net/sched: act_pedit: Use flex_array_size() helper in memcpy()

Make use of the flex_array_size() helper to calculate the size of a
flexible array member within an enclosing structure.

This helper offers defense-in-depth against potential integer
overflows, while at the same time makes it explicitly clear that
we are dealing with a flexible array member.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c
index 66986db..c158bfe 100644 (file)
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -436,8 +436,7 @@ static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
                return -ENOBUFS;
 
        spin_lock_bh(&p->tcf_lock);
-       memcpy(opt->keys, p->tcfp_keys,
-              p->tcfp_nkeys * sizeof(struct tc_pedit_key));
+       memcpy(opt->keys, p->tcfp_keys, flex_array_size(opt, keys, p->tcfp_nkeys));
        opt->index = p->tcf_index;
        opt->nkeys = p->tcfp_nkeys;
        opt->flags = p->tcfp_flags;