Messages in this thread Patch in this message | | | Date | Wed, 12 Dec 2007 22:53:53 -0800 | From | Greg KH <> | Subject | [patch 59/60] BRIDGE: Properly dereference the br_should_route_hook |
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2.6.23-stable review patch. If anyone has any objections, please let us know.
------------------ From: Pavel Emelyanov <xemul@openvz.org>
[BRIDGE]: Properly dereference the br_should_route_hook
[ Upstream commit: 82de382ce8e1c7645984616728dc7aaa057821e4 ]
This hook is protected with the RCU, so simple
if (br_should_route_hook) br_should_route_hook(...)
is not enough on some architectures.
Use the rcu_dereference/rcu_assign_pointer in this case.
Fixed Stephen's comment concerning using the typeof().
Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- net/bridge/br_input.c | 7 ++++--- net/bridge/netfilter/ebtable_broute.c | 4 ++-- 2 files changed, 6 insertions(+), 5 deletions(-)
--- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -122,6 +122,7 @@ static inline int is_link_local(const un struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb) { const unsigned char *dest = eth_hdr(skb)->h_dest; + int (*rhook)(struct sk_buff **pskb); if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) goto drop; @@ -143,9 +144,9 @@ struct sk_buff *br_handle_frame(struct n switch (p->state) { case BR_STATE_FORWARDING: - - if (br_should_route_hook) { - if (br_should_route_hook(&skb)) + rhook = rcu_dereference(br_should_route_hook); + if (rhook != NULL) { + if (rhook(&skb)) return skb; dest = eth_hdr(skb)->h_dest; } --- a/net/bridge/netfilter/ebtable_broute.c +++ b/net/bridge/netfilter/ebtable_broute.c @@ -70,13 +70,13 @@ static int __init ebtable_broute_init(vo if (ret < 0) return ret; /* see br_input.c */ - br_should_route_hook = ebt_broute; + rcu_assign_pointer(br_should_route_hook, ebt_broute); return ret; } static void __exit ebtable_broute_fini(void) { - br_should_route_hook = NULL; + rcu_assign_pointer(br_should_route_hook, NULL); synchronize_net(); ebt_unregister_table(&broute_table); } --
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