From cbe355f57c8074bc4f452e5b6e35509044c6fa23 Mon Sep 17 00:00:00 2001
From: Ashish Samant <ashish.samant@oracle.com>
Date: Fri, 5 Oct 2018 15:52:15 -0700
Subject: [PATCH] ocfs2: fix locking for res->tracking and dlm->tracking_list
Git-commit: cbe355f57c8074bc4f452e5b6e35509044c6fa23
Patch-mainline: v4.19-rc7
References: bsc#1117816

In dlm_init_lockres() we access and modify res->tracking and
dlm->tracking_list without holding dlm->track_lock.  This can cause list
corruptions and can end up in kernel panic.

Fix this by locking res->tracking and dlm->tracking_list with
dlm->track_lock instead of dlm->spinlock.

Link: http://lkml.kernel.org/r/1529951192-4686-1-git-send-email-ashish.samant@oracle.com
Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
Reviewed-by: Changwei Ge <ge.changwei@h3c.com>
Acked-by: Joseph Qi <jiangqi903@gmail.com>
Acked-by: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Jan Kara <jack@suse.cz>

---
 fs/ocfs2/dlm/dlmmaster.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index aaca0949fe53..826f0567ec43 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -584,9 +584,9 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
 
 	res->last_used = 0;
 
-	spin_lock(&dlm->spinlock);
+	spin_lock(&dlm->track_lock);
 	list_add_tail(&res->tracking, &dlm->tracking_list);
-	spin_unlock(&dlm->spinlock);
+	spin_unlock(&dlm->track_lock);
 
 	memset(res->lvb, 0, DLM_LVB_LEN);
 	memset(res->refmap, 0, sizeof(res->refmap));
-- 
2.16.4