From 06b2c3b08ce134c9555d91a1cf15cd03646cc287 Mon Sep 17 00:00:00 2001 From: Wang Weiyang Date: Fri, 14 Jan 2022 14:05:42 -0800 Subject: [PATCH] mm/memcg: use struct_size() helper in kzalloc() 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 worst scenario, could lead to heap overflows. Link: https://github.com/KSPP/linux/issues/160 Link: https://lkml.kernel.org/r/20211216022024.127375-1-wangweiyang2@huawei.com Signed-off-by: Wang Weiyang Reviewed-by: Muchun Song Acked-by: Johannes Weiner Cc: Michal Hocko Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index aa2a152986367..88e1be912aa78 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5122,15 +5122,11 @@ static void mem_cgroup_free(struct mem_cgroup *memcg) static struct mem_cgroup *mem_cgroup_alloc(void) { struct mem_cgroup *memcg; - unsigned int size; int node; int __maybe_unused i; long error = -ENOMEM; - size = sizeof(struct mem_cgroup); - size += nr_node_ids * sizeof(struct mem_cgroup_per_node *); - - memcg = kzalloc(size, GFP_KERNEL); + memcg = kzalloc(struct_size(memcg, nodeinfo, nr_node_ids), GFP_KERNEL); if (!memcg) return ERR_PTR(error);