From patchwork Sat Apr 12 11:33:13 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Jaeger X-Patchwork-Id: 3972911 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 2F72BBFF02 for ; Sat, 12 Apr 2014 11:40:36 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6AD1E20270 for ; Sat, 12 Apr 2014 11:40:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0B9920263 for ; Sat, 12 Apr 2014 11:40:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756143AbaDLLkb (ORCPT ); Sat, 12 Apr 2014 07:40:31 -0400 Received: from smtprelay03.ispgateway.de ([80.67.31.41]:44833 "EHLO smtprelay03.ispgateway.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756043AbaDLLka (ORCPT ); Sat, 12 Apr 2014 07:40:30 -0400 X-Greylist: delayed 367 seconds by postgrey-1.27 at vger.kernel.org; Sat, 12 Apr 2014 07:40:30 EDT Received: from [92.231.101.166] (helo=betelgeuse.mikrowelle.local) by smtprelay03.ispgateway.de with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.68) (envelope-from ) id 1WYwBj-0007nj-T6; Sat, 12 Apr 2014 13:33:35 +0200 From: Christoph Jaeger To: clm@fb.com, jbacik@fb.com Cc: linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Jaeger Subject: [PATCH] btrfs: fix use-after-free in mount_subvol() Date: Sat, 12 Apr 2014 13:33:13 +0200 Message-Id: <1397302393-22145-1-git-send-email-christophjaeger@linux.com> X-Mailer: git-send-email 1.9.0 X-Df-Sender: MTg4NDM4Mw== 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 Pointer 'newargs' is used after the memory that it points to has already been freed. Picked up by Coverity - CID 1201425. Fixes: 0723a0473f ("btrfs: allow mounting btrfs subvolumes with different ro/rw options") Signed-off-by: Christoph Jaeger --- fs/btrfs/super.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 5011aad..62f70cc 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1186,7 +1186,6 @@ static struct dentry *mount_subvol(const char *subvol_name, int flags, return ERR_PTR(-ENOMEM); mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs); - kfree(newargs); if (PTR_RET(mnt) == -EBUSY) { if (flags & MS_RDONLY) { @@ -1196,17 +1195,22 @@ static struct dentry *mount_subvol(const char *subvol_name, int flags, int r; mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, device_name, newargs); - if (IS_ERR(mnt)) + if (IS_ERR(mnt)) { + kfree(newargs); return ERR_CAST(mnt); + } r = btrfs_remount(mnt->mnt_sb, &flags, NULL); if (r < 0) { /* FIXME: release vfsmount mnt ??*/ + kfree(newargs); return ERR_PTR(r); } } } + kfree(newargs); + if (IS_ERR(mnt)) return ERR_CAST(mnt);