net_sched: fix struct tc_u_hnode layout in u32
We dynamically allocate divisor+1 entries for ->ht[] in tc_u_hnode:
ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
So ->ht is supposed to be the last field of this struct, however
this is broken, since an rcu head is appended after it.
Fixes: 1ce87720d456 ("net: sched: make cls_u32 lockless")
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 09487af..95fdf4e 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -78,8 +78,11 @@
struct tc_u_common *tp_c;
int refcnt;
unsigned int divisor;
- struct tc_u_knode __rcu *ht[1];
struct rcu_head rcu;
+ /* The 'ht' field MUST be the last field in structure to allow for
+ * more entries allocated at end of structure.
+ */
+ struct tc_u_knode __rcu *ht[1];
};
struct tc_u_common {