Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933388AbcCQJB0 (ORCPT ); Thu, 17 Mar 2016 05:01:26 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:33989 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932929AbcCQJA7 (ORCPT ); Thu, 17 Mar 2016 05:00:59 -0400 From: Miklos Szeredi To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: dhowells@redhat.com, viro@zeniv.linux.org.uk, Daniel Axtens , "Theodore Ts'o" , Subject: [PATCH 4/4] ext4: use file_dentry() Date: Thu, 17 Mar 2016 10:02:03 +0100 Message-Id: <1458205323-25685-4-git-send-email-miklos@szeredi.hu> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1458205323-25685-1-git-send-email-miklos@szeredi.hu> References: <1458205323-25685-1-git-send-email-miklos@szeredi.hu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1261 Lines: 35 From: Miklos Szeredi EXT4 may be used as lower layer of overlayfs and accessing f_path.dentry can lead to a crash. Fix by replacing direct access of file->f_path.dentry with the file_dentry() accessor, which will always return a native object. Reported-by: Daniel Axtens Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay") Fixes: ff978b09f973 ("ext4 crypto: move context consistency check to ext4_file_open()") Signed-off-by: Miklos Szeredi Cc: Theodore Ts'o Cc: David Howells Cc: Al Viro Cc: # v4.5 --- fs/ext4/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index feb9ffc6f20d..38847f38b34a 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -380,7 +380,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp) return -ENOKEY; } - dir = dget_parent(filp->f_path.dentry); + dir = dget_parent(file_dentry(filp)); if (ext4_encrypted_inode(d_inode(dir)) && !ext4_is_child_context_consistent_with_parent(d_inode(dir), inode)) { ext4_warning(inode->i_sb, -- 2.1.4