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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=no 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 AF50FC7618B for ; Mon, 29 Jul 2019 15:02:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77BEE2067D for ; Mon, 29 Jul 2019 15:02:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="EprW1r+E"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="EprW1r+E" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728709AbfG2PCp (ORCPT ); Mon, 29 Jul 2019 11:02:45 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:36088 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727168AbfG2PCo (ORCPT ); Mon, 29 Jul 2019 11:02:44 -0400 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 3D4EF8EE128; Mon, 29 Jul 2019 08:02:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1564412564; bh=AXFFEJd9Z+18E4ObOxvkjLDLsngNOvQy6aoRiwcys2A=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=EprW1r+EW/YWTOUw/uvCXRsE7c7By6UIgumC4MaW1eJu2fXPEecjGfFRQfkdy0U2I B8HdedUX5X0f0fbVa0MDGNpR6c/0Wl600FHmM+Z5t1Yj7ayetkPnygB+bcqiLnCkvs r+9sqS+4sCpGDEZjL2W4X6Hl2wEe45cRXMEkmnWA= Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ql8M7lsLqgpc; Mon, 29 Jul 2019 08:02:44 -0700 (PDT) Received: from jarvis.lan (unknown [50.35.71.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id 943F48EE116; Mon, 29 Jul 2019 08:02:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1564412564; bh=AXFFEJd9Z+18E4ObOxvkjLDLsngNOvQy6aoRiwcys2A=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=EprW1r+EW/YWTOUw/uvCXRsE7c7By6UIgumC4MaW1eJu2fXPEecjGfFRQfkdy0U2I B8HdedUX5X0f0fbVa0MDGNpR6c/0Wl600FHmM+Z5t1Yj7ayetkPnygB+bcqiLnCkvs r+9sqS+4sCpGDEZjL2W4X6Hl2wEe45cRXMEkmnWA= Message-ID: <1564412562.3501.9.camel@HansenPartnership.com> Subject: Re: [PATCH] target: iscsi: iscsi_target_tpg: Fix a possible null-pointer dereference in iscsit_tpg_add_network_portal() From: James Bottomley To: Jia-Ju Bai , martin.petersen@oracle.com, kstewart@linuxfoundation.org, allison@lohutok.net, rfontana@redhat.com, tglx@linutronix.de, gregkh@linuxfoundation.org Cc: linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 29 Jul 2019 08:02:42 -0700 In-Reply-To: <20190729022956.18192-1-baijiaju1990@gmail.com> References: <20190729022956.18192-1-baijiaju1990@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2019-07-29 at 10:29 +0800, Jia-Ju Bai wrote: > In iscsit_tpg_add_network_portal(), there is an if statement on line > 496 > to check whether tpg->tpg_tiqn is NULL: > if (tpg->tpg_tiqn) > > When tpg->tpg_tiqn is NULL, it is used on line 508: > pr_debug(..., tpg->tpg_tiqn->tiqn, ...); > > Thus, a possible null-pointer dereference may occur. > > To fix this bug, tpg->tpg_tiqn is checked before being used. > > This bug is found by a static analysis tool STCheck written by us. I don't really think this is helpful. The first question is, is the implied might be NULL check correct? The tpg_tiqn is always set by a non-dummy driver and I think network configuration is only done for the non dummy driver, so I suspect the NULL check is wrong. Secondly even if the NULL check were correct, I think there's still a need for some debugging output, so the proposed patch also looks wrong. James