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authorPablo Neira <pablo@netfilter.org>2015-10-13 12:47:48 +0200
committerPablo Neira Ayuso <pablo@netfilter.org>2015-10-15 06:45:03 +0200
commit8cbc870829ecd8f1062f2a756683c80e2d1eae7f (patch)
treea6aef860ba8faa818349f7033e574f4b060485ee
parent336a3b3ee925362ca720342bbae4f36b2215064a (diff)
netfilter: nfnetlink_log: validate dependencies to avoid breaking atomicity
Check that dependencies are fulfilled before updating the logger instance, otherwise we can leave things in intermediate state on errors in nfulnl_recv_config(). [ Ken-ichirou reports that this is also fixing missing instance refcnt drop on error introduced in his patch 914eebf2f434 ("netfilter: nfnetlink_log: autoload nf_conntrack_netlink module NFQA_CFG_F_CONNTRACK config flag"). ] Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Tested-by: Ken-ichirou MATSUZAWA <chamaken@gmail.com>
-rw-r--r--net/netfilter/nfnetlink_log.c43
1 files changed, 24 insertions, 19 deletions
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 2002d579c3ba..a5b9680a1821 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -825,6 +825,7 @@ nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
struct net *net = sock_net(ctnl);
struct nfnl_log_net *log = nfnl_log_pernet(net);
int ret = 0;
+ u16 flags;
if (nfula[NFULA_CFG_CMD]) {
u_int8_t pf = nfmsg->nfgen_family;
@@ -846,6 +847,28 @@ nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
goto out_put;
}
+ /* Check if we support these flags in first place, dependencies should
+ * be there too not to break atomicity.
+ */
+ if (nfula[NFULA_CFG_FLAGS]) {
+ flags = ntohs(nla_get_be16(nfula[NFULA_CFG_FLAGS]));
+
+ if ((flags & NFULNL_CFG_F_CONNTRACK) &&
+ !rcu_access_pointer(nfnl_ct_hook)) {
+#ifdef CONFIG_MODULES
+ nfnl_unlock(NFNL_SUBSYS_ULOG);
+ request_module("ip_conntrack_netlink");
+ nfnl_lock(NFNL_SUBSYS_ULOG);
+ if (rcu_access_pointer(nfnl_ct_hook)) {
+ ret = -EAGAIN;
+ goto out_put;
+ }
+#endif
+ ret = -EOPNOTSUPP;
+ goto out_put;
+ }
+ }
+
if (cmd != NULL) {
switch (cmd->command) {
case NFULNL_CFG_CMD_BIND:
@@ -905,26 +928,8 @@ nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
nfulnl_set_qthresh(inst, ntohl(qthresh));
}
- if (nfula[NFULA_CFG_FLAGS]) {
- u16 flags = ntohs(nla_get_be16(nfula[NFULA_CFG_FLAGS]));
-
- if (flags & NFULNL_CFG_F_CONNTRACK &&
- !rcu_access_pointer(nfnl_ct_hook)) {
-#ifdef CONFIG_MODULES
- nfnl_unlock(NFNL_SUBSYS_ULOG);
- request_module("ip_conntrack_netlink");
- nfnl_lock(NFNL_SUBSYS_ULOG);
- if (rcu_access_pointer(nfnl_ct_hook)) {
- ret = -EAGAIN;
- goto out;
- }
-#endif
- ret = -EOPNOTSUPP;
- goto out;
- }
-
+ if (nfula[NFULA_CFG_FLAGS])
nfulnl_set_flags(inst, flags);
- }
out_put:
instance_put(inst);