mm/mempolicy: Fix an incorrect rebind node in mpol_rebind_nodemask

euler inclusion
category: bugfix
bugzilla: 16085
CVE: NA

-------------------------------------------------

Commit 213980c0 ("mm, mempolicy: simplify rebinding mempolicies when updating cpusets")
introduce an numa bind issue. when set the cpuset.mem_allowed,
A process will rebind the specified policy more than one times.
if the cpuset_mems_allowed is not equal to user specified nodes. it will
result in the wrong policy which allocating much memory from wrong node.

Fixes: 213980c0 ("mm, mempolicy: simplify rebinding mempolicies when updating cpusets")
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Reviewed-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

mm/mempolicy.c

@@ -345,7 +345,7 @@ static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
 	else {
 		nodes_remap(tmp, pol->v.nodes,pol->w.cpuset_mems_allowed,
 								*nodes);
-		pol->w.cpuset_mems_allowed = tmp;
+		pol->w.cpuset_mems_allowed = *nodes;
 	}
 
 	if (nodes_empty(tmp))