netfilter: ipset: Fix race between IPSET_CMD_CREATE and IPSET_CMD_SWAP
[ Upstream commit 7433b6d2afd512d04398c73aa984d1e285be125b ] 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. Fixes: 24e227896bbf ("netfilter: ipset: Add schedule point in call_ad().") Reported-by: Kyle Zeng <zengyhkyle@gmail.com> Closes: https://lore.kernel.org/netfilter-devel/ZPZqetxOmH+w%2Fmyc@westworld/#r Tested-by: Kyle Zeng <zengyhkyle@gmail.com> Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
parent
812da2a08d
commit
02a233986c
@ -530,6 +530,14 @@ __ip_set_put(struct ip_set *set)
|
||||
/* set->ref can be swapped out by ip_set_swap, netlink events (like dump) need
|
||||
* 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 inline void
|
||||
__ip_set_put_netlink(struct ip_set *set)
|
||||
{
|
||||
@ -1529,11 +1537,11 @@ call_ad(struct sock *ctnl, struct sk_buff *skb, struct ip_set *set,
|
||||
|
||||
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);
|
||||
|
Loading…
Reference in New Issue
Block a user