From patchwork Thu May 28 23:49:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 11577267 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 BB5E390 for ; Thu, 28 May 2020 23:50:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD43C2084C for ; Thu, 28 May 2020 23:50:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437765AbgE1XtX (ORCPT ); Thu, 28 May 2020 19:49:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44794 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437661AbgE1XtV (ORCPT ); Thu, 28 May 2020 19:49:21 -0400 Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22F6CC014D07; Thu, 28 May 2020 16:49:21 -0700 (PDT) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.93 #3 (Red Hat Linux)) id 1jeSH1-00HDnx-GS; Thu, 28 May 2020 23:49:19 +0000 From: Al Viro To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 4/6] switch readdir(2) to unsafe_copy_dirent_name() Date: Fri, 29 May 2020 00:49:17 +0100 Message-Id: <20200528234919.4104604-1-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200528234832.GA4103769@ZenIV.linux.org.uk> References: <20200528234832.GA4103769@ZenIV.linux.org.uk> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Al Viro ... and the same for its compat counterpart Signed-off-by: Al Viro --- fs/readdir.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) diff --git a/fs/readdir.c b/fs/readdir.c index ed6aaad451aa..a9085016a619 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -157,17 +157,18 @@ static int fillonedir(struct dir_context *ctx, const char *name, int namlen, } buf->result++; dirent = buf->dirent; - if (!access_ok(dirent, + if (!user_write_access_begin(dirent, (unsigned long)(dirent->d_name + namlen + 1) - (unsigned long)dirent)) goto efault; - if ( __put_user(d_ino, &dirent->d_ino) || - __put_user(offset, &dirent->d_offset) || - __put_user(namlen, &dirent->d_namlen) || - __copy_to_user(dirent->d_name, name, namlen) || - __put_user(0, dirent->d_name + namlen)) - goto efault; + unsafe_put_user(d_ino, &dirent->d_ino, efault_end); + unsafe_put_user(offset, &dirent->d_offset, efault_end); + unsafe_put_user(namlen, &dirent->d_namlen, efault_end); + unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); + user_write_access_end(); return 0; +efault_end: + user_write_access_end(); efault: buf->result = -EFAULT; return -EFAULT; @@ -424,17 +425,18 @@ static int compat_fillonedir(struct dir_context *ctx, const char *name, } buf->result++; dirent = buf->dirent; - if (!access_ok(dirent, + if (!user_write_access_begin(dirent, (unsigned long)(dirent->d_name + namlen + 1) - (unsigned long)dirent)) goto efault; - if ( __put_user(d_ino, &dirent->d_ino) || - __put_user(offset, &dirent->d_offset) || - __put_user(namlen, &dirent->d_namlen) || - __copy_to_user(dirent->d_name, name, namlen) || - __put_user(0, dirent->d_name + namlen)) - goto efault; + unsafe_put_user(d_ino, &dirent->d_ino, efault_end); + unsafe_put_user(offset, &dirent->d_offset, efault_end); + unsafe_put_user(namlen, &dirent->d_namlen, efault_end); + unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); + user_write_access_end(); return 0; +efault_end: + user_write_access_end(); efault: buf->result = -EFAULT; return -EFAULT;