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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 233C8C2BA1A for ; Tue, 7 Apr 2020 18:19:22 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 704DC20768 for ; Tue, 7 Apr 2020 18:19:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="e/axrASd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 704DC20768 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=daFQ1qHcOsgQBU4X6ZDf/tjxT25LOCrodKCAmBhHp5s=; b=e/axrASdNi5nqE SKT3aqm2cEpE9TIqJNAm6uUoUBwo/DQQBjkoG3ADDXBzGfm1zROz8u8p7zGXsEVPy6CXsAiBDlm4g /COCDjUsqE7YIGtL2aWCkQZjXv5nqzNpcYlcIwwSykLP9y5JAEZzattsz/RnRry2ZZUQEbnhNVowb udSBICWEPmTPFqdrO/ZNCzXueIYvYwt2KKlO1ThQ0U/tc1FYxg4+ZlldWrOZh54gSmOZH2hixzzMr 7U2s/hFKCRaF6/jfRDDxelb0q6BfAVtqkBAYmvGQ+dJVLWlQFws9HmfL1lxHXueYpM/tSG87qiuGU iDasrK3hk62u22M9nN3A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jLsob-0003Cy-Jg; Tue, 07 Apr 2020 18:19:13 +0000 Received: from mga17.intel.com ([192.55.52.151]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jLsoY-0003BA-JX for linux-mediatek@lists.infradead.org; Tue, 07 Apr 2020 18:19:11 +0000 IronPort-SDR: Uz//XkFb8aET2cnppP2vJQ1FDOjuyaJX3q/+nCPdRF6MR4S2T2GTTBA0X2YnZrgHJ8upKBupKF awgrB3dzKF0Q== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Apr 2020 11:19:08 -0700 IronPort-SDR: hrIdburDaMCzTAQyPcSF6hxKn0vdzYIyj0JgJyyQtUugCGrjCw8SK7PRdi+nBnpzQcRmt5bpho ZdVHFyZ+P7BA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,356,1580803200"; d="scan'208";a="451317416" Received: from iweiny-desk2.sc.intel.com ([10.3.52.147]) by fmsmga005.fm.intel.com with ESMTP; 07 Apr 2020 11:19:08 -0700 Date: Tue, 7 Apr 2020 11:19:08 -0700 From: Ira Weiny To: Miles Chen Subject: Re: [PATCH] mm/gup: fix null pointer dereference detected by coverity Message-ID: <20200407181908.GB94792@iweiny-DESK2.sc.intel.com> References: <20200407095107.1988-1-miles.chen@mediatek.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200407095107.1988-1-miles.chen@mediatek.com> User-Agent: Mutt/1.11.1 (2018-12-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200407_111910_685309_619E6EA7 X-CRM114-Status: GOOD ( 14.62 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-mm@kvack.org, Andrew Morton , linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, wsd_upstream@mediatek.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Tue, Apr 07, 2020 at 05:51:07PM +0800, Miles Chen wrote: > In fixup_user_fault(), it is possible that unlocked is NULL, > so we should test unlocked before using it. > > For example, in arch/arc/kernel/process.c, NULL is passed > to fixup_user_fault(). > > SYSCALL_DEFINE3(arc_usr_cmpxchg, int *, uaddr, int, expected, int, new) > { > ... > ret = fixup_user_fault(current, current->mm, (unsigned long) uaddr, > FAULT_FLAG_WRITE, NULL); > ... > } > > Fixes: 4a9e1cda2748 ("mm: bring in additional flag for fixup_user_fault to signal unlock") > Signed-off-by: Miles Chen Reviewed-by: Ira Weiny > --- > mm/gup.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/gup.c b/mm/gup.c > index da3e03185144..a68d11dc232d 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -1230,7 +1230,8 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm, > if (ret & VM_FAULT_RETRY) { > down_read(&mm->mmap_sem); > if (!(fault_flags & FAULT_FLAG_TRIED)) { > - *unlocked = true; > + if (unlocked) > + *unlocked = true; > fault_flags |= FAULT_FLAG_TRIED; > goto retry; > } > -- > 2.18.0 _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek