From d717bb2a9815f21ad962574daff821379f485ee3 Mon Sep 17 00:00:00 2001 From: Julian Anastasov Date: Wed, 17 Apr 2013 23:50:45 +0300 Subject: [PATCH] ipvs: properly dereference dest_dst in ip_vs_forget_dev Use rcu_dereference_protected to resolve sparse warning, found by kbuild test robot: net/netfilter/ipvs/ip_vs_ctl.c:1464:35: warning: dereference of noderef expression Problem from commit 026ace060dfe29 ("ipvs: optimize dst usage for real server") Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_ctl.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 9e4074c26dc2..5a6544475b3c 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -1460,8 +1460,11 @@ void ip_vs_service_net_cleanup(struct net *net) static inline void ip_vs_forget_dev(struct ip_vs_dest *dest, struct net_device *dev) { + struct ip_vs_dest_dst *dest_dst; + spin_lock_bh(&dest->dst_lock); - if (dest->dest_dst && dest->dest_dst->dst_cache->dev == dev) { + dest_dst = rcu_dereference_protected(dest->dest_dst, 1); + if (dest_dst && dest_dst->dst_cache->dev == dev) { IP_VS_DBG_BUF(3, "Reset dev:%s dest %s:%u ,dest->refcnt=%d\n", dev->name, IP_VS_DBG_ADDR(dest->af, &dest->addr),