diff options
| author | Patrick McHardy <kaber@trash.net> | 2008-11-25 00:56:17 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-11-25 00:56:17 +0100 |
| commit | b54ad409fd09a395b839fb81f300880d76861c0e (patch) | |
| tree | 580b23b89c04c85ad9795b37f81174e1bbb5311b /net/netfilter | |
| parent | drivers/net/chelsio/sge.c: remove redundant argument comments (diff) | |
| download | linux-b54ad409fd09a395b839fb81f300880d76861c0e.tar.xz linux-b54ad409fd09a395b839fb81f300880d76861c0e.zip | |
netfilter: ctnetlink: fix conntrack creation race
Conntrack creation through ctnetlink has two races:
- the timer may expire and free the conntrack concurrently, causing an
invalid memory access when attempting to put it in the hash tables
- an identical conntrack entry may be created in the packet processing
path in the time between the lookup and hash insertion
Hold the conntrack lock between the lookup and insertion to avoid this.
Reported-by: Zoltan Borbely <bozo@andrews.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netfilter')
| -rw-r--r-- | net/netfilter/nf_conntrack_core.c | 2 | ||||
| -rw-r--r-- | net/netfilter/nf_conntrack_netlink.c | 5 |
2 files changed, 3 insertions, 4 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 622d7c671cb7..233fdd2d7d21 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -305,9 +305,7 @@ void nf_conntrack_hash_insert(struct nf_conn *ct) hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple); - spin_lock_bh(&nf_conntrack_lock); __nf_conntrack_hash_insert(ct, hash, repl_hash); - spin_unlock_bh(&nf_conntrack_lock); } EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert); diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index a040d46f85d6..3b009a3e8549 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -1090,7 +1090,7 @@ ctnetlink_create_conntrack(struct nlattr *cda[], struct nf_conn_help *help; struct nf_conntrack_helper *helper; - ct = nf_conntrack_alloc(&init_net, otuple, rtuple, GFP_KERNEL); + ct = nf_conntrack_alloc(&init_net, otuple, rtuple, GFP_ATOMIC); if (ct == NULL || IS_ERR(ct)) return -ENOMEM; @@ -1212,13 +1212,14 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb, atomic_inc(&master_ct->ct_general.use); } - spin_unlock_bh(&nf_conntrack_lock); err = -ENOENT; if (nlh->nlmsg_flags & NLM_F_CREATE) err = ctnetlink_create_conntrack(cda, &otuple, &rtuple, master_ct); + spin_unlock_bh(&nf_conntrack_lock); + if (err < 0 && master_ct) nf_ct_put(master_ct); |