[PATCH -next, v3] sched: Use struct_size() helper in task_numa_group()

[Xiu Jianfeng]

Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows that,
in the worse scenario, could lead to heap overflows.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Xiu Jianfeng <xiujianfeng@xxxxxxxxxx>
---
 kernel/sched/fair.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 095b0aa378df..1a21bb33a4b2 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2437,9 +2437,8 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags,
 	int i;
 
 	if (unlikely(!deref_curr_numa_group(p))) {
-		unsigned int size = sizeof(struct numa_group) +
-				    NR_NUMA_HINT_FAULT_STATS *
-				    nr_node_ids * sizeof(unsigned long);
+		size_t size = struct_size(grp, faults,
+					  NR_NUMA_HINT_FAULT_STATS * nr_node_ids);
 
 		grp = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
 		if (!grp)
-- 
2.17.1