releases/4.4.160/ocfs2-fix-locking-for-res-tracking-and-dlm-tracking_list.patch

   1 From cbe355f57c8074bc4f452e5b6e35509044c6fa23 Mon Sep 17 00:00:00 2001
   2 From: Ashish Samant <ashish.samant@oracle.com>
   3 Date: Fri, 5 Oct 2018 15:52:15 -0700
   4 Subject: ocfs2: fix locking for res->tracking and dlm->tracking_list
   5
   6 From: Ashish Samant <ashish.samant@oracle.com>
   7
   8 commit cbe355f57c8074bc4f452e5b6e35509044c6fa23 upstream.
   9
  10 In dlm_init_lockres() we access and modify res->tracking and
  11 dlm->tracking_list without holding dlm->track_lock.  This can cause list
  12 corruptions and can end up in kernel panic.
  13
  14 Fix this by locking res->tracking and dlm->tracking_list with
  15 dlm->track_lock instead of dlm->spinlock.
  16
  17 Link: http://lkml.kernel.org/r/1529951192-4686-1-git-send-email-ashish.samant@oracle.com
  18 Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
  19 Reviewed-by: Changwei Ge <ge.changwei@h3c.com>
  20 Acked-by: Joseph Qi <jiangqi903@gmail.com>
  21 Acked-by: Jun Piao <piaojun@huawei.com>
  22 Cc: Mark Fasheh <mark@fasheh.com>
  23 Cc: Joel Becker <jlbec@evilplan.org>
  24 Cc: Junxiao Bi <junxiao.bi@oracle.com>
  25 Cc: Changwei Ge <ge.changwei@h3c.com>
  26 Cc: <stable@vger.kernel.org>
  27 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  28 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  29
  30 ---
  31  fs/ocfs2/dlm/dlmmaster.c |    4 ++--
  32  1 file changed, 2 insertions(+), 2 deletions(-)
  33
  34 --- a/fs/ocfs2/dlm/dlmmaster.c
  35 +++ b/fs/ocfs2/dlm/dlmmaster.c
  36 @@ -589,9 +589,9 @@ static void dlm_init_lockres(struct dlm_
  37
  38         res->last_used = 0;
  39
  40 -       spin_lock(&dlm->spinlock);
  41 +       spin_lock(&dlm->track_lock);
  42         list_add_tail(&res->tracking, &dlm->tracking_list);
  43 -       spin_unlock(&dlm->spinlock);
  44 +       spin_unlock(&dlm->track_lock);
  45
  46         memset(res->lvb, 0, DLM_LVB_LEN);
  47         memset(res->refmap, 0, sizeof(res->refmap));