1 files changed, 30 insertions, 6 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index a8ab5e73dc61..69c4a0c92ebb 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1264,6 +1264,7 @@ static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
 		     unsigned long maxnode)
 {
 	unsigned long k;
+	unsigned long t;
 	unsigned long nlongs;
 	unsigned long endmask;
 
@@ -1280,13 +1281,19 @@ static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
 	else
 		endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
 
-	/* When the user specified more nodes than supported just check
-	   if the non supported part is all zero. */
+	/*
+	 * When the user specified more nodes than supported just check
+	 * if the non supported part is all zero.
+	 *
+	 * If maxnode have more longs than MAX_NUMNODES, check
+	 * the bits in that area first. And then go through to
+	 * check the rest bits which equal or bigger than MAX_NUMNODES.
+	 * Otherwise, just check bits [MAX_NUMNODES, maxnode).
+	 */
 	if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
 		if (nlongs > PAGE_SIZE/sizeof(long))
 			return -EINVAL;
 		for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
-			unsigned long t;
 			if (get_user(t, nmask + k))
 				return -EFAULT;
 			if (k == nlongs - 1) {
@@ -1299,6 +1306,16 @@ static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
 		endmask = ~0UL;
 	}
 
+	if (maxnode > MAX_NUMNODES && MAX_NUMNODES % BITS_PER_LONG != 0) {
+		unsigned long valid_mask = endmask;
+
+		valid_mask &= ~((1UL << (MAX_NUMNODES % BITS_PER_LONG)) - 1);
+		if (get_user(t, nmask + nlongs - 1))
+			return -EFAULT;
+		if (t & valid_mask)
+			return -EINVAL;
+	}
+
 	if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
 		return -EFAULT;
 	nodes_addr(*nodes)[nlongs-1] &= endmask;
@@ -1425,10 +1442,14 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
 		goto out_put;
 	}
 
-	if (!nodes_subset(*new, node_states[N_MEMORY])) {
-		err = -EINVAL;
+	task_nodes = cpuset_mems_allowed(current);
+	nodes_and(*new, *new, task_nodes);
+	if (nodes_empty(*new))
+		goto out_put;
+
+	nodes_and(*new, *new, node_states[N_MEMORY]);
+	if (nodes_empty(*new))
 		goto out_put;
-	}
 
 	err = security_task_movememory(task);
 	if (err)
@@ -2138,6 +2159,9 @@ bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
 	case MPOL_INTERLEAVE:
 		return !!nodes_equal(a->v.nodes, b->v.nodes);
 	case MPOL_PREFERRED:
+		/* a's ->flags is the same as b's */
+		if (a->flags & MPOL_F_LOCAL)
+			return true;
 		return a->v.preferred_node == b->v.preferred_node;
 	default:
 		BUG();