Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033553AbbKFUDt (ORCPT ); Fri, 6 Nov 2015 15:03:49 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:47774 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161863AbbKFTcY (ORCPT ); Fri, 6 Nov 2015 14:32:24 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ulrich Obergfell , David Howells , Miklos Szeredi Subject: [PATCH 4.1 62/86] ovl: fix dentry reference leak Date: Fri, 6 Nov 2015 11:23:01 -0800 Message-Id: <20151106192208.424627385@linuxfoundation.org> X-Mailer: git-send-email 2.6.2 In-Reply-To: <20151106192205.351595349@linuxfoundation.org> References: <20151106192205.351595349@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1895 Lines: 58 4.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Howells commit ab79efab0a0ba01a74df782eb7fa44b044dae8b5 upstream. In ovl_copy_up_locked(), newdentry is leaked if the function exits through out_cleanup as this just to out after calling ovl_cleanup() - which doesn't actually release the ref on newdentry. The out_cleanup segment should instead exit through out2 as certainly newdentry leaks - and possibly upper does also, though this isn't caught given the catch of newdentry. Without this fix, something like the following is seen: BUG: Dentry ffff880023e9eb20{i=f861,n=#ffff880023e82d90} still in use (1) [unmount of tmpfs tmpfs] BUG: Dentry ffff880023ece640{i=0,n=bigfile} still in use (1) [unmount of tmpfs tmpfs] when unmounting the upper layer after an error occurred in copyup. An error can be induced by creating a big file in a lower layer with something like: dd if=/dev/zero of=/lower/a/bigfile bs=65536 count=1 seek=$((0xf000)) to create a large file (4.1G). Overlay an upper layer that is too small (on tmpfs might do) and then induce a copy up by opening it writably. Reported-by: Ulrich Obergfell Signed-off-by: David Howells Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/copy_up.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -267,7 +267,7 @@ out: out_cleanup: ovl_cleanup(wdir, newdentry); - goto out; + goto out2; } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/