From fe72926b792e52ab00abfa81a201805bfb2247d6 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 21 Sep 2016 11:35:02 -0400 Subject: [PATCH] netfilter: call nf_hook_state_init with rcu_read_lock held This makes things simpler because we can store the head of the list in the nf_state structure without worrying about concurrent add/delete of hook elements from the list. A future commit will make use of this to implement a simpler linked-list. Signed-off-by: Florian Westphal Signed-off-by: Aaron Conole Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter.h | 8 +++++++- include/linux/netfilter_ingress.h | 1 + 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index 9230f9aee896..ad444f0b4ed0 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -174,10 +174,16 @@ static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook, if (!list_empty(hook_list)) { struct nf_hook_state state; + int ret; + /* We may already have this, but read-locks nest anyway */ + rcu_read_lock(); nf_hook_state_init(&state, hook_list, hook, thresh, pf, indev, outdev, sk, net, okfn); - return nf_hook_slow(skb, &state); + + ret = nf_hook_slow(skb, &state); + rcu_read_unlock(); + return ret; } return 1; } diff --git a/include/linux/netfilter_ingress.h b/include/linux/netfilter_ingress.h index 5fcd375ef175..6965ba09eba7 100644 --- a/include/linux/netfilter_ingress.h +++ b/include/linux/netfilter_ingress.h @@ -14,6 +14,7 @@ static inline bool nf_hook_ingress_active(const struct sk_buff *skb) return !list_empty(&skb->dev->nf_hooks_ingress); } +/* caller must hold rcu_read_lock */ static inline int nf_hook_ingress(struct sk_buff *skb) { struct nf_hook_state state; -- 2.30.2