netfilter: nf_tables: release batch on table validation from abort path

Unlike early commit path stage which triggers a call to abort, an
explicit release of the batch is required on abort, otherwise mutex is
released and commit_list remains in place.

Add WARN_ON_ONCE to ensure commit_list is empty from the abort path
before releasing the mutex.

After this patch, commit_list is always assumed to be empty before
grabbing the mutex, therefore

  03c1f1ef1584 ("netfilter: Cleanup nft_net->module_list from nf_tables_exit_net()")

only needs to release the pending modules for registration.

Cc: stable@vger.kernel.org
Fixes: c0391b6ab810 ("netfilter: nf_tables: missing validation from the abort path")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index fd86f2720c9e776b08db64c6f1083a425c289754..ffcd3213c335854c28007d3f1de717444663d41b 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -10455,10 +10455,11 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
        struct nft_trans *trans, *next;
        LIST_HEAD(set_update_list);
        struct nft_trans_elem *te;
+       int err = 0;
 
        if (action == NFNL_ABORT_VALIDATE &&
            nf_tables_validate(net) < 0)
-               return -EAGAIN;
+               err = -EAGAIN;
 
        list_for_each_entry_safe_reverse(trans, next, &nft_net->commit_list,
                                         list) {
@@ -10655,7 +10656,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
        else
                nf_tables_module_autoload_cleanup(net);
 
-       return 0;
+       return err;
 }
 
 static int nf_tables_abort(struct net *net, struct sk_buff *skb,
@@ -10668,6 +10669,9 @@ static int nf_tables_abort(struct net *net, struct sk_buff *skb,
        gc_seq = nft_gc_seq_begin(nft_net);
        ret = __nf_tables_abort(net, action);
        nft_gc_seq_end(nft_net, gc_seq);
+
+       WARN_ON_ONCE(!list_empty(&nft_net->commit_list));
+
        mutex_unlock(&nft_net->commit_mutex);
 
        return ret;
@@ -11473,9 +11477,10 @@ static void __net_exit nf_tables_exit_net(struct net *net)
 
        gc_seq = nft_gc_seq_begin(nft_net);
 
-       if (!list_empty(&nft_net->commit_list) ||
-           !list_empty(&nft_net->module_list))
-               __nf_tables_abort(net, NFNL_ABORT_NONE);
+       WARN_ON_ONCE(!list_empty(&nft_net->commit_list));
+
+       if (!list_empty(&nft_net->module_list))
+               nf_tables_module_autoload_cleanup(net);
 
        __nft_release_tables(net);