[PATCH 6.1 283/303] netfilter: ipset: let destroy callbacks adjust ext mem size

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Florian Westphal <[email protected]>

[ Upstream commit 490937b88cb592cc0c5367758edd700fd5abd15c ]

For bitmap this change makes no difference, because destructors are
called synchronously.

List type however calls them via call_rcu() so accounting decrement can
happen after list_set_flush() set ext_size to 0.

'set->elements = 0' can be removed for the same reason in the list type
case, it calls 'set->elements--' for each element.

Fixes: 9e41f26a505c ("netfilter: ipset: Count non-static extension memory for userspace")
Suggested-by: Jozsef Kadlecsik <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
Acked-by: Jozsef Kadlecsik <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
 net/netfilter/ipset/ip_set_bitmap_gen.h | 2 +-
 net/netfilter/ipset/ip_set_list_set.c   | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/ipset/ip_set_bitmap_gen.h b/net/netfilter/ipset/ip_set_bitmap_gen.h
index 40f0383883f9d..605d54d2bd7e6 100644
--- a/net/netfilter/ipset/ip_set_bitmap_gen.h
+++ b/net/netfilter/ipset/ip_set_bitmap_gen.h
@@ -75,7 +75,7 @@ mtype_flush(struct ip_set *set)
 		mtype_ext_cleanup(set);
 	bitmap_zero(map->members, map->elements);
 	set->elements = 0;
-	atomic64_set(&set->ext_size, 0);
+	DEBUG_NET_WARN_ON_ONCE(atomic64_read(&set->ext_size) > 0);
 }
 
 /* Calculate the actual memory size of the set data */
diff --git a/net/netfilter/ipset/ip_set_list_set.c b/net/netfilter/ipset/ip_set_list_set.c
index 848fbafd2593d..139df33149119 100644
--- a/net/netfilter/ipset/ip_set_list_set.c
+++ b/net/netfilter/ipset/ip_set_list_set.c
@@ -423,8 +423,7 @@ list_set_flush(struct ip_set *set)
 
 	list_for_each_entry_safe(e, n, &map->members, list)
 		list_set_del(set, e);
-	set->elements = 0;
-	atomic64_set(&set->ext_size, 0);
+	DEBUG_NET_WARN_ON_ONCE(set->elements > 0);
 }
 
 static void
-- 
2.53.0