linux-stable.git/net/bridge, branch v5.14.2

net: bridge: fix memleak in br_add_if()

2021-08-10T20:25:14+00:00

I got a memleak report:

BUG: memory leak
unreferenced object 0x607ee521a658 (size 240):
comm "syz-executor.0", pid 955, jiffies 4294780569 (age 16.449s)
hex dump (first 32 bytes, cpu 1):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000d830ea5a>] br_multicast_add_port+0x1c2/0x300 net/bridge/br_multicast.c:1693
[<00000000274d9a71>] new_nbp net/bridge/br_if.c:435 [inline]
[<00000000274d9a71>] br_add_if+0x670/0x1740 net/bridge/br_if.c:611
[<0000000012ce888e>] do_set_master net/core/rtnetlink.c:2513 [inline]
[<0000000012ce888e>] do_set_master+0x1aa/0x210 net/core/rtnetlink.c:2487
[<0000000099d1cafc>] __rtnl_newlink+0x1095/0x13e0 net/core/rtnetlink.c:3457
[<00000000a01facc0>] rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3488
[<00000000acc9186c>] rtnetlink_rcv_msg+0x369/0xa10 net/core/rtnetlink.c:5550
[<00000000d4aabb9c>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504
[<00000000bc2e12a3>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
[<00000000bc2e12a3>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340
[<00000000e4dc2d0e>] netlink_sendmsg+0x789/0xc70 net/netlink/af_netlink.c:1929
[<000000000d22c8b3>] sock_sendmsg_nosec net/socket.c:654 [inline]
[<000000000d22c8b3>] sock_sendmsg+0x139/0x170 net/socket.c:674
[<00000000e281417a>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350
[<00000000237aa2ab>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404
[<000000004f2dc381>] __sys_sendmsg+0xd3/0x190 net/socket.c:2433
[<0000000005feca6c>] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:47
[<000000007304477d>] entry_SYSCALL_64_after_hwframe+0x44/0xae

On error path of br_add_if(), p->mcast_stats allocated in
new_nbp() need be freed, or it will be leaked.

Fixes: 1080ab95e3c7 ("net: bridge: add support for IGMP/MLD stats and export them via netlink")
Reported-by: Hulk Robot 
Signed-off-by: Yang Yingliang 
Acked-by: Nikolay Aleksandrov 
Link: https://lore.kernel.org/r/20210809132023.978546-1-yangyingliang@huawei.com
Signed-off-by: Jakub Kicinski

net: bridge: fix flags interpretation for extern learn fdb entries

2021-08-10T18:29:39+00:00

Ignore fdb flags when adding port extern learn entries and always set
BR_FDB_LOCAL flag when adding bridge extern learn entries. This is
closest to the behaviour we had before and avoids breaking any use cases
which were allowed.

This patch fixes iproute2 calls which assume NUD_PERMANENT and were
allowed before, example:
$ bridge fdb add 00:11:22:33:44:55 dev swp1 extern_learn

Extern learn entries are allowed to roam, but do not expire, so static
or dynamic flags make no sense for them.

Also add a comment for future reference.

Fixes: eb100e0e24a2 ("net: bridge: allow to add externally learned entries from user-space")
Fixes: 0541a6293298 ("net: bridge: validate the NUD_PERMANENT bit when adding an extern_learn FDB entry")
Reviewed-by: Ido Schimmel 
Tested-by: Ido Schimmel 
Signed-off-by: Nikolay Aleksandrov 
Reviewed-by: Vladimir Oltean 
Link: https://lore.kernel.org/r/20210810110010.43859-1-razor@blackwall.org
Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

2021-08-06T15:44:50+00:00

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Restrict range element expansion in ipset to avoid soft lockup,
   from Jozsef Kadlecsik.

2) Memleak in error path for nf_conntrack_bridge for IPv4 packets,
   from Yajun Deng.

3) Simplify conntrack garbage collection strategy to avoid frequent
   wake-ups, from Florian Westphal.

4) Fix NFNLA_HOOK_FUNCTION_NAME string, do not include module name.

5) Missing chain family netlink attribute in chain description
   in nfnetlink_hook.

6) Incorrect sequence number on nfnetlink_hook dumps.

7) Use netlink request family in reply message for consistency.

8) Remove offload_pickup sysctl, use conntrack for established state
   instead, from Florian Westphal.

9) Translate NFPROTO_INET/ingress to NFPROTO_NETDEV/ingress, since
   NFPROTO_INET is not exposed through nfnetlink_hook.

* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf:
  netfilter: nfnetlink_hook: translate inet ingress to netdev
  netfilter: conntrack: remove offload_pickup sysctl again
  netfilter: nfnetlink_hook: Use same family as request message
  netfilter: nfnetlink_hook: use the sequence number of the request message
  netfilter: nfnetlink_hook: missing chain family
  netfilter: nfnetlink_hook: strip off module name from hookfn
  netfilter: conntrack: collect all entries in one cycle
  netfilter: nf_conntrack_bridge: Fix memory leak when error
  netfilter: ipset: Limit the maximal range of consecutive elements to add/delete
====================

Link: https://lore.kernel.org/r/20210806151149.6356-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski

netfilter: nf_conntrack_bridge: Fix memory leak when error

2021-08-04T08:41:29+00:00

It should be added kfree_skb_list() when err is not equal to zero
in nf_br_ip_fragment().

v2: keep this aligned with IPv6.
v3: modify iter.frag_list to iter.frag.

Fixes: 3c171f496ef5 ("netfilter: bridge: add connection tracking system")
Signed-off-by: Yajun Deng 
Signed-off-by: Pablo Neira Ayuso

net: bridge: validate the NUD_PERMANENT bit when adding an extern_learn FDB entry

2021-08-02T22:00:48+00:00

Currently it is possible to add broken extern_learn FDB entries to the
bridge in two ways:

1. Entries pointing towards the bridge device that are not local/permanent:

ip link add br0 type bridge
bridge fdb add 00:01:02:03:04:05 dev br0 self extern_learn static

2. Entries pointing towards the bridge device or towards a port that
are marked as local/permanent, however the bridge does not process the
'permanent' bit in any way, therefore they are recorded as though they
aren't permanent:

ip link add br0 type bridge
bridge fdb add 00:01:02:03:04:05 dev br0 self extern_learn permanent

Since commit 52e4bec15546 ("net: bridge: switchdev: treat local FDBs the
same as entries towards the bridge"), these incorrect FDB entries can
even trigger NULL pointer dereferences inside the kernel.

This is because that commit made the assumption that all FDB entries
that are not local/permanent have a valid destination port. For context,
local / permanent FDB entries either have fdb->dst == NULL, and these
point towards the bridge device and are therefore local and not to be
used for forwarding, or have fdb->dst == a net_bridge_port structure
(but are to be treated in the same way, i.e. not for forwarding).

That assumption _is_ correct as long as things are working correctly in
the bridge driver, i.e. we cannot logically have fdb->dst == NULL under
any circumstance for FDB entries that are not local. However, the
extern_learn code path where FDB entries are managed by a user space
controller show that it is possible for the bridge kernel driver to
misinterpret the NUD flags of an entry transmitted by user space, and
end up having fdb->dst == NULL while not being a local entry. This is
invalid and should be rejected.

Before, the two commands listed above both crashed the kernel in this
check from br_switchdev_fdb_notify:

	struct net_device *dev = info.is_local ? br->dev : dst->dev;

info.is_local == false, dst == NULL.

After this patch, the invalid entry added by the first command is
rejected:

ip link add br0 type bridge && bridge fdb add 00:01:02:03:04:05 dev br0 self extern_learn static; ip link del br0
Error: bridge: FDB entry towards bridge must be permanent.

and the valid entry added by the second command is properly treated as a
local address and does not crash br_switchdev_fdb_notify anymore:

ip link add br0 type bridge && bridge fdb add 00:01:02:03:04:05 dev br0 self extern_learn permanent; ip link del br0

Fixes: eb100e0e24a2 ("net: bridge: allow to add externally learned entries from user-space")
Reported-by: syzbot+9ba1174359adba5a5b7c@syzkaller.appspotmail.com
Signed-off-by: Vladimir Oltean 
Acked-by: Nikolay Aleksandrov 
Link: https://lore.kernel.org/r/20210801231730.7493-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski

net: bridge: do not replay fdb entries pointing towards the bridge twice

2021-07-20T11:08:45+00:00

This simple script:

ip link add br0 type bridge
ip link set swp2 master br0
ip link set br0 address 00:01:02:03:04:05
ip link del br0

produces this result on a DSA switch:

[  421.306399] br0: port 1(swp2) entered blocking state
[  421.311445] br0: port 1(swp2) entered disabled state
[  421.472553] device swp2 entered promiscuous mode
[  421.488986] device swp2 left promiscuous mode
[  421.493508] br0: port 1(swp2) entered disabled state
[  421.886107] sja1105 spi0.1: port 1 failed to delete 00:01:02:03:04:05 vid 1 from fdb: -ENOENT
[  421.894374] sja1105 spi0.1: port 1 failed to delete 00:01:02:03:04:05 vid 0 from fdb: -ENOENT
[  421.943982] br0: port 1(swp2) entered blocking state
[  421.949030] br0: port 1(swp2) entered disabled state
[  422.112504] device swp2 entered promiscuous mode

A very simplified view of what happens is:

(1) the bridge port is created, and the bridge device inherits its MAC
    address

(2) when joining, the bridge port (DSA) requests a replay of the
    addition of all FDB entries towards this bridge port and towards the
    bridge device itself. In fact, DSA calls br_fdb_replay() twice:

	br_fdb_replay(br, brport_dev);
	br_fdb_replay(br, br);

    DSA uses reference counting for the FDB entries. So the MAC address
    of the bridge is simply kept with refcount 2. When the bridge port
    leaves under normal circumstances, everything cancels out since the
    replay of the FDB entry deletion is also done twice per VLAN.

(3) when the bridge MAC address changes, switchdev is notified of the
    deletion of the old address and of the insertion of the new one.
    But the old address does not really go away, since it had refcount
    2, and the new address is added "only" with refcount 1.

(4) when the bridge port leaves now, it will replay a deletion of the
    FDB entries pointing towards the bridge twice. Then DSA will
    complain that it can't delete something that no longer exists.

It is clear that the problem is that the FDB entries towards the bridge
are replayed too many times, so let's fix that problem.

Fixes: 63c51453c82c ("net: dsa: replay the local bridge FDB entries pointing to the bridge dev too")
Signed-off-by: Vladimir Oltean 
Link: https://lore.kernel.org/r/20210719093916.4099032-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski

net: bridge: multicast: fix MRD advertisement router port marking race

2021-07-11T19:11:06+00:00

When an MRD advertisement is received on a bridge port with multicast
snooping enabled, we mark it as a router port automatically, that
includes adding that port to the router port list. The multicast lock
protects that list, but it is not acquired in the MRD advertisement case
leading to a race condition, we need to take it to fix the race.

Cc: stable@vger.kernel.org
Cc: linus.luessing@c0d3.blue
Fixes: 4b3087c7e37f ("bridge: Snoop Multicast Router Advertisements")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bridge: multicast: fix PIM hello router port marking race

2021-07-11T19:11:06+00:00

When a PIM hello packet is received on a bridge port with multicast
snooping enabled, we mark it as a router port automatically, that
includes adding that port the router port list. The multicast lock
protects that list, but it is not acquired in the PIM message case
leading to a race condition, we need to take it to fix the race.

Cc: stable@vger.kernel.org
Fixes: 91b02d3d133b ("bridge: mcast: add router port on PIM hello message")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bridge: sync fdb to new unicast-filtering ports

2021-07-02T20:34:07+00:00

Since commit 2796d0c648c9 ("bridge: Automatically manage
port promiscuous mode.")
bridges with `vlan_filtering 1` and only 1 auto-port don't
set IFF_PROMISC for unicast-filtering-capable ports.

Normally on port changes `br_manage_promisc` is called to
update the promisc flags and unicast filters if necessary,
but it cannot distinguish between *new* ports and ones
losing their promisc flag, and new ports end up not
receiving the MAC address list.

Fix this by calling `br_fdb_sync_static` in `br_add_if`
after the port promisc flags are updated and the unicast
filter was supposed to have been filled.

Fixes: 2796d0c648c9 ("bridge: Automatically manage port promiscuous mode.")
Signed-off-by: Wolfgang Bumiller 
Acked-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bridge: allow br_fdb_replay to be called for the bridge device

2021-06-29T17:46:23+00:00

When a port joins a bridge which already has local FDB entries pointing
to the bridge device itself, we would like to offload those, so allow
the "dev" argument to be equal to the bridge too. The code already does
what we need in that case.

Signed-off-by: Vladimir Oltean 
Signed-off-by: David S. Miller