From 5778d39d070b4ac5f889928175b7f2d53ae7504e Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Mon, 9 Mar 2015 17:03:40 -0700 Subject: [PATCH] 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 Cc: John Fastabend Signed-off-by: Cong Wang Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/cls_u32.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index 09487afbfd51..95fdf4e40051 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -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 { -- 2.30.2