From 8a13595600f7a66c3598bd74ad1c17e2d7ce0a9f Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sat, 14 Jan 2023 23:49:46 +0100 Subject: [PATCH] netfilter: nft_set_rbtree: skip elements in transaction from garbage collection [ Upstream commit 5d235d6ce75c12a7fdee375eb211e4116f7ab01b ] Skip interference with an ongoing transaction, do not perform garbage collection on inactive elements. Reset annotated previous end interval if the expired element is marked as busy (control plane removed the element right before expiration). Fixes: 8d8540c4f5e0 ("netfilter: nft_set_rbtree: add timeout support") Reviewed-by: Stefano Brivio Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nft_set_rbtree.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c index 217225e..19ea4d3 100644 --- a/net/netfilter/nft_set_rbtree.c +++ b/net/netfilter/nft_set_rbtree.c @@ -563,23 +563,37 @@ static void nft_rbtree_gc(struct work_struct *work) struct nft_rbtree *priv; struct rb_node *node; struct nft_set *set; + struct net *net; + u8 genmask; priv = container_of(work, struct nft_rbtree, gc_work.work); set = nft_set_container_of(priv); + net = read_pnet(&set->net); + genmask = nft_genmask_cur(net); write_lock_bh(&priv->lock); write_seqcount_begin(&priv->count); for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) { rbe = rb_entry(node, struct nft_rbtree_elem, node); + if (!nft_set_elem_active(&rbe->ext, genmask)) + continue; + + /* elements are reversed in the rbtree for historical reasons, + * from highest to lowest value, that is why end element is + * always visited before the start element. + */ if (nft_rbtree_interval_end(rbe)) { rbe_end = rbe; continue; } if (!nft_set_elem_expired(&rbe->ext)) continue; - if (nft_set_elem_mark_busy(&rbe->ext)) + + if (nft_set_elem_mark_busy(&rbe->ext)) { + rbe_end = NULL; continue; + } if (rbe_prev) { rb_erase(&rbe_prev->node, &priv->root); -- 2.7.4