With CONFIG_PROVE_LOCKING, when creating a set of type bitmap:ip, adding
it to a set of type list:set and populating it from iptables SET target
triggers a kernel warning:
| WARNING: possible recursive locking detected
| 6.12.0-rc7-01692-g5e9a28f41134-dirty #594 Not tainted
| --------------------------------------------
| ping/4018 is trying to acquire lock:
| ffff8881094a6848 (&set->lock){+.-.}-{2:2}, at: ip_set_add+0x28c/0x360 [ip_set]
|
| but task is already holding lock:
| ffff88811034c048 (&set->lock){+.-.}-{2:2}, at: ip_set_add+0x28c/0x360 [ip_set]
This is a false alarm: ipset does not allow nested list:set type, so the
loop in list_set_kadd() can never encounter the outer set itself. No
other set type supports embedded sets, so this is the only case to
consider.
To avoid the false report, create a distinct lock class for list:set
type ipset locks.
Signed-off-by: Phil Sutter <phil@xxxxxx>
---
net/netfilter/ipset/ip_set_list_set.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/netfilter/ipset/ip_set_list_set.c b/net/netfilter/ipset/ip_set_list_set.c
index bfae7066936b..db794fe1300e 100644
--- a/net/netfilter/ipset/ip_set_list_set.c
+++ b/net/netfilter/ipset/ip_set_list_set.c
@@ -611,6 +611,8 @@ init_list_set(struct net *net, struct ip_set *set, u32 size)
return true;
}
+static struct lock_class_key list_set_lockdep_key;
+
static int
list_set_create(struct net *net, struct ip_set *set, struct nlattr *tb[],
u32 flags)
@@ -627,6 +629,7 @@ list_set_create(struct net *net, struct ip_set *set, struct nlattr *tb[],
if (size < IP_SET_LIST_MIN_SIZE)
size = IP_SET_LIST_MIN_SIZE;
+ lockdep_set_class(&set->lock, &list_set_lockdep_key);
set->variant = &set_variant;
set->dsize = ip_set_elem_len(set, tb, sizeof(struct set_elem),
__alignof__(struct set_elem));
--
2.47.0
