From d205dc40798d97d63ad348bfaf7394f445d152d4 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Thu, 17 Aug 2006 18:12:38 -0700 Subject: [PATCH] [NETFILTER]: ctnetlink: fix deadlock in table dumping ip_conntrack_put must not be called while holding ip_conntrack_lock since destroy_conntrack takes it again. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/ipv4/netfilter/ip_conntrack_netlink.c | 17 +++++++---------- net/netfilter/nf_conntrack_netlink.c | 17 +++++++---------- 2 files changed, 14 insertions(+), 20 deletions(-) diff --git a/net/ipv4/netfilter/ip_conntrack_netlink.c b/net/ipv4/netfilter/ip_conntrack_netlink.c index 33891bb1fd..0d4cc92391 100644 --- a/net/ipv4/netfilter/ip_conntrack_netlink.c +++ b/net/ipv4/netfilter/ip_conntrack_netlink.c @@ -415,21 +415,18 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb) cb->args[0], *id); read_lock_bh(&ip_conntrack_lock); + last = (struct ip_conntrack *)cb->args[1]; for (; cb->args[0] < ip_conntrack_htable_size; cb->args[0]++) { restart: - last = (struct ip_conntrack *)cb->args[1]; list_for_each_prev(i, &ip_conntrack_hash[cb->args[0]]) { h = (struct ip_conntrack_tuple_hash *) i; if (DIRECTION(h) != IP_CT_DIR_ORIGINAL) continue; ct = tuplehash_to_ctrack(h); - if (last != NULL) { - if (ct == last) { - ip_conntrack_put(last); - cb->args[1] = 0; - last = NULL; - } else + if (cb->args[1]) { + if (ct != last) continue; + cb->args[1] = 0; } if (ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, @@ -440,17 +437,17 @@ restart: goto out; } } - if (last != NULL) { - ip_conntrack_put(last); + if (cb->args[1]) { cb->args[1] = 0; goto restart; } } out: read_unlock_bh(&ip_conntrack_lock); + if (last) + ip_conntrack_put(last); DEBUGP("leaving, last bucket=%lu id=%u\n", cb->args[0], *id); - return skb->len; } diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index af4845971f..6527d4e048 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -429,9 +429,9 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb) cb->args[0], *id); read_lock_bh(&nf_conntrack_lock); + last = (struct nf_conn *)cb->args[1]; for (; cb->args[0] < nf_conntrack_htable_size; cb->args[0]++) { restart: - last = (struct nf_conn *)cb->args[1]; list_for_each_prev(i, &nf_conntrack_hash[cb->args[0]]) { h = (struct nf_conntrack_tuple_hash *) i; if (DIRECTION(h) != IP_CT_DIR_ORIGINAL) @@ -442,13 +442,10 @@ restart: * then dump everything. */ if (l3proto && L3PROTO(ct) != l3proto) continue; - if (last != NULL) { - if (ct == last) { - nf_ct_put(last); - cb->args[1] = 0; - last = NULL; - } else + if (cb->args[1]) { + if (ct != last) continue; + cb->args[1] = 0; } if (ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, @@ -459,17 +456,17 @@ restart: goto out; } } - if (last != NULL) { - nf_ct_put(last); + if (cb->args[1]) { cb->args[1] = 0; goto restart; } } out: read_unlock_bh(&nf_conntrack_lock); + if (last) + nf_ct_put(last); DEBUGP("leaving, last bucket=%lu id=%u\n", cb->args[0], *id); - return skb->len; } -- 2.39.5