From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755204AbbA0PBb (ORCPT ); Tue, 27 Jan 2015 10:01:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44369 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753936AbbA0PB2 (ORCPT ); Tue, 27 Jan 2015 10:01:28 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH] Infiniband: Fix potential NULL d_inode dereference From: David Howells Cc: infinipath@intel.com, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, dhowells@redhat.com, "Bryan O'Sullivan" , viro@zeniv.linux.org.uk, Roland Dreier Date: Tue, 27 Jan 2015 15:01:18 +0000 Message-ID: <20150127150118.24110.99894.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Code that does this: if (!(d_unhashed(tmp) && tmp->d_inode)) { ... simple_unlink(parent->d_inode, tmp); } is broken because: !(d_unhashed(tmp) && tmp->d_inode) is equivalent to: !d_unhashed(tmp) || !tmp->d_inode so it is possible to get into simple_unlink() with tmp->d_inode == NULL. simple_unlink(), however, assumes tmp->d_inode cannot be NULL. I think that what was meant is this: !d_unhashed(tmp) && tmp->d_inode and that the logical-not operator or the final close-bracket was misplaced. Signed-off-by: David Howells cc: Bryan O'Sullivan cc: Roland Dreier --- drivers/infiniband/hw/ipath/ipath_fs.c | 2 +- drivers/infiniband/hw/qib/qib_fs.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c index 4977082e081f..33c45dfcbd88 100644 --- a/drivers/infiniband/hw/ipath/ipath_fs.c +++ b/drivers/infiniband/hw/ipath/ipath_fs.c @@ -277,7 +277,7 @@ static int remove_file(struct dentry *parent, char *name) } spin_lock(&tmp->d_lock); - if (!(d_unhashed(tmp) && tmp->d_inode)) { + if (!d_unhashed(tmp) && tmp->d_inode) { dget_dlock(tmp); __d_drop(tmp); spin_unlock(&tmp->d_lock); diff --git a/drivers/infiniband/hw/qib/qib_fs.c b/drivers/infiniband/hw/qib/qib_fs.c index 81854586c081..d2427640d7e9 100644 --- a/drivers/infiniband/hw/qib/qib_fs.c +++ b/drivers/infiniband/hw/qib/qib_fs.c @@ -455,7 +455,7 @@ static int remove_file(struct dentry *parent, char *name) } spin_lock(&tmp->d_lock); - if (!(d_unhashed(tmp) && tmp->d_inode)) { + if (!d_unhashed(tmp) && tmp->d_inode) { __d_drop(tmp); spin_unlock(&tmp->d_lock); simple_unlink(parent->d_inode, tmp);