Commit 5778d39d authored Mar 09, 2015 by WANG Cong Committed by David S. Miller Mar 09, 2015

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: 1ce87720 ("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>

parent affb8172

net/sched/cls_u32.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -78,8 +78,11 @@ struct tc_u_hnode {
		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 {

Admin message