[PATCH] sched/topology: fix potential memoryleak in sched_init_numa()

[Miaohe Lin]

When sched_init_numa() fails to allocate enough memory for sched domains
numa masks, it forgot to free the allocated memory leading to memoryleak.
Add a helper to help release the resource.

Fixes: cb83b629bae0 ("sched/numa: Rewrite the CONFIG_NUMA sched domain support")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
 kernel/sched/topology.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 290509383419..dcec4d653ae3 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1807,6 +1807,20 @@ static void init_numa_topology_type(int offline_node)
 
 #define NR_DISTANCE_VALUES (1 << DISTANCE_BITS)
 
+static void sched_free_numa_mask(struct cpumask ***masks, int nr_levels)
+{
+	int i, j;
+
+	for (i = 0; i < nr_levels; i++) {
+		if (!masks[i])
+			continue;
+		for_each_node(j)
+			kfree(masks[i][j]);
+		kfree(masks[i]);
+	}
+	kfree(masks);
+}
+
 void sched_init_numa(int offline_node)
 {
 	struct sched_domain_topology_level *tl;
@@ -1886,15 +1900,19 @@ void sched_init_numa(int offline_node)
 	 */
 	for (i = 0; i < nr_levels; i++) {
 		masks[i] = kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL);
-		if (!masks[i])
+		if (!masks[i]) {
+			sched_free_numa_mask(masks, nr_levels);
 			return;
+		}
 
 		for_each_cpu_node_but(j, offline_node) {
 			struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL);
 			int k;
 
-			if (!mask)
+			if (!mask) {
+				sched_free_numa_mask(masks, nr_levels);
 				return;
+			}
 
 			masks[i][j] = mask;
 
-- 
2.27.0