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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99C37C77B71 for ; Sat, 15 Apr 2023 10:14:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229760AbjDOKOT (ORCPT ); Sat, 15 Apr 2023 06:14:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229717AbjDOKOS (ORCPT ); Sat, 15 Apr 2023 06:14:18 -0400 Received: from mail-wm1-x334.google.com (mail-wm1-x334.google.com [IPv6:2a00:1450:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B3313C1E for ; Sat, 15 Apr 2023 03:14:12 -0700 (PDT) Received: by mail-wm1-x334.google.com with SMTP id v20-20020a05600c471400b003ed8826253aso5934100wmo.0 for ; Sat, 15 Apr 2023 03:14:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1681553651; x=1684145651; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Wp4YF3nuXkkMv51GOsaMipzQK0xp4qUusETg3DPFN8g=; b=BHtiDOmCoIbmYqc+lRKC9AGbsuXXPVL59n4uKYjY2OHzdHn8LVXDunshclHU+Cg1Dc OxHlZ3AY7JngwWJZYDOykxe9onYS69uQFcAJ21iNUfrforTNYjP5sN/81R9irXmZjhEa +bBkv8UfBLUMLAkJgUCEO9IhX8e8oxVjQYMUp12QpQmOdfDwbj3uZ31qEZ1fwG6CHdo9 0qoUmYQ3ZINuIF5ytA5YGCU27dVvy2pcxBk2AMVSHHP0QXY6RYy1idnT1voA31bTfLKH AL+P4a6Z3grgQNZbfrXQS/BIrYwyAGVGRATaQ7FsG3KR4ncnHaFnxAMV21Cg3w0cQN/0 XNEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681553651; x=1684145651; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Wp4YF3nuXkkMv51GOsaMipzQK0xp4qUusETg3DPFN8g=; b=Nn0vvZdNbmiTExfHhoy+ysDnmmqW1doPcIPEC449FggJi06yOv4SLFw8t1rG3ELB9x VHuwOuwnfUM+Fj5uy836AVImMQgQBGbCyZ8YgqaCfO8aLv5auofsCOMDlZj5hnv3auIc zpuYRFRHLNTsdsgFyJCGrcIBVvlB1lVHwik0SMHfBczNFkTc8v0wfKn+iZc46WOaCi7+ ldJv6tE9oE0TJn54LAsTkMbdmpuSRkuQC145eHwyVVKV7Funt6qqtck5WOeohZbLhFcQ KMoCFc6jVZG2zuDKvrEQWSdD9VYiG1sgz6C2By+IAOI/udlE4Y4Uv7nZRNRBk/tbP9hw X8bg== X-Gm-Message-State: AAQBX9cNFAMS3K6wPV6ZyYM/kS37AbepwpY+5wFKNHjf182pco/4hqt2 1JflHiL4LrtSsdqPI65eq9m0JiG1GhU6ug== X-Google-Smtp-Source: AKy350ZnRrIEAh9ODFGhrLIHMBWqoSdQAdDh4IPJYB3zTYwrbrzYWGdPLDKWsYqgnJv2+0ZnF7Eyxg== X-Received: by 2002:a7b:ce89:0:b0:3f1:6788:a4b4 with SMTP id q9-20020a7bce89000000b003f16788a4b4mr1364773wmj.33.1681553650758; Sat, 15 Apr 2023 03:14:10 -0700 (PDT) Received: from localhost ([2a00:23c5:dc8c:8701:1663:9a35:5a7b:1d76]) by smtp.gmail.com with ESMTPSA id a1-20020a05600c224100b003f072b22dbbsm6272869wmm.16.2023.04.15.03.14.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 15 Apr 2023 03:14:09 -0700 (PDT) Date: Sat, 15 Apr 2023 11:14:08 +0100 From: Lorenzo Stoakes To: Tetsuo Handa Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 3/7] mm/gup: remove vmas parameter from get_user_pages_remote() Message-ID: <63d92734-2185-439c-bbc7-53a4720f5d4a@lucifer.local> References: <631001ecc556c5e348ff4f47719334c31f7bd592.1681547405.git.lstoakes@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Apr 15, 2023 at 06:52:41PM +0900, Tetsuo Handa wrote: > On 2023/04/15 18:08, Lorenzo Stoakes wrote: > > @@ -475,10 +474,14 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, > > gup_flags |= FOLL_SPLIT_PMD; > > /* Read the page with vaddr into memory */ > > ret = get_user_pages_remote(mm, vaddr, 1, gup_flags, > > - &old_page, &vma, NULL); > > + &old_page, NULL); > > if (ret <= 0) > > return ret; > > > > + vma = vma_lookup(mm, vaddr); > > + if (!vma) > > + goto put_old; > > + > > ret = verify_opcode(old_page, vaddr, &opcode); > > if (ret <= 0) > > goto put_old; > > This conversion looks wrong. > This causes returning a positive number when vma_lookup() returned NULL. > > * Return 0 (success) or a negative errno. > In reality it shouldn't be possible for vma to return NULL, I'm adding the checks to be extra careful. In any case you're right, attaching a -fix patch to avoid spam:- ----8<---- >From 0710d01ea69ad4e846fa1e56a40b253ff59714ac Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes Date: Sat, 15 Apr 2023 11:09:15 +0100 Subject: [PATCH] mm/gup: remove vmas parameter from get_user_pages_remote() Correct vma NULL check as indicated by Tetsuo. Signed-off-by: Lorenzo Stoakes --- kernel/events/uprobes.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index b21993cd2dcc..affe42a13eff 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -479,8 +479,10 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, return ret; vma = vma_lookup(mm, vaddr); - if (!vma) + if (!vma) { + ret = -EINVAL; goto put_old; + } ret = verify_opcode(old_page, vaddr, &opcode); if (ret <= 0) -- 2.40.0