diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 0e884fe..9759bd7 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -142,6 +142,22 @@ static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb) return skb->nf_bridge; } +static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb) +{ + struct nf_bridge_info *nf_bridge = skb->nf_bridge; + + if (atomic_read(&nf_bridge->use) > 1) { + struct nf_bridge_info *tmp = nf_bridge_alloc(skb); + + if (tmp) { + memcpy(tmp, nf_bridge, sizeof(struct nf_bridge_info)); + nf_bridge_put(nf_bridge); + } + nf_bridge = tmp; + } + return nf_bridge; +} + static inline void nf_bridge_push_encap_header(struct sk_buff *skb) { unsigned int len = nf_bridge_encap_header_len(skb); @@ -637,6 +653,11 @@ static unsigned int br_nf_forward_ip(unsigned int hook, struct sk_buff *skb, if (!skb->nf_bridge) return NF_ACCEPT; + /* Need exclusive nf_bridge_info since we might have multiple + * different physoutdevs. */ + if (!nf_bridge_unshare(skb)) + return NF_DROP; + parent = bridge_parent(out); if (!parent) return NF_DROP; @@ -718,6 +739,11 @@ static unsigned int br_nf_local_out(unsigned int hook, struct sk_buff *skb, if (!skb->nf_bridge) return NF_ACCEPT; + /* Need exclusive nf_bridge_info since we might have multiple + * different physoutdevs. */ + if (!nf_bridge_unshare(skb)) + return NF_DROP; + nf_bridge = skb->nf_bridge; if (!(nf_bridge->mask & BRNF_BRIDGED_DNAT)) return NF_ACCEPT;