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.

Fixes: f830837f0eed ("netfilter: ipset: list:set set type support")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

User space may unload ip_set.ko while it is itself requesting a set type
backend module, leading to a kernel crash. The race condition may be
provoked by inserting an mdelay() right after the nfnl_unlock() call.

Fixes: a7b4f989a629 ("netfilter: ipset: IP set core support")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

When tb[IPSET_ATTR_IP_TO] is not present but tb[IPSET_ATTR_CIDR] exists,
the values of ip and ip_to are slightly swapped. Therefore, the range check
for ip should be done later, but this part is missing and it seems that the
vulnerability occurs.

So we should add missing range checks and remove unnecessary range checks.

Cc: <stable@vger.kernel.org>
Reported-by: syzbot+58c872f7790a4d2ac951@syzkaller.appspotmail.com
Fixes: 72205fc68bd1 ("netfilter: ipset: bitmap:ip set type support")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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@syzkaller.appspotmail.com
Reported-by: syzbot+cfbe1da5fdfc39efc293@syzkaller.appspotmail.com
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202406141556.e0b6f17e-lkp@intel.com
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Lion Ackermann reported that there is a race condition between namespace cleanup
in ipset and the garbage collection of the list:set type. The namespace
cleanup can destroy the list:set type of sets while the gc of the set type is
waiting to run in rcu cleanup. The latter uses data from the destroyed set which
thus leads use after free. The patch contains the following parts:

- When destroying all sets, first remove the garbage collectors, then wait
  if needed and then destroy the sets.
- Fix the badly ordered "wait then remove gc" for the destroy a single set
  case.
- Fix the missing rcu locking in the list:set type in the userspace test
  case.
- Use proper RCU list handlings in the list:set type.

The patch depends on c1193d9bbbd3 (netfilter: ipset: Add list flush to cancel_gc).

Fixes: 97f7cf1cd80e (netfilter: ipset: fix performance regression in swap operation)
Reported-by: Lion Ackermann <nnamrec@gmail.com>
Tested-by: Lion Ackermann <nnamrec@gmail.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Flushing list in cancel_gc drops references to other lists right away,
without waiting for RCU to destroy list. Fixes race when referenced
ipsets can't be destroyed while referring list is scheduled for destroy.

Fixes: 97f7cf1cd80e ("netfilter: ipset: fix performance regression in swap operation")
Signed-off-by: Alexander Maltsev <keltar.gw@gmail.com>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

The patch fdb8e12cc2cc ("netfilter: ipset: fix performance regression
in swap operation") missed to add the calls to gc cancellations
at the error path of create operations and at module unload. Also,
because the half of the destroy operations now executed by a
function registered by call_rcu(), neither NFNL_SUBSYS_IPSET mutex
or rcu read lock is held and therefore the checking of them results
false warnings.

Fixes: 97f7cf1cd80e ("netfilter: ipset: fix performance regression in swap operation")
Reported-by: syzbot+52bbc0ad036f6f0d4a25@syzkaller.appspotmail.com
Reported-by: Brad Spengler <spender@grsecurity.net>
Reported-by: Стас Ничипорович <stasn77@gmail.com>
Tested-by: Brad Spengler <spender@grsecurity.net>
Tested-by: Стас Ничипорович <stasn77@gmail.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This is a preparation patch for replacing physindev with physinif on
nf_bridge_info structure. We will use dev_get_by_index_rcu to resolve
device, when needed, and it requires net to be available.

Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

by moving cond_resched_rcu() to rcupdate_wait.h, we can kill another big
sched.h dependency.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>