diff options
| author | Jozsef Kadlecsik <kadlec@netfilter.org> | 2023-09-18 23:10:51 +0200 |
|---|---|---|
| committer | Jozsef Kadlecsik <kadlec@netfilter.org> | 2023-09-18 23:10:51 +0200 |
| commit | c63afc87e554f3742b7c2cd9c401cefb632bb38a (patch) | |
| tree | ba7f5022662a2a011c186d36e9c9562463b6bfbe | |
| parent | 39dfa583c317d6e62290b1276a5b8b58afc7f951 (diff) | |
netfilter: ipset: Fix race between IPSET_CMD_CREATE and IPSET_CMD_SWAP
Kyle Zeng reported that there is a race between IPSET_CMD_ADD and IPSET_CMD_SWAP
in netfilter/ip_set, which can lead to the invocation of `__ip_set_put` on a wrong
`set`, triggering the `BUG_ON(set->ref == 0);` check in it.
The race is caused by using the wrong reference counter, i.e. the ref counter instead
of ref_netlink.
Reported-by: Kyle Zeng <zengyhkyle@gmail.com>
Tested-by: Kyle Zeng <zengyhkyle@gmail.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
| -rw-r--r-- | kernel/net/netfilter/ipset/ip_set_core.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/net/netfilter/ipset/ip_set_core.c b/kernel/net/netfilter/ipset/ip_set_core.c index 1a647c5..484e798 100644 --- a/kernel/net/netfilter/ipset/ip_set_core.c +++ b/kernel/net/netfilter/ipset/ip_set_core.c @@ -684,6 +684,14 @@ __ip_set_put(struct ip_set *set) * a separate reference counter */ static void +__ip_set_get_netlink(struct ip_set *set) +{ + write_lock_bh(&ip_set_ref_lock); + set->ref_netlink++; + write_unlock_bh(&ip_set_ref_lock); +} + +static void __ip_set_put_netlink(struct ip_set *set) { write_lock_bh(&ip_set_ref_lock); @@ -1749,11 +1757,11 @@ CALL_AD(struct net *net, struct sock *ctnl, struct sk_buff *skb, do { if (retried) { - __ip_set_get(set); + __ip_set_get_netlink(set); nfnl_unlock(NFNL_SUBSYS_IPSET); cond_resched(); nfnl_lock(NFNL_SUBSYS_IPSET); - __ip_set_put(set); + __ip_set_put_netlink(set); } ip_set_lock(set); |