linux-stable.git/net/netfilter, branch v4.20.7

netfilter: ipset: Allow matching on destination MAC address for mac and ipmac sets

2019-01-26T08:20:39+00:00

[ Upstream commit 8cc4ccf58379935f3ad456cc34e61c4e4c921d0e ]

There doesn't seem to be any reason to restrict MAC address
matching to source MAC addresses in set types bitmap:ipmac,
hash:ipmac and hash:mac. With this patch, and this setup:

  ip netns add A
  ip link add veth1 type veth peer name veth2 netns A
  ip addr add 192.0.2.1/24 dev veth1
  ip -net A addr add 192.0.2.2/24 dev veth2
  ip link set veth1 up
  ip -net A link set veth2 up

  ip netns exec A ipset create test hash:mac
  dst=$(ip netns exec A cat /sys/class/net/veth2/address)
  ip netns exec A ipset add test ${dst}
  ip netns exec A iptables -P INPUT DROP
  ip netns exec A iptables -I INPUT -m set --match-set test dst -j ACCEPT

ipset will match packets based on destination MAC address:

  # ping -c1 192.0.2.2 >/dev/null
  # echo $?
  0

Reported-by: Yi Chen 
Signed-off-by: Stefano Brivio 
Signed-off-by: Jozsef Kadlecsik 
Signed-off-by: Sasha Levin

netfilter: nf_conncount: fix argument order to find_next_bit

2019-01-22T20:09:47+00:00

commit a007232066f6839d6f256bab21e825d968f1a163 upstream.

Size and 'next bit' were swapped, this bug could cause worker to
reschedule itself even if system was idle.

Fixes: 5c789e131cbb9 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reviewed-by: Shawn Bohrer 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conncount: speculative garbage collection on empty lists

2019-01-22T20:09:47+00:00

commit c80f10bc973af2ace6b1414724eeff61eaa71837 upstream.

Instead of removing a empty list node that might be reintroduced soon
thereafter, tentatively place the empty list node on the list passed to
tree_nodes_free(), then re-check if the list is empty again before erasing
it from the tree.

[ Florian: rebase on top of pending nf_conncount fixes ]

Fixes: 5c789e131cbb9 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reviewed-by: Shawn Bohrer 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conncount: move all list iterations under spinlock

2019-01-22T20:09:47+00:00

commit 2f971a8f425545da52ca0e6bee81f5b1ea0ccc5f upstream.

Two CPUs may race to remove a connection from the list, the existing
conn->dead will result in a use-after-free. Use the per-list spinlock to
protect list iterations.

As all accesses to the list now happen while holding the per-list lock,
we no longer need to delay free operations with rcu.

Joint work with Florian.

Fixes: 5c789e131cbb9 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reviewed-by: Shawn Bohrer 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conncount: merge lookup and add functions

2019-01-22T20:09:46+00:00

commit df4a902509766897f7371fdfa4c3bf8bc321b55d upstream.

'lookup' is always followed by 'add'.
Merge both and make the list-walk part of nf_conncount_add().

This also avoids one unneeded unlock/re-lock pair.

Extra care needs to be taken in count_tree, as we only hold rcu
read lock, i.e. we can only insert to an existing tree node after
acquiring its lock and making sure it has a nonzero count.

As a zero count should be rare, just fall back to insert_tree()
(which acquires tree lock).

This issue and its solution were pointed out by Shawn Bohrer
during patch review.

Reviewed-by: Shawn Bohrer 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conncount: restart search when nodes have been erased

2019-01-22T20:09:46+00:00

commit e8cfb372b38a1b8979aa7f7631fb5e7b11c3793c upstream.

Shawn Bohrer reported a following crash:
 |RIP: 0010:rb_erase+0xae/0x360
 [..]
 Call Trace:
  nf_conncount_destroy+0x59/0xc0 [nf_conncount]
  cleanup_match+0x45/0x70 [ip_tables]
  ...

Shawn tracked this down to bogus 'parent' pointer:
Problem is that when we insert a new node, then there is a chance that
the 'parent' that we found was also passed to tree_nodes_free() (because
that node was empty) for erase+free.

Instead of trying to be clever and detect when this happens, restart
the search if we have evicted one or more nodes.  To prevent frequent
restarts, do not perform gc on the second round.

Also, unconditionally schedule the gc worker.
The condition

  gc_count > ARRAY_SIZE(gc_nodes))

cannot be true unless tree grows very large, as the height of the tree
will be low even with hundreds of nodes present.

Fixes: 5c789e131cbb9 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reported-by: Shawn Bohrer 
Reviewed-by: Shawn Bohrer 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conncount: split gc in two phases

2019-01-22T20:09:46+00:00

commit f7fcc98dfc2d136722007fec0debbed761679b94 upstream.

The lockless workqueue garbage collector can race with packet path
garbage collector to delete list nodes, as it calls tree_nodes_free()
with the addresses of nodes that might have been free'd already from
another cpu.

To fix this, split gc into two phases.

One phase to perform gc on the connections: From a locking perspective,
this is the same as count_tree(): we hold rcu lock, but we do not
change the tree, we only change the nodes' contents.

The second phase acquires the tree lock and reaps empty nodes.
This avoids a race condition of the garbage collection vs.  packet path:
If a node has been free'd already, the second phase won't find it anymore.

This second phase is, from locking perspective, same as insert_tree().

The former only modifies nodes (list content, count), latter modifies
the tree itself (rb_erase or rb_insert).

Fixes: 5c789e131cbb9 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Reviewed-by: Shawn Bohrer 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conncount: don't skip eviction when age is negative

2019-01-22T20:09:46+00:00

commit 4cd273bb91b3001f623f516ec726c49754571b1a upstream.

age is signed integer, so result can be negative when the timestamps
have a large delta.  In this case we want to discard the entry.

Instead of using age >= 2 || age < 0, just make it unsigned.

Fixes: b36e4523d4d56 ("netfilter: nf_conncount: fix garbage collection confirm race")
Reviewed-by: Shawn Bohrer 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conncount: replace CONNCOUNT_LOCK_SLOTS with CONNCOUNT_SLOTS

2019-01-22T20:09:46+00:00

commit c78e7818f16f687389174c4569243abbec8dc68f upstream.

Most of the time these were the same value anyway, but when
CONFIG_LOCKDEP was enabled we would use a smaller number of locks to
reduce overhead.  Unfortunately having two values is confusing and not
worth the complexity.

This fixes a bug where tree_gc_worker() would only GC up to
CONNCOUNT_LOCK_SLOTS trees which meant when CONFIG_LOCKDEP was enabled
not all trees would be GCed by tree_gc_worker().

Fixes: 5c789e131cbb9 ("netfilter: nf_conncount: Add list lock and gc worker, and RCU for init tree search")
Signed-off-by: Florian Westphal 
Signed-off-by: Shawn Bohrer 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conncount: use rb_link_node_rcu() instead of rb_link_node()

2018-12-13T00:14:58+00:00

rbnode in insert_tree() is rcu protected pointer.
So, in order to handle this pointer, _rcu function should be used.
rb_link_node_rcu() is a rcu version of rb_link_node().

Fixes: 34848d5c896e ("netfilter: nf_conncount: Split insert and traversal")
Signed-off-by: Taehee Yoo 
Signed-off-by: Pablo Neira Ayuso