From: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxx>
When destroying all sets, we are either in pernet exit phase or
are executing a "destroy all sets command" from userspace. The latter
was taken into account in ip_set_dereference() (nfnetlink mutex is held),
but the former was not. The patch adds the required check to
rcu_dereference_protected() in ip_set_dereference().
Fixes: 4e7aaa6b82d6 ("netfilter: ipset: Fix race between namespace cleanup and gc in the list:set type")
Reported-by: syzbot+b62c37cdd58103293a5a@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot+cfbe1da5fdfc39efc293@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-lkp/202406141556.e0b6f17e-lkp@xxxxxxxxx
Signed-off-by: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/ipset/ip_set_core.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index c7ae4d9bf3d2..61431690cbd5 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -53,12 +53,13 @@ MODULE_DESCRIPTION("core IP set support");
MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_IPSET);
/* When the nfnl mutex or ip_set_ref_lock is held: */
-#define ip_set_dereference(p) \
- rcu_dereference_protected(p, \
+#define ip_set_dereference(inst) \
+ rcu_dereference_protected((inst)->ip_set_list, \
lockdep_nfnl_is_held(NFNL_SUBSYS_IPSET) || \
- lockdep_is_held(&ip_set_ref_lock))
+ lockdep_is_held(&ip_set_ref_lock) || \
+ (inst)->is_deleted)
#define ip_set(inst, id) \
- ip_set_dereference((inst)->ip_set_list)[id]
+ ip_set_dereference(inst)[id]
#define ip_set_ref_netlink(inst,id) \
rcu_dereference_raw((inst)->ip_set_list)[id]
#define ip_set_dereference_nfnl(p) \
@@ -1133,7 +1134,7 @@ static int ip_set_create(struct sk_buff *skb, const struct nfnl_info *info,
if (!list)
goto cleanup;
/* nfnl mutex is held, both lists are valid */
- tmp = ip_set_dereference(inst->ip_set_list);
+ tmp = ip_set_dereference(inst);
memcpy(list, tmp, sizeof(struct ip_set *) * inst->ip_set_max);
rcu_assign_pointer(inst->ip_set_list, list);
/* Make sure all current packets have passed through */
--
2.30.2
