diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index e2d13cd18875..d8d33ef52ce0 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -506,9 +506,45 @@ static int ctnetlink_dump_use(struct sk_buff *skb, const struct nf_conn *ct) return -1; } +/* all these functions access ct->ext. Caller must either hold a reference + * on ct or prevent its deletion by holding either the bucket spinlock or + * pcpu dying list lock. + */ +static int ctnetlink_dump_extinfo(struct sk_buff *skb, + struct nf_conn *ct, u32 type) +{ + if (ctnetlink_dump_acct(skb, ct, type) < 0 || + ctnetlink_dump_timestamp(skb, ct) < 0 || + ctnetlink_dump_helpinfo(skb, ct) < 0 || + ctnetlink_dump_labels(skb, ct) < 0 || + ctnetlink_dump_ct_seq_adj(skb, ct) < 0 || + ctnetlink_dump_ct_synproxy(skb, ct) < 0) + return -1; + + return 0; +} + +static int ctnetlink_dump_info(struct sk_buff *skb, struct nf_conn *ct) +{ + if (ctnetlink_dump_status(skb, ct) < 0 || + ctnetlink_dump_mark(skb, ct) < 0 || + ctnetlink_dump_secctx(skb, ct) < 0 || + ctnetlink_dump_id(skb, ct) < 0 || + ctnetlink_dump_use(skb, ct) < 0 || + ctnetlink_dump_master(skb, ct) < 0) + return -1; + + if (!test_bit(IPS_OFFLOAD_BIT, &ct->status) && + (ctnetlink_dump_timeout(skb, ct) < 0 || + ctnetlink_dump_protoinfo(skb, ct) < 0)) + return -1; + + return 0; +} + static int ctnetlink_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, - struct nf_conn *ct) + struct nf_conn *ct, bool extinfo) { const struct nf_conntrack_zone *zone; struct nlmsghdr *nlh; @@ -552,23 +588,9 @@ ctnetlink_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, NF_CT_DEFAULT_ZONE_DIR) < 0) goto nla_put_failure; - if (ctnetlink_dump_status(skb, ct) < 0 || - ctnetlink_dump_acct(skb, ct, type) < 0 || - ctnetlink_dump_timestamp(skb, ct) < 0 || - ctnetlink_dump_helpinfo(skb, ct) < 0 || - ctnetlink_dump_mark(skb, ct) < 0 || - ctnetlink_dump_secctx(skb, ct) < 0 || - ctnetlink_dump_labels(skb, ct) < 0 || - ctnetlink_dump_id(skb, ct) < 0 || - ctnetlink_dump_use(skb, ct) < 0 || - ctnetlink_dump_master(skb, ct) < 0 || - ctnetlink_dump_ct_seq_adj(skb, ct) < 0 || - ctnetlink_dump_ct_synproxy(skb, ct) < 0) + if (ctnetlink_dump_info(skb, ct) < 0) goto nla_put_failure; - - if (!test_bit(IPS_OFFLOAD_BIT, &ct->status) && - (ctnetlink_dump_timeout(skb, ct) < 0 || - ctnetlink_dump_protoinfo(skb, ct) < 0)) + if (extinfo && ctnetlink_dump_extinfo(skb, ct, type) < 0) goto nla_put_failure; nlmsg_end(skb, nlh); @@ -953,13 +975,11 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb) if (!ctnetlink_filter_match(ct, cb->data)) continue; - rcu_read_lock(); res = ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NFNL_MSG_TYPE(cb->nlh->nlmsg_type), - ct); - rcu_read_unlock(); + ct, true); if (res < 0) { nf_conntrack_get(&ct->ct_general); cb->args[1] = (unsigned long)ct; @@ -1364,10 +1384,8 @@ static int ctnetlink_get_conntrack(struct net *net, struct sock *ctnl, return -ENOMEM; } - rcu_read_lock(); err = ctnetlink_fill_info(skb2, NETLINK_CB(skb).portid, nlh->nlmsg_seq, - NFNL_MSG_TYPE(nlh->nlmsg_type), ct); - rcu_read_unlock(); + NFNL_MSG_TYPE(nlh->nlmsg_type), ct, true); nf_ct_put(ct); if (err <= 0) goto free; @@ -1429,12 +1447,18 @@ ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying continue; cb->args[1] = 0; } - rcu_read_lock(); + + /* We can't dump extension info for the unconfirmed + * list because unconfirmed conntracks can have + * ct->ext reallocated (and thus freed). + * + * In the dying list case ct->ext can't be free'd + * until after we drop pcpu->lock. + */ res = ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NFNL_MSG_TYPE(cb->nlh->nlmsg_type), - ct); - rcu_read_unlock(); + ct, dying ? true : false); if (res < 0) { if (!atomic_inc_not_zero(&ct->ct_general.use)) continue;