From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:34253 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753304Ab1LWATW (ORCPT ); Thu, 22 Dec 2011 19:19:22 -0500 Date: Thu, 22 Dec 2011 19:19:21 -0500 To: linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH] locks: fix null dereference on lease-break failure path Message-ID: <20111223001921.GA8875@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii From: "J. Bruce Fields" Sender: linux-nfs-owner@vger.kernel.org List-ID: From: "J. Bruce Fields" Commit 778fc546f749c588aa2f6cd50215d2715c374252 "locks: fix tracking of inprogress lease breaks" introduced a null dereference on failure to allocate memory. This means an open (without O_NONBLOCK set) on a file with a lease applied (generally only done when Samba or nfsd (with v4) is running) could crash if a kmalloc() fails. Signed-off-by: J. Bruce Fields --- fs/locks.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) Eh, supposedly I'm on vacation till the end of the year, but I just noticed this.... I'll send it in for 3.2 soon if nobody notices a problem (and if I don't miss the release). diff --git a/fs/locks.c b/fs/locks.c index 3b0d05d..96a487a 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1214,8 +1214,8 @@ int __break_lease(struct inode *inode, unsigned int mode) if ((flock == NULL) || !IS_LEASE(flock)) goto out; - if (!locks_conflict(flock, new_fl)) - goto out; + if (flock->fl_type == F_RDLCK && !want_write) + goto out; /* no conflict */ for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) if (fl->fl_owner == current->files) -- 1.7.7.4