Merge tag 'nf-24-04-04' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
Patch #1 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.
Patch #2 release mutex after nft_gc_seq_end() in commit path, otherwise
async GC worker could collect expired objects.
Patch #3 flush pending destroy work in module removal path, otherwise UaF
is possible.
Patch #4 and #6 restrict the table dormant flag with basechain updates
to fix state inconsistency in the hook registration.
Patch #5 adds missing RCU read side lock to flowtable type to avoid races
with module removal.
* tag 'nf-24-04-04' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nf_tables: discard table flag update with pending basechain deletion
netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get()
netfilter: nf_tables: reject new basechain after table flag update
netfilter: nf_tables: flush pending destroy work before exit_net release
netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path
netfilter: nf_tables: release batch on table validation from abort path
====================
Link: https://lore.kernel.org/r/20240404104334.1627-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index fd86f27..d89d7794 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1209,10 +1209,11 @@ static bool nft_table_pending_update(const struct nft_ctx *ctx)
return true;
list_for_each_entry(trans, &nft_net->commit_list, list) {
- if ((trans->msg_type == NFT_MSG_NEWCHAIN ||
- trans->msg_type == NFT_MSG_DELCHAIN) &&
- trans->ctx.table == ctx->table &&
- nft_trans_chain_update(trans))
+ if (trans->ctx.table == ctx->table &&
+ ((trans->msg_type == NFT_MSG_NEWCHAIN &&
+ nft_trans_chain_update(trans)) ||
+ (trans->msg_type == NFT_MSG_DELCHAIN &&
+ nft_is_base_chain(trans->ctx.chain))))
return true;
}
@@ -2449,6 +2450,9 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
struct nft_stats __percpu *stats = NULL;
struct nft_chain_hook hook = {};
+ if (table->flags & __NFT_TABLE_F_UPDATE)
+ return -EINVAL;
+
if (flags & NFT_CHAIN_BINDING)
return -EOPNOTSUPP;
@@ -8293,11 +8297,12 @@ static int nft_flowtable_parse_hook(const struct nft_ctx *ctx,
return err;
}
+/* call under rcu_read_lock */
static const struct nf_flowtable_type *__nft_flowtable_type_get(u8 family)
{
const struct nf_flowtable_type *type;
- list_for_each_entry(type, &nf_tables_flowtables, list) {
+ list_for_each_entry_rcu(type, &nf_tables_flowtables, list) {
if (family == type->family)
return type;
}
@@ -8309,9 +8314,13 @@ nft_flowtable_type_get(struct net *net, u8 family)
{
const struct nf_flowtable_type *type;
+ rcu_read_lock();
type = __nft_flowtable_type_get(family);
- if (type != NULL && try_module_get(type->owner))
+ if (type != NULL && try_module_get(type->owner)) {
+ rcu_read_unlock();
return type;
+ }
+ rcu_read_unlock();
lockdep_nfnl_nft_mutex_not_held();
#ifdef CONFIG_MODULES
@@ -10455,10 +10464,11 @@ 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) {
@@ -10650,12 +10660,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
nf_tables_abort_release(trans);
}
- if (action == NFNL_ABORT_AUTOLOAD)
- nf_tables_module_autoload(net);
- 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 +10673,17 @@ 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));
+
+ /* module autoload needs to happen after GC sequence update because it
+ * temporarily releases and grabs mutex again.
+ */
+ if (action == NFNL_ABORT_AUTOLOAD)
+ nf_tables_module_autoload(net);
+ else
+ nf_tables_module_autoload_cleanup(net);
+
mutex_unlock(&nft_net->commit_mutex);
return ret;
@@ -11473,9 +11489,10 @@ 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);
@@ -11567,6 +11584,7 @@ static void __exit nf_tables_module_exit(void)
unregister_netdevice_notifier(&nf_tables_flowtable_notifier);
nft_chain_filter_fini();
nft_chain_route_fini();
+ nf_tables_trans_destroy_flush_work();
unregister_pernet_subsys(&nf_tables_net_ops);
cancel_work_sync(&trans_gc_work);
cancel_work_sync(&trans_destroy_work);
