6UuBQ7Cf2aXvVKuIH FxU4SXABjkr/8s5DrsjFVrY7NLq9kmYXMjnNfsTVHa0M/NzAzlf6CNtuNUGxaB+FmnXo se7EBItzM89g6uAzp3x/zc4wIuHaCmRedpwVrzEAeCUb6o3A3hYHLu8edrl+Cg1Wh11Z RDig== X-Gm-Message-State: AOAM5329uVXxOYBME3qwZIa4HFJHnLGpOQ9OTEDUR4s1z7LkFku99YHL GuYvUHcpgzLskjMH1hHgZSc9CBmg58wfP/jWKg== X-Received: by 2002:a17:90b:1803:b0:1c7:24c4:ab52 with SMTP id lw3-20020a17090b180300b001c724c4ab52mr35530871pjb.240.1649674024416; Mon, 11 Apr 2022 03:47:04 -0700 (PDT) MIME-Version: 1.0 References: <20220410114814.3920474-1-zheyuma97@gmail.com> In-Reply-To: From: Zheyu Ma Date: Mon, 11 Apr 2022 18:46:53 +0800 Message-ID: Subject: Re: [PATCH] tty: synclink_gt: Fix null-pointer-dereference in slgt_clean() To: Jiri Slaby Cc: Greg KH , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RDNS_NONE, SPF_HELO_NONE,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 11, 2022 at 6:13 PM Jiri Slaby wrote: > > On 10. 04. 22, 13:48, Zheyu Ma wrote: > > When the driver fails at alloc_hdlcdev(), and then we remove the driver > > module, we will get the following splat: > > > > [ 25.065966] general protection fault, probably for non-canonical address 0xdffffc0000000182: 0000 [#1] PREEMPT SMP KASAN PTI > > [ 25.066914] KASAN: null-ptr-deref in range [0x0000000000000c10-0x0000000000000c17] > > [ 25.069262] RIP: 0010:detach_hdlc_protocol+0x2a/0x3e0 > > [ 25.077709] Call Trace: > > [ 25.077924] > > [ 25.078108] unregister_hdlc_device+0x16/0x30 > > [ 25.078481] slgt_cleanup+0x157/0x9f0 [synclink_gt] > > > > Fix this by checking whether the 'info->netdev' is a null pointer first. > > Hi, > > LGTM > > Reviewed-by: Jiri Slaby > > Out of curiosity, do you use the driver, or you only do some static > analysis? In fact, neither. I test the driver via fuzzing in a simulated environment. Zheyu Ma