diff options
| author | Jozsef Kadlecsik <kadlec@netfilter.org> | 2024-01-29 12:30:23 +0100 |
|---|---|---|
| committer | Jozsef Kadlecsik <kadlec@netfilter.org> | 2024-01-29 12:30:23 +0100 |
| commit | 148fad4dcc41bd07b52ed3ccca5f40765e9cf692 (patch) | |
| tree | 8dabf3d719bfc7875f6c71254aca764821f27025 /kernel/net/netfilter/ipset/ip_set_bitmap_gen.h | |
| parent | 0378d91222c1aba5a766c3d745574ed1c59cbf8f (diff) | |
netfilter: ipset: fix race condition between swap/destroy and kernel side add/del/test v4
The patch "netfilter: ipset: fix race condition between swap/destroy
and kernel side add/del/test", commit 28628fa9 fixes a race condition.
But the synchronize_rcu() added to the swap function unnecessarily slows
it down: it can safely be moved to destroy and use call_rcu() instead.
Eric Dumazet pointed out that simply calling the destroy functions as
rcu callback does not work: sets with timeout use garbage collectors
which need cancelling at destroy which can wait. Therefore the destroy
functions are split into two: cancelling garbage collectors safely at
executing the command received by netlink and moving the remaining
part only into the rcu callback.
Link: https://lore.kernel.org/lkml/C0829B10-EAA6-4809-874E-E1E9C05A8D84@automattic.com/
Fixes: 28628fa952fe ("netfilter: ipset: fix race condition between swap/destroy and kernel side add/del/test")
Reported-by: Ale Crismani <ale.crismani@automattic.com>
Reported-by: David Wang <00107082@163.com>
Tested-by: David Wang <00107082@163.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Diffstat (limited to 'kernel/net/netfilter/ipset/ip_set_bitmap_gen.h')
| -rw-r--r-- | kernel/net/netfilter/ipset/ip_set_bitmap_gen.h | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/kernel/net/netfilter/ipset/ip_set_bitmap_gen.h b/kernel/net/netfilter/ipset/ip_set_bitmap_gen.h index 0479750..3245b6b 100644 --- a/kernel/net/netfilter/ipset/ip_set_bitmap_gen.h +++ b/kernel/net/netfilter/ipset/ip_set_bitmap_gen.h @@ -29,6 +29,7 @@ #define mtype_del IPSET_TOKEN(MTYPE, _del) #define mtype_list IPSET_TOKEN(MTYPE, _list) #define mtype_gc IPSET_TOKEN(MTYPE, _gc) +#define mtype_cancel_gc IPSET_TOKEN(MTYPE, _cancel_gc) #define mtype MTYPE #define get_ext(set, map, id) ((map)->extensions + ((set)->dsize * (id))) @@ -58,9 +59,6 @@ mtype_destroy(struct ip_set *set) { struct mtype *map = set->data; - if (SET_WITH_TIMEOUT(set)) - del_timer_sync(&map->gc); - if (set->dsize && set->extensions & IPSET_EXT_DESTROY) mtype_ext_cleanup(set); ip_set_free(map->members); @@ -290,6 +288,15 @@ mtype_gc(GC_ARG) add_timer(&map->gc); } +static void +mtype_cancel_gc(struct ip_set *set) +{ + struct mtype *map = set->data; + + if (SET_WITH_TIMEOUT(set)) + del_timer_sync(&map->gc); +} + static const struct ip_set_type_variant mtype = { .kadt = mtype_kadt, .uadt = mtype_uadt, @@ -303,6 +310,7 @@ static const struct ip_set_type_variant mtype = { .head = mtype_head, .list = mtype_list, .same_set = mtype_same_set, + .cancel_gc = mtype_cancel_gc, }; #endif /* __IP_SET_BITMAP_IP_GEN_H */ |