diff options
| author | Florian Westphal <fw@strlen.de> | 2018-06-11 14:20:35 +0300 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2018-06-12 20:28:18 +0300 |
| commit | 71ad00c50d77e507138c792a9646b53c16f22e11 (patch) | |
| tree | c1e02e45c573ae8003390fc95923e48cc70440b0 | |
| parent | 215a31f19dedd4e92a67cf5a9717ee898d012b3a (diff) | |
| download | linux-71ad00c50d77e507138c792a9646b53c16f22e11.tar.xz | |
netfilter: nf_tables: fix module unload race
We must first remove the nfnetlink protocol handler when nf_tables module
is unloaded -- we don't want userspace to submit new change requests once
we've started to tear down nft state.
Furthermore, nfnetlink must not call any subsystem function after
call_batch returned -EAGAIN.
EAGAIN means the subsys mutex was dropped, so its unlikely but possible that
nf_tables subsystem was removed due to 'rmmod nf_tables' on another cpu.
Therefore, we must abort batch completely and not move on to next part of
the batch.
Last, we can't invoke ->abort unless we've checked that the subsystem is
still registered.
Change netns exit path of nf_tables to make sure any incompleted
transaction gets removed on exit.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | net/netfilter/nf_tables_api.c | 12 | ||||
| -rw-r--r-- | net/netfilter/nfnetlink.c | 10 |
2 files changed, 16 insertions, 6 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 7979095b69b0..ae312b31db28 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -6439,7 +6439,7 @@ static void nf_tables_abort_release(struct nft_trans *trans) kfree(trans); } -static int nf_tables_abort(struct net *net, struct sk_buff *skb) +static int __nf_tables_abort(struct net *net) { struct nft_trans *trans, *next; struct nft_trans_elem *te; @@ -6555,6 +6555,11 @@ static void nf_tables_cleanup(struct net *net) nft_validate_state_update(net, NFT_VALIDATE_SKIP); } +static int nf_tables_abort(struct net *net, struct sk_buff *skb) +{ + return __nf_tables_abort(net); +} + static bool nf_tables_valid_genid(struct net *net, u32 genid) { return net->nft.base_seq == genid; @@ -7149,9 +7154,10 @@ static int __net_init nf_tables_init_net(struct net *net) static void __net_exit nf_tables_exit_net(struct net *net) { + if (!list_empty(&net->nft.commit_list)) + __nf_tables_abort(net); __nft_release_tables(net); WARN_ON_ONCE(!list_empty(&net->nft.tables)); - WARN_ON_ONCE(!list_empty(&net->nft.commit_list)); } static struct pernet_operations nf_tables_net_ops = { @@ -7193,9 +7199,9 @@ err1: static void __exit nf_tables_module_exit(void) { - unregister_pernet_subsys(&nf_tables_net_ops); nfnetlink_subsys_unregister(&nf_tables_subsys); unregister_netdevice_notifier(&nf_tables_flowtable_notifier); + unregister_pernet_subsys(&nf_tables_net_ops); rcu_barrier(); nf_tables_core_module_exit(); kfree(info); diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index 4d0da7042aff..e1b6be29848d 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -429,7 +429,7 @@ replay: */ if (err == -EAGAIN) { status |= NFNL_BATCH_REPLAY; - goto next; + goto done; } } ack: @@ -456,7 +456,7 @@ ack: if (err) status |= NFNL_BATCH_FAILURE; } -next: + msglen = NLMSG_ALIGN(nlh->nlmsg_len); if (msglen > skb->len) msglen = skb->len; @@ -464,7 +464,11 @@ next: } done: if (status & NFNL_BATCH_REPLAY) { - ss->abort(net, oskb); + const struct nfnetlink_subsystem *ss2; + + ss2 = nfnl_dereference_protected(subsys_id); + if (ss2 == ss) + ss->abort(net, oskb); nfnl_err_reset(&err_list); nfnl_unlock(subsys_id); kfree_skb(skb); |