[PATCH 4/5] netfilter: nft_set_hash: mark set element as dead when deleting from packet path

[Lee Jones <lee@kernel.org>]

From: Pablo Neira Ayuso <pablo@netfilter.org>

[ Upstream commit c92db3030492b8ad1d0faace7a93bbcf53850d0c ]

Set on the NFT_SET_ELEM_DEAD_BIT flag on this element, instead of
performing element removal which might race with an ongoing transaction.
Enable gc when dynamic flag is set on since dynset deletion requires
garbage collection after this patch.

Fixes: d0a8d877da97 ("netfilter: nft_dynset: support for element deletion")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Lee Jones <joneslee@google.com>
---
 net/netfilter/nft_set_hash.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index 2f067e4596b02..cef5df8460009 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -249,7 +249,9 @@ static bool nft_rhash_delete(const struct nft_set *set,
 	if (he == NULL)
 		return false;
 
-	return rhashtable_remove_fast(&priv->ht, &he->node, nft_rhash_params) == 0;
+	nft_set_elem_dead(&he->ext);
+
+	return true;
 }
 
 static void nft_rhash_walk(const struct nft_ctx *ctx, struct nft_set *set,
@@ -412,7 +414,7 @@ static int nft_rhash_init(const struct nft_set *set,
 		return err;
 
 	INIT_DEFERRABLE_WORK(&priv->gc_work, nft_rhash_gc);
-	if (set->flags & NFT_SET_TIMEOUT)
+	if (set->flags & (NFT_SET_TIMEOUT | NFT_SET_EVAL))
 		nft_rhash_gc_init(set);
 
 	return 0;
-- 
2.42.0.459.ge4e396fd5e-goog