[PATCH 5.18 182/339] netfilter: nf_tables: delete flowtable hooks via transaction list

From: Greg Kroah-Hartman
Date: Mon Jun 13 2022 - 09:52:18 EST


From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>

[ Upstream commit b6d9014a3335194590abdd2a2471ef5147a67645 ]

Remove inactive bool field in nft_hook object that was introduced in
abadb2f865d7 ("netfilter: nf_tables: delete devices from flowtable").
Move stale flowtable hooks to transaction list instead.

Deleting twice the same device does not result in ENOENT.

Fixes: abadb2f865d7 ("netfilter: nf_tables: delete devices from flowtable")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/net/netfilter/nf_tables.h | 1 -
net/netfilter/nf_tables_api.c | 31 ++++++-------------------------
2 files changed, 6 insertions(+), 26 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 20af9d3557b9..279ae0fff7ad 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -1090,7 +1090,6 @@ struct nft_stats {

struct nft_hook {
struct list_head list;
- bool inactive;
struct nf_hook_ops ops;
struct rcu_head rcu;
};
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index a0981e7cb211..f23c40e6caa6 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1914,7 +1914,6 @@ static struct nft_hook *nft_netdev_hook_alloc(struct net *net,
goto err_hook_dev;
}
hook->ops.dev = dev;
- hook->inactive = false;

return hook;

@@ -7612,6 +7611,7 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx,
{
const struct nlattr * const *nla = ctx->nla;
struct nft_flowtable_hook flowtable_hook;
+ LIST_HEAD(flowtable_del_list);
struct nft_hook *this, *hook;
struct nft_trans *trans;
int err;
@@ -7627,7 +7627,7 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx,
err = -ENOENT;
goto err_flowtable_del_hook;
}
- hook->inactive = true;
+ list_move(&hook->list, &flowtable_del_list);
}

trans = nft_trans_alloc(ctx, NFT_MSG_DELFLOWTABLE,
@@ -7640,6 +7640,7 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx,
nft_trans_flowtable(trans) = flowtable;
nft_trans_flowtable_update(trans) = true;
INIT_LIST_HEAD(&nft_trans_flowtable_hooks(trans));
+ list_splice(&flowtable_del_list, &nft_trans_flowtable_hooks(trans));
nft_flowtable_hook_release(&flowtable_hook);

nft_trans_commit_list_add_tail(ctx->net, trans);
@@ -7647,13 +7648,7 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx,
return 0;

err_flowtable_del_hook:
- list_for_each_entry(this, &flowtable_hook.list, list) {
- hook = nft_hook_list_find(&flowtable->hook_list, this);
- if (!hook)
- break;
-
- hook->inactive = false;
- }
+ list_splice(&flowtable_del_list, &flowtable->hook_list);
nft_flowtable_hook_release(&flowtable_hook);

return err;
@@ -8559,17 +8554,6 @@ void nft_chain_del(struct nft_chain *chain)
list_del_rcu(&chain->list);
}

-static void nft_flowtable_hooks_del(struct nft_flowtable *flowtable,
- struct list_head *hook_list)
-{
- struct nft_hook *hook, *next;
-
- list_for_each_entry_safe(hook, next, &flowtable->hook_list, list) {
- if (hook->inactive)
- list_move(&hook->list, hook_list);
- }
-}
-
static void nf_tables_module_autoload_cleanup(struct net *net)
{
struct nftables_pernet *nft_net = nft_pernet(net);
@@ -8914,8 +8898,6 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
break;
case NFT_MSG_DELFLOWTABLE:
if (nft_trans_flowtable_update(trans)) {
- nft_flowtable_hooks_del(nft_trans_flowtable(trans),
- &nft_trans_flowtable_hooks(trans));
nf_tables_flowtable_notify(&trans->ctx,
nft_trans_flowtable(trans),
&nft_trans_flowtable_hooks(trans),
@@ -8996,7 +8978,6 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
struct nftables_pernet *nft_net = nft_pernet(net);
struct nft_trans *trans, *next;
struct nft_trans_elem *te;
- struct nft_hook *hook;

if (action == NFNL_ABORT_VALIDATE &&
nf_tables_validate(net) < 0)
@@ -9127,8 +9108,8 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
break;
case NFT_MSG_DELFLOWTABLE:
if (nft_trans_flowtable_update(trans)) {
- list_for_each_entry(hook, &nft_trans_flowtable(trans)->hook_list, list)
- hook->inactive = false;
+ list_splice(&nft_trans_flowtable_hooks(trans),
+ &nft_trans_flowtable(trans)->hook_list);
} else {
trans->ctx.table->use++;
nft_clear(trans->ctx.net, nft_trans_flowtable(trans));
--
2.35.1