From: Patrick McHardy Date: Mon, 12 Feb 2007 19:13:43 +0000 (-0800) Subject: [NETFILTER]: nf_conntrack: fix invalid conntrack statistics RCU assumption X-Git-Tag: v2.6.21-rc1~274^2~1^2~11 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=c0e912d7ed8999f87fa7f084928aac1266e251f3;p=linux-2.6-omap-h63xx.git [NETFILTER]: nf_conntrack: fix invalid conntrack statistics RCU assumption NF_CT_STAT_INC assumes rcu_read_lock in nf_hook_slow disables preemption as well, making it legal to use __get_cpu_var without disabling preemption manually. The assumption is not correct anymore with preemptable RCU, additionally we need to protect against softirqs when not holding nf_conntrack_lock. Add NF_CT_STAT_INC_ATOMIC macro, which disables local softirqs, and use where necessary. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h index 68ec27490c2..0e690e34c00 100644 --- a/include/net/netfilter/nf_conntrack.h +++ b/include/net/netfilter/nf_conntrack.h @@ -257,6 +257,12 @@ extern int nf_conntrack_max; DECLARE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); #define NF_CT_STAT_INC(count) (__get_cpu_var(nf_conntrack_stat).count++) +#define NF_CT_STAT_INC_ATOMIC(count) \ +do { \ + local_bh_disable(); \ + __get_cpu_var(nf_conntrack_stat).count++; \ + local_bh_enable(); \ +} while (0) /* no helper, no nat */ #define NF_CT_F_BASIC 0 diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c index a2353edf4eb..4b7be4bb4d0 100644 --- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c +++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c @@ -154,8 +154,8 @@ ipv6_prepare(struct sk_buff **pskb, unsigned int hooknum, unsigned int *dataoff, */ if ((protoff < 0) || (protoff > (*pskb)->len)) { DEBUGP("ip6_conntrack_core: can't find proto in pkt\n"); - NF_CT_STAT_INC(error); - NF_CT_STAT_INC(invalid); + NF_CT_STAT_INC_ATOMIC(error); + NF_CT_STAT_INC_ATOMIC(invalid); return -NF_ACCEPT; } diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 3deeb900263..d59640e2377 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -563,7 +563,7 @@ static int early_drop(struct list_head *chain) if (del_timer(&ct->timeout)) { death_by_timeout((unsigned long)ct); dropped = 1; - NF_CT_STAT_INC(early_drop); + NF_CT_STAT_INC_ATOMIC(early_drop); } nf_ct_put(ct); return dropped; @@ -821,7 +821,7 @@ nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) /* Previously seen (loopback or untracked)? Ignore. */ if ((*pskb)->nfct) { - NF_CT_STAT_INC(ignore); + NF_CT_STAT_INC_ATOMIC(ignore); return NF_ACCEPT; } @@ -840,8 +840,8 @@ nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) * core what to do with the packet. */ if (l4proto->error != NULL && (ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) { - NF_CT_STAT_INC(error); - NF_CT_STAT_INC(invalid); + NF_CT_STAT_INC_ATOMIC(error); + NF_CT_STAT_INC_ATOMIC(invalid); return -ret; } @@ -849,13 +849,13 @@ nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) &set_reply, &ctinfo); if (!ct) { /* Not valid part of a connection */ - NF_CT_STAT_INC(invalid); + NF_CT_STAT_INC_ATOMIC(invalid); return NF_ACCEPT; } if (IS_ERR(ct)) { /* Too stressed to deal. */ - NF_CT_STAT_INC(drop); + NF_CT_STAT_INC_ATOMIC(drop); return NF_DROP; } @@ -868,7 +868,7 @@ nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb) DEBUGP("nf_conntrack_in: Can't track with proto module\n"); nf_conntrack_put((*pskb)->nfct); (*pskb)->nfct = NULL; - NF_CT_STAT_INC(invalid); + NF_CT_STAT_INC_ATOMIC(invalid); return -ret; }