From patchwork Wed Jan 22 13:00:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 11345693 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id ECA8E1820 for ; Wed, 22 Jan 2020 13:00:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CAC492467F for ; Wed, 22 Jan 2020 13:00:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="Id0p0/pu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729137AbgAVNAm (ORCPT ); Wed, 22 Jan 2020 08:00:42 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:37038 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728900AbgAVNAk (ORCPT ); Wed, 22 Jan 2020 08:00:40 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 482lrM6r0Bz9v4T1; Wed, 22 Jan 2020 14:00:35 +0100 (CET) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=Id0p0/pu; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id ER69ev4z_Xec; Wed, 22 Jan 2020 14:00:35 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 482lrM51BQz9v4T0; Wed, 22 Jan 2020 14:00:35 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1579698035; bh=IYuSNHph3xeKS9BqJ4P2sNK404BWtsrlVrUfzRg8JZc=; h=From:Subject:To:Cc:Date:From; b=Id0p0/punrqkIoihRIjlOTDIJUf8EAaYY/45qzeAcFcpIvcYgWSV7dABhL2qWd+Rd OrZCEwEeHWaDFQsMYorxbrJexxNque0AKSTnLknGxGBn0IXYhJ8P0sIFr5JDMOEa91 sZ3Li+AyYuqq/Ks/DIu38NLCzSiqIwLU7TDPZFEo= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id CD87C8B803; Wed, 22 Jan 2020 14:00:36 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id shOjK1liW11x; Wed, 22 Jan 2020 14:00:36 +0100 (CET) Received: from po14934vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.230.100]) by messagerie.si.c-s.fr (Postfix) with ESMTP id D917D8B7FA; Wed, 22 Jan 2020 14:00:35 +0100 (CET) Received: by po14934vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 9179F651E0; Wed, 22 Jan 2020 13:00:35 +0000 (UTC) Message-Id: From: Christophe Leroy Subject: [PATCH v1 1/6] fs/readdir: Fix filldir() and filldir64() use of user_access_begin() To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Linus Torvalds , Alexander Viro , Andrew Morton Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Date: Wed, 22 Jan 2020 13:00:35 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Some architectures grand full access to userspace regardless of the address/len passed to user_access_begin(), but other architectures only grand access to the requested area. For exemple, on 32 bits powerpc (book3s/32), access is granted by segments of 256 Mbytes. Modify filldir() and filldir64() to request the real area they need to get access to. Fixes: 9f79b78ef744 ("Convert filldir[64]() from __put_user() to unsafe_put_user()") Signed-off-by: Christophe Leroy --- fs/readdir.c | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) diff --git a/fs/readdir.c b/fs/readdir.c index d26d5ea4de7b..ef04e5e76c59 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -236,15 +236,11 @@ static int filldir(struct dir_context *ctx, const char *name, int namlen, if (dirent && signal_pending(current)) return -EINTR; - /* - * Note! This range-checks 'previous' (which may be NULL). - * The real range was checked in getdents - */ - if (!user_access_begin(dirent, sizeof(*dirent))) + if (dirent && unlikely(put_user(offset, &dirent->d_off))) goto efault; - if (dirent) - unsafe_put_user(offset, &dirent->d_off, efault_end); dirent = buf->current_dir; + if (!user_access_begin(dirent, reclen)) + goto efault; unsafe_put_user(d_ino, &dirent->d_ino, efault_end); unsafe_put_user(reclen, &dirent->d_reclen, efault_end); unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end); @@ -323,15 +319,11 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen, if (dirent && signal_pending(current)) return -EINTR; - /* - * Note! This range-checks 'previous' (which may be NULL). - * The real range was checked in getdents - */ - if (!user_access_begin(dirent, sizeof(*dirent))) + if (dirent && unlikely(put_user(offset, &dirent->d_off))) goto efault; - if (dirent) - unsafe_put_user(offset, &dirent->d_off, efault_end); dirent = buf->current_dir; + if (!user_access_begin(dirent, reclen)) + goto efault; unsafe_put_user(ino, &dirent->d_ino, efault_end); unsafe_put_user(reclen, &dirent->d_reclen, efault_end); unsafe_put_user(d_type, &dirent->d_type, efault_end);