From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f51.google.com ([74.125.83.51]:43630 "EHLO mail-ee0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753689AbaA0N3C (ORCPT ); Mon, 27 Jan 2014 08:29:02 -0500 Received: by mail-ee0-f51.google.com with SMTP id b57so2268501eek.38 for ; Mon, 27 Jan 2014 05:29:01 -0800 (PST) Received: from localhost (host-115-115.kawo1.rwth-aachen.de. [134.130.115.115]) by mx.google.com with ESMTPSA id v7sm42519249eel.2.2014.01.27.05.29.00 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Mon, 27 Jan 2014 05:29:00 -0800 (PST) From: Gerhard Heift To: linux-btrfs@vger.kernel.org Subject: [PATCH RFCv2 3/6] btrfs: copy_to_sk returns EOVERFLOW for too small buffer Date: Mon, 27 Jan 2014 14:28:29 +0100 Message-Id: <1390829312-814-4-git-send-email-Gerhard@Heift.Name> In-Reply-To: <1390829312-814-1-git-send-email-Gerhard@Heift.Name> References: <1390829312-814-1-git-send-email-Gerhard@Heift.Name> Sender: linux-btrfs-owner@vger.kernel.org List-ID: 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 | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 919d928..9fa222d 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1883,8 +1883,15 @@ 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 overflow; + } + item_len = 0; + ret = -EOVERFLOW; + } if (sizeof(sh) + item_len + *sk_offset > buf_size) { ret = 1; @@ -1910,6 +1917,9 @@ static noinline int copy_to_sk(struct btrfs_root *root, } (*num_found)++; + if (ret) /* -EOVERFLOW from above */ + goto overflow; + if (*num_found >= sk->nr_items) break; } @@ -1990,7 +2000,8 @@ 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); @@ -2013,6 +2024,8 @@ 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); + if (ret == -EOVERFLOW) + ret = 0; if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) ret = -EFAULT; kfree(args); -- 1.8.5.3