From patchwork Thu Jan 30 15:23:59 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerhard Heift X-Patchwork-Id: 3557791 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id F3AC39F2E9 for ; Thu, 30 Jan 2014 15:24:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E5DA3201C0 for ; Thu, 30 Jan 2014 15:24:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4A67201BB for ; Thu, 30 Jan 2014 15:24:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753471AbaA3PYR (ORCPT ); Thu, 30 Jan 2014 10:24:17 -0500 Received: from mail-ea0-f169.google.com ([209.85.215.169]:35946 "EHLO mail-ea0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753430AbaA3PYQ (ORCPT ); Thu, 30 Jan 2014 10:24:16 -0500 Received: by mail-ea0-f169.google.com with SMTP id h10so1734164eak.28 for ; Thu, 30 Jan 2014 07:24:15 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references; bh=z0Py4k2jEJMR7qhs/cmO+98DRSgt9LLMskz9BurA2lo=; b=X3PzSzvxQZ3HZeg15zQsjI8FBqFxaA2Etw8JK1UMcWU5z+RzCJtyC3gbQS60uOF53p PctFmx/iA9oZn3nTB559zcksVviasoDkhF9MfoOY1/VzhQD7CbfNrj4pT6gGxX7rgno8 uO8EzDkUpSqKy85r4txX/NzClvjSEiNGFAACWlup21EHJ4mk0Hdb4W4tSTMx3xl2rx4g 7+Xb7TNlT1TTUjjgjcRbQ3tK+qBtLJa6yU1+TNfTvLuY2HiKwX4NENu/28ST94/ua38b P7Ivr9k5bEGws39iR+DffznNx0QHa7PkkYIvxjVWdXA2P4DOCNS6XIhQcKPAT+5BL2Ao 9YEQ== X-Gm-Message-State: ALoCoQm5oSsAhd/j9Mf3haGDd8pdJ7g9bZyUtEuQd/uIR9VXO9Fgh2j5k14xHBuxwIChtpGhop4w X-Received: by 10.14.202.136 with SMTP id d8mr7854638eeo.46.1391095455805; Thu, 30 Jan 2014 07:24:15 -0800 (PST) Received: from localhost (host-115-115.kawo1.rwth-aachen.de. [134.130.115.115]) by mx.google.com with ESMTPSA id 46sm23592770ees.4.2014.01.30.07.24.14 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Thu, 30 Jan 2014 07:24:15 -0800 (PST) From: Gerhard Heift To: linux-btrfs@vger.kernel.org Subject: [PATCH RFCv4 3/7] btrfs: tree_search, copy_to_sk: return EOVERFLOW for too small buffer Date: Thu, 30 Jan 2014 16:23:59 +0100 Message-Id: <1391095443-20287-4-git-send-email-Gerhard@Heift.Name> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1391095443-20287-1-git-send-email-Gerhard@Heift.Name> References: <1391095443-20287-1-git-send-email-Gerhard@Heift.Name> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In copy_to_sk, if an item is too large for the given buffer, it now returns -EOVERFLOW instead of copying a search_header with len = 0. For backward compatibility for the first item it still copies such a header to the buffer, but not any other following items, which could have fitted. tree_search changes -EOVERFLOW back to 0 to behave similiar to the way it behaved before this patch. Signed-off-by: Gerhard Heift --- fs/btrfs/ioctl.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 9b66eac..4e32ac2 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1887,8 +1887,20 @@ static noinline int copy_to_sk(struct btrfs_root *root, if (!key_in_sk(key, sk)) continue; - if (sizeof(sh) + item_len > buf_size) + if (sizeof(sh) + item_len > buf_size) { + if (*num_found) { + ret = 1; + goto out; + } + + /* + * return one empty item back for v1, which does not + * handle -EOVERFLOW + */ + item_len = 0; + ret = -EOVERFLOW; + } if (sizeof(sh) + item_len + *sk_offset > buf_size) { ret = 1; @@ -1914,6 +1926,9 @@ static noinline int copy_to_sk(struct btrfs_root *root, } (*num_found)++; + if (ret) /* -EOVERFLOW from above */ + goto out; + if (*num_found >= sk->nr_items) { ret = 1; goto out; @@ -1992,7 +2007,8 @@ static noinline int search_ioctl(struct inode *inode, break; } - ret = 0; + if (ret > 0) + ret = 0; err: sk->nr_items = num_found; btrfs_free_path(path); @@ -2015,6 +2031,14 @@ static noinline int btrfs_ioctl_tree_search(struct file *file, inode = file_inode(file); ret = search_ioctl(inode, &args->key, sizeof(args->buf), args->buf); + + /* + * In the origin implementation an overflow is handled by returning a + * search header with a len of zero, so reset ret. + */ + if (ret == -EOVERFLOW) + ret = 0; + if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) ret = -EFAULT; kfree(args);