Patch "md-cluster: fix potential lock issue in add_new_disk" has been added to the 4.4-stable tree

Patch "md-cluster: fix potential lock issue in add_new_disk" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    md-cluster: fix potential lock issue in add_new_disk

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     md-cluster-fix-potential-lock-issue-in-add_new_disk.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Tue Apr 10 10:31:53 CEST 2018
From: Guoqing Jiang <gqjiang@suse.com>
Date: Tue, 16 May 2017 14:01:25 +0800
Subject: md-cluster: fix potential lock issue in add_new_disk

From: Guoqing Jiang <gqjiang@suse.com>


[ Upstream commit 2dffdc0724004f38f5e39907747b53e4b0d80e59 ]

The add_new_disk returns with communication locked if
__sendmsg returns failure, fix it with call unlock_comm
before return.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
CC: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/md/md-cluster.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -945,8 +945,10 @@ static int add_new_disk(struct mddev *md
 	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
 	lock_comm(cinfo);
 	ret = __sendmsg(cinfo, &cmsg);
-	if (ret)
+	if (ret) {
+		unlock_comm(cinfo);
 		return ret;
+	}
 	cinfo->no_new_dev_lockres->flags |= DLM_LKF_NOQUEUE;
 	ret = dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_EX);
 	cinfo->no_new_dev_lockres->flags &= ~DLM_LKF_NOQUEUE;


Patches currently in stable-queue which might be from gqjiang@suse.com are

queue-4.4/md-cluster-fix-potential-lock-issue-in-add_new_disk.patch