linux-stable.git/net/bridge, branch v5.13.2

net: bridge: fix vlan tunnel dst refcnt when egressing

2021-06-10T21:06:43+00:00

The egress tunnel code uses dst_clone() and directly sets the result
which is wrong because the entry might have 0 refcnt or be already deleted,
causing number of problems. It also triggers the WARN_ON() in dst_hold()[1]
when a refcnt couldn't be taken. Fix it by using dst_hold_safe() and
checking if a reference was actually taken before setting the dst.

[1] dmesg WARN_ON log and following refcnt errors
 WARNING: CPU: 5 PID: 38 at include/net/dst.h:230 br_handle_egress_vlan_tunnel+0x10b/0x134 [bridge]
 Modules linked in: 8021q garp mrp bridge stp llc bonding ipv6 virtio_net
 CPU: 5 PID: 38 Comm: ksoftirqd/5 Kdump: loaded Tainted: G        W         5.13.0-rc3+ #360
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
 RIP: 0010:br_handle_egress_vlan_tunnel+0x10b/0x134 [bridge]
 Code: e8 85 bc 01 e1 45 84 f6 74 90 45 31 f6 85 db 48 c7 c7 a0 02 19 a0 41 0f 94 c6 31 c9 31 d2 44 89 f6 e8 64 bc 01 e1 85 db 75 02 <0f> 0b 31 c9 31 d2 44 89 f6 48 c7 c7 70 02 19 a0 e8 4b bc 01 e1 49
 RSP: 0018:ffff8881003d39e8 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffffa01902a0
 RBP: ffff8881040c6700 R08: 0000000000000000 R09: 0000000000000001
 R10: 2ce93d0054fe0d00 R11: 54fe0d00000e0000 R12: ffff888109515000
 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000401
 FS:  0000000000000000(0000) GS:ffff88822bf40000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f42ba70f030 CR3: 0000000109926000 CR4: 00000000000006e0
 Call Trace:
  br_handle_vlan+0xbc/0xca [bridge]
  __br_forward+0x23/0x164 [bridge]
  deliver_clone+0x41/0x48 [bridge]
  br_handle_frame_finish+0x36f/0x3aa [bridge]
  ? skb_dst+0x2e/0x38 [bridge]
  ? br_handle_ingress_vlan_tunnel+0x3e/0x1c8 [bridge]
  ? br_handle_frame_finish+0x3aa/0x3aa [bridge]
  br_handle_frame+0x2c3/0x377 [bridge]
  ? __skb_pull+0x33/0x51
  ? vlan_do_receive+0x4f/0x36a
  ? br_handle_frame_finish+0x3aa/0x3aa [bridge]
  __netif_receive_skb_core+0x539/0x7c6
  ? __list_del_entry_valid+0x16e/0x1c2
  __netif_receive_skb_list_core+0x6d/0xd6
  netif_receive_skb_list_internal+0x1d9/0x1fa
  gro_normal_list+0x22/0x3e
  dev_gro_receive+0x55b/0x600
  ? detach_buf_split+0x58/0x140
  napi_gro_receive+0x94/0x12e
  virtnet_poll+0x15d/0x315 [virtio_net]
  __napi_poll+0x2c/0x1c9
  net_rx_action+0xe6/0x1fb
  __do_softirq+0x115/0x2d8
  run_ksoftirqd+0x18/0x20
  smpboot_thread_fn+0x183/0x19c
  ? smpboot_unregister_percpu_thread+0x66/0x66
  kthread+0x10a/0x10f
  ? kthread_mod_delayed_work+0xb6/0xb6
  ret_from_fork+0x22/0x30
 ---[ end trace 49f61b07f775fd2b ]---
 dst_release: dst:00000000c02d677a refcnt:-1
 dst_release underflow

Cc: stable@vger.kernel.org
Fixes: 11538d039ac6 ("bridge: vlan dst_metadata hooks in ingress and egress paths")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bridge: fix vlan tunnel dst null pointer dereference

2021-06-10T21:06:43+00:00

This patch fixes a tunnel_dst null pointer dereference due to lockless
access in the tunnel egress path. When deleting a vlan tunnel the
tunnel_dst pointer is set to NULL without waiting a grace period (i.e.
while it's still usable) and packets egressing are dereferencing it
without checking. Use READ/WRITE_ONCE to annotate the lockless use of
tunnel_id, use RCU for accessing tunnel_dst and make sure it is read
only once and checked in the egress path. The dst is already properly RCU
protected so we don't need to do anything fancy than to make sure
tunnel_id and tunnel_dst are read only once and checked in the egress path.

Cc: stable@vger.kernel.org
Fixes: 11538d039ac6 ("bridge: vlan dst_metadata hooks in ingress and egress paths")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

bridge: Fix possible races between assigning rx_handler_data and setting IFF_BRIDGE_PORT bit

2021-04-29T22:33:17+00:00

There is a crash in the function br_get_link_af_size_filtered,
as the port_exists(dev) is true and the rx_handler_data of dev is NULL.
But the rx_handler_data of dev is correct saved in vmcore.

The oops looks something like:
 ...
 pc : br_get_link_af_size_filtered+0x28/0x1c8 [bridge]
 ...
 Call trace:
  br_get_link_af_size_filtered+0x28/0x1c8 [bridge]
  if_nlmsg_size+0x180/0x1b0
  rtnl_calcit.isra.12+0xf8/0x148
  rtnetlink_rcv_msg+0x334/0x370
  netlink_rcv_skb+0x64/0x130
  rtnetlink_rcv+0x28/0x38
  netlink_unicast+0x1f0/0x250
  netlink_sendmsg+0x310/0x378
  sock_sendmsg+0x4c/0x70
  __sys_sendto+0x120/0x150
  __arm64_sys_sendto+0x30/0x40
  el0_svc_common+0x78/0x130
  el0_svc_handler+0x38/0x78
  el0_svc+0x8/0xc

In br_add_if(), we found there is no guarantee that
assigning rx_handler_data to dev->rx_handler_data
will before setting the IFF_BRIDGE_PORT bit of priv_flags.
So there is a possible data competition:

CPU 0:                                                        CPU 1:
(RCU read lock)                                               (RTNL lock)
rtnl_calcit()                                                 br_add_slave()
  if_nlmsg_size()                                               br_add_if()
    br_get_link_af_size_filtered()                              -> netdev_rx_handler_register
                                                                    ...
                                                                    // The order is not guaranteed
      ...                                                           -> dev->priv_flags |= IFF_BRIDGE_PORT;
      // The IFF_BRIDGE_PORT bit of priv_flags has been set
      -> if (br_port_exists(dev)) {
        // The dev->rx_handler_data has NOT been assigned
        -> p = br_port_get_rcu(dev);
        ....
                                                                    -> rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
                                                                     ...

Fix it in br_get_link_af_size_filtered, using br_port_get_check_rcu() and checking the return value.

Signed-off-by: Zhang Zhengming 
Reviewed-by: Zhao Lei 
Reviewed-by: Wang Xiaogang 
Suggested-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bridge: mcast: fix broken length + header check for MRDv6 Adv.

2021-04-27T21:02:06+00:00

The IPv6 Multicast Router Advertisements parsing has the following two
issues:

For one thing, ICMPv6 MRD Advertisements are smaller than ICMPv6 MLD
messages (ICMPv6 MRD Adv.: 8 bytes vs. ICMPv6 MLDv1/2: >= 24 bytes,
assuming MLDv2 Reports with at least one multicast address entry).
When ipv6_mc_check_mld_msg() tries to parse an Multicast Router
Advertisement its MLD length check will fail - and it will wrongly
return -EINVAL, even if we have a valid MRD Advertisement. With the
returned -EINVAL the bridge code will assume a broken packet and will
wrongly discard it, potentially leading to multicast packet loss towards
multicast routers.

The second issue is the MRD header parsing in
br_ip6_multicast_mrd_rcv(): It wrongly checks for an ICMPv6 header
immediately after the IPv6 header (IPv6 next header type). However
according to RFC4286, section 2 all MRD messages contain a Router Alert
option (just like MLD). So instead there is an IPv6 Hop-by-Hop option
for the Router Alert between the IPv6 and ICMPv6 header, again leading
to the bridge wrongly discarding Multicast Router Advertisements.

To fix these two issues, introduce a new return value -ENODATA to
ipv6_mc_check_mld() to indicate a valid ICMPv6 packet with a hop-by-hop
option which is not an MLD but potentially an MRD packet. This also
simplifies further parsing in the bridge code, as ipv6_mc_check_mld()
already fully checks the ICMPv6 header and hop-by-hop option.

These issues were found and fixed with the help of the mrdisc tool
(https://github.com/troglobit/mrdisc).

Fixes: 4b3087c7e37f ("bridge: Snoop Multicast Router Advertisements")
Signed-off-by: Linus Lüssing 
Signed-off-by: David S. Miller

netfilter: allow to turn off xtables compat layer

2021-04-26T16:16:56+00:00

The compat layer needs to parse untrusted input (the ruleset)
to translate it to a 64bit compatible format.

We had a number of bugs in this department in the past, so allow users
to turn this feature off.

Add CONFIG_NETFILTER_XTABLES_COMPAT kconfig knob and make it default to y
to keep existing behaviour.

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: ebtables: remove the 3 ebtables pointers from struct net

2021-04-26T01:20:07+00:00

ebtables stores the table internal data (what gets passed to the
ebt_do_table() interpreter) in struct net.

nftables keeps the internal interpreter format in pernet lists
and passes it via the netfilter core infrastructure (priv pointer).

Do the same for ebtables: the nf_hook_ops are duplicated via kmemdup,
then the ops->priv pointer is set to the table that is being registered.

After that, the netfilter core passes this table info to the hookfn.

This allows to remove the pointers from struct net.

Same pattern can be applied to ip/ip6/arptables.

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

net: bridge: fix error in br_multicast_add_port when CONFIG_NET_SWITCHDEV=n

2021-04-21T20:13:33+00:00

When CONFIG_NET_SWITCHDEV is disabled, the shim for switchdev_port_attr_set
inside br_mc_disabled_update returns -EOPNOTSUPP. This is not caught,
and propagated to the caller of br_multicast_add_port, preventing ports
from joining the bridge.

Reported-by: Christian Borntraeger 
Fixes: ae1ea84b33da ("net: bridge: propagate error code and extack from br_mc_disabled_update")
Signed-off-by: Vladimir Oltean 
Acked-by: Florian Fainelli 
Tested-by: Christian Borntraeger 
Acked-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-04-17T18:08:07+00:00

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
 - keep the ZC code, drop the code related to reinit
net/bridge/netfilter/ebtables.c
 - fix build after move to net_generic

Signed-off-by: Jakub Kicinski

net: bridge: switchdev: include local flag in FDB notifications

2021-04-16T22:15:45+00:00

As explained in bugfix commit 6ab4c3117aec ("net: bridge: don't notify
switchdev for local FDB addresses") as well as in this discussion:
https://lore.kernel.org/netdev/20210117193009.io3nungdwuzmo5f7@skbuf/

the switchdev notifiers for FDB entries managed to have a zero-day bug,
which was that drivers would not know what to do with local FDB entries,
because they were not told that they are local. The bug fix was to
simply not notify them of those addresses.

Let us now add the 'is_local' bit to bridge FDB entries, and make all
drivers ignore these entries by their own choice.

Co-developed-by: Tobias Waldekranz 
Signed-off-by: Tobias Waldekranz 
Signed-off-by: Vladimir Oltean 
Reviewed-by: Grygorii Strashko 
Reviewed-by: Ido Schimmel 
Signed-off-by: David S. Miller

net: bridge: switchdev: refactor br_switchdev_fdb_notify

2021-04-16T22:15:45+00:00

Instead of having to add more and more arguments to
br_switchdev_fdb_call_notifiers, get rid of it and build the info
struct directly in br_switchdev_fdb_notify.

Signed-off-by: Tobias Waldekranz 
Reviewed-by: Vladimir Oltean 
Signed-off-by: Vladimir Oltean 
Reviewed-by: Ido Schimmel 
Signed-off-by: David S. Miller