netfilter: nfnetlink_queue: validate dependencies to avoid breaking atomicity

Check that dependencies are fulfilled before updating the queue
instance, otherwise we can leave things in intermediate state on errors
in nfqnl_recv_config().

Signed-off-by: Ken-ichirou MATSUZAWA <chamas@h4.dion.ne.jp>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Ken-ichirou MATSUZAWA 2016-01-05 09:28:05 +09:00 committed by Pablo Neira Ayuso
parent ad6d950393
commit 60d2c7f9ab
1 changed files with 33 additions and 41 deletions

View File

@ -1113,6 +1113,7 @@ static int nfqnl_recv_config(struct net *net, struct sock *ctnl,
struct nfqnl_instance *queue;
struct nfqnl_msg_config_cmd *cmd = NULL;
struct nfnl_queue_net *q = nfnl_queue_pernet(net);
__u32 flags = 0, mask = 0;
int ret = 0;
if (nfqa[NFQA_CFG_CMD]) {
@ -1125,6 +1126,29 @@ static int nfqnl_recv_config(struct net *net, struct sock *ctnl,
}
}
/* Check if we support these flags in first place, dependencies should
* be there too not to break atomicity.
*/
if (nfqa[NFQA_CFG_FLAGS]) {
if (!nfqa[NFQA_CFG_MASK]) {
/* A mask is needed to specify which flags are being
* changed.
*/
return -EINVAL;
}
flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
if (flags >= NFQA_CFG_F_MAX)
return -EOPNOTSUPP;
#if !IS_ENABLED(CONFIG_NETWORK_SECMARK)
if (flags & mask & NFQA_CFG_F_SECCTX)
return -EOPNOTSUPP;
#endif
}
rcu_read_lock();
queue = instance_lookup(q, queue_num);
if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
@ -1162,60 +1186,28 @@ static int nfqnl_recv_config(struct net *net, struct sock *ctnl,
}
}
if (nfqa[NFQA_CFG_PARAMS]) {
struct nfqnl_msg_config_params *params;
if (!queue) {
ret = -ENODEV;
goto err_out_unlock;
}
if (nfqa[NFQA_CFG_PARAMS]) {
struct nfqnl_msg_config_params *params =
nla_data(nfqa[NFQA_CFG_PARAMS]);
if (!queue) {
ret = -ENODEV;
goto err_out_unlock;
}
params = nla_data(nfqa[NFQA_CFG_PARAMS]);
nfqnl_set_mode(queue, params->copy_mode,
ntohl(params->copy_range));
}
if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
__be32 *queue_maxlen;
__be32 *queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
if (!queue) {
ret = -ENODEV;
goto err_out_unlock;
}
queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
spin_lock_bh(&queue->lock);
queue->queue_maxlen = ntohl(*queue_maxlen);
spin_unlock_bh(&queue->lock);
}
if (nfqa[NFQA_CFG_FLAGS]) {
__u32 flags, mask;
if (!queue) {
ret = -ENODEV;
goto err_out_unlock;
}
if (!nfqa[NFQA_CFG_MASK]) {
/* A mask is needed to specify which flags are being
* changed.
*/
ret = -EINVAL;
goto err_out_unlock;
}
flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
if (flags >= NFQA_CFG_F_MAX) {
ret = -EOPNOTSUPP;
goto err_out_unlock;
}
#if !IS_ENABLED(CONFIG_NETWORK_SECMARK)
if (flags & mask & NFQA_CFG_F_SECCTX) {
ret = -EOPNOTSUPP;
goto err_out_unlock;
}
#endif
spin_lock_bh(&queue->lock);
queue->flags &= ~mask;
queue->flags |= flags & mask;