From 8837ba3e58ea1e3d09ae36db80b1e80853aada95 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 13 Nov 2023 21:13:31 +0100 Subject: [PATCH] netfilter: nf_tables: split async and sync catchall in two functions list_for_each_entry_safe() does not work for the async case which runs under RCU, therefore, split GC logic for catchall in two functions instead, one for each of the sync and async GC variants. The catchall sync GC variant never sees a _DEAD bit set on ever, thus, this handling is removed in such case, moreover, allocate GC sync batch via GFP_KERNEL. Fixes: 93995bf4af2c ("netfilter: nf_tables: remove catchall element in GC sync path") Reported-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 55 +++++++++++++++++++---------------- 1 file changed, 30 insertions(+), 25 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index debea1c67701..c0a42989b982 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -9680,16 +9680,14 @@ void nft_trans_gc_queue_sync_done(struct nft_trans_gc *trans) call_rcu(&trans->rcu, nft_trans_gc_trans_free); } -static struct nft_trans_gc *nft_trans_gc_catchall(struct nft_trans_gc *gc, - unsigned int gc_seq, - bool sync) +struct nft_trans_gc *nft_trans_gc_catchall_async(struct nft_trans_gc *gc, + unsigned int gc_seq) { - struct nft_set_elem_catchall *catchall, *next; + struct nft_set_elem_catchall *catchall; const struct nft_set *set = gc->set; - struct nft_elem_priv *elem_priv; struct nft_set_ext *ext; - list_for_each_entry_safe(catchall, next, &set->catchall_list, list) { + list_for_each_entry_rcu(catchall, &set->catchall_list, list) { ext = nft_set_elem_ext(set, catchall->elem); if (!nft_set_elem_expired(ext)) @@ -9699,35 +9697,42 @@ static struct nft_trans_gc *nft_trans_gc_catchall(struct nft_trans_gc *gc, nft_set_elem_dead(ext); dead_elem: - if (sync) - gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC); - else - gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC); - + gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC); if (!gc) return NULL; - elem_priv = catchall->elem; - if (sync) { - nft_setelem_data_deactivate(gc->net, gc->set, elem_priv); - nft_setelem_catchall_destroy(catchall); - } - - nft_trans_gc_elem_add(gc, elem_priv); + nft_trans_gc_elem_add(gc, catchall->elem); } return gc; } -struct nft_trans_gc *nft_trans_gc_catchall_async(struct nft_trans_gc *gc, - unsigned int gc_seq) -{ - return nft_trans_gc_catchall(gc, gc_seq, false); -} - struct nft_trans_gc *nft_trans_gc_catchall_sync(struct nft_trans_gc *gc) { - return nft_trans_gc_catchall(gc, 0, true); + struct nft_set_elem_catchall *catchall, *next; + const struct nft_set *set = gc->set; + struct nft_elem_priv *elem_priv; + struct nft_set_ext *ext; + + WARN_ON_ONCE(!lockdep_commit_lock_is_held(gc->net)); + + list_for_each_entry_safe(catchall, next, &set->catchall_list, list) { + ext = nft_set_elem_ext(set, catchall->elem); + + if (!nft_set_elem_expired(ext)) + continue; + + gc = nft_trans_gc_queue_sync(gc, GFP_KERNEL); + if (!gc) + return NULL; + + elem_priv = catchall->elem; + nft_setelem_data_deactivate(gc->net, gc->set, elem_priv); + nft_setelem_catchall_destroy(catchall); + nft_trans_gc_elem_add(gc, elem_priv); + } + + return gc; } static void nf_tables_module_autoload_cleanup(struct net *net)