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Commit a35ad97c authored by Zhonghua Guo's avatar Zhonghua Guo Committed by Linus Torvalds
Browse files

ocfs2: fix deadlock risk when kmalloc failed in dlm_query_region_handler 



In dlm_query_region_handler(), once kmalloc failed, it will unlock
dlm_domain_lock without lock first, then deadlock happens.

Signed-off-by: default avatarZhonghua Guo <guozhonghua@h3c.com>
Signed-off-by: default avatarJoseph Qi <joseph.qi@huawei.com>
Reviewed-by: default avatarSrinivas Eeda <srinivas.eeda@oracle.com>
Tested-by: default avatarJoseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c8d888d9

fs/ocfs2/dlm/dlmdomain.c

+9 −12
Original line number Diff line number Diff line
@@ -1123,7 +1123,6 @@ static int dlm_query_region_handler(struct o2net_msg *msg, u32 len, 
	struct dlm_ctxt *dlm = NULL;

	char *local = NULL;

	int status = 0;

	int locked = 0;



	qr = (struct dlm_query_region *) msg->buf;
@@ -1132,10 +1131,8 @@ static int dlm_query_region_handler(struct o2net_msg *msg, u32 len, 


	/* buffer used in dlm_mast_regions() */

	local = kmalloc(sizeof(qr->qr_regions), GFP_KERNEL);

	if (!local) {

		status = -ENOMEM;

		goto bail;

	}

	if (!local)

		return -ENOMEM;



	status = -EINVAL;
@@ -1144,16 +1141,15 @@ static int dlm_query_region_handler(struct o2net_msg *msg, u32 len, 
	if (!dlm) {

		mlog(ML_ERROR, "Node %d queried hb regions on domain %s "

		     "before join domain\n", qr->qr_node, qr->qr_domain);

		goto bail;

		goto out_domain_lock;

	}



	spin_lock(&dlm->spinlock);

	locked = 1;

	if (dlm->joining_node != qr->qr_node) {

		mlog(ML_ERROR, "Node %d queried hb regions on domain %s "

		     "but joining node is %d\n", qr->qr_node, qr->qr_domain,

		     dlm->joining_node);

		goto bail;

		goto out_dlm_lock;

	}



	/* Support for global heartbeat was added in 1.1 */
@@ -1163,14 +1159,15 @@ static int dlm_query_region_handler(struct o2net_msg *msg, u32 len, 
		     "but active dlm protocol is %d.%d\n", qr->qr_node,

		     qr->qr_domain, dlm->dlm_locking_proto.pv_major,

		     dlm->dlm_locking_proto.pv_minor);

		goto bail;

		goto out_dlm_lock;

	}



	status = dlm_match_regions(dlm, qr, local, sizeof(qr->qr_regions));



bail:

	if (locked)

out_dlm_lock:

	spin_unlock(&dlm->spinlock);



out_domain_lock:

	spin_unlock(&dlm_domain_lock);



	kfree(local);