From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Scott Bauer , Linus Torvalds Subject: [PATCH 4.6 95/96] vfs: ioctl: prevent double-fetch in dedupe ioctl Date: Mon, 8 Aug 2016 21:11:58 +0200 Message-Id: <20160808180248.084798121@linuxfoundation.org> In-Reply-To: <20160808180243.898163389@linuxfoundation.org> References: <20160808180243.898163389@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Scott Bauer commit 10eec60ce79187686e052092e5383c99b4420a20 upstream. This prevents a double-fetch from user space that can lead to to an undersized allocation and heap overflow. Fixes: 54dbc1517237 ("vfs: hoist the btrfs deduplication ioctl to the vfs") Signed-off-by: Scott Bauer Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/ioctl.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -590,6 +590,7 @@ static long ioctl_file_dedupe_range(stru goto out; } + same->dest_count = count; ret = vfs_dedupe_file_range(file, same); if (ret) goto out;