linux-stable.git/net/bridge, branch v5.4.129

net: bridge: fix vlan tunnel dst refcnt when egressing

2021-06-23T12:41:30+00:00

commit cfc579f9d89af4ada58c69b03bcaa4887840f3b3 upstream.

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 
Signed-off-by: Greg Kroah-Hartman

net: bridge: fix vlan tunnel dst null pointer dereference

2021-06-23T12:41:30+00:00

commit 58e2071742e38f29f051b709a5cca014ba51166f upstream.

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 
Signed-off-by: Greg Kroah-Hartman

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

2021-05-22T09:38:29+00:00

[ Upstream commit 59259ff7a81b9eb6213891c6451221e567f8f22f ]

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 
Signed-off-by: Sasha Levin

net: bridge: when suppression is enabled exclude RARP packets

2021-05-19T08:08:21+00:00

[ Upstream commit 0353b4a96b7a9f60fe20d1b3ebd4931a4085f91c ]

Recently we had an interop issue where RARP packets got suppressed with
bridge neigh suppression enabled, but the check in the code was meant to
suppress GARP. Exclude RARP packets from it which would allow some VMWare
setups to work, to quote the report:
"Those RARP packets usually get generated by vMware to notify physical
switches when vMotion occurs. vMware may use random sip/tip or just use
sip=tip=0. So the RARP packet sometimes get properly flooded by the vtep
and other times get dropped by the logic"

Reported-by: Amer Abdalamer 
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

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

2021-05-14T07:44:32+00:00

[ Upstream commit 99014088156cd78867d19514a0bc771c4b86b93b ]

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 
Signed-off-by: Sasha Levin

netfilter: bridge: add pre_exit hooks for ebtable unregistration

2021-04-21T10:56:16+00:00

commit 7ee3c61dcd28bf6e290e06ad382f13511dc790e9 upstream.

Just like ip/ip6/arptables, the hooks have to be removed, then
synchronize_rcu() has to be called to make sure no more packets are being
processed before the ruleset data is released.

Place the hook unregistration in the pre_exit hook, then call the new
ebtables pre_exit function from there.

Years ago, when first netns support got added for netfilter+ebtables,
this used an older (now removed) netfilter hook unregister API, that did
a unconditional synchronize_rcu().

Now that all is done with call_rcu, ebtable_{filter,nat,broute} pernet exit
handlers may free the ebtable ruleset while packets are still in flight.

This can only happens on module removal, not during netns exit.

The new function expects the table name, not the table struct.

This is because upcoming patch set (targeting -next) will remove all
net->xt.{nat,filter,broute}_table instances, this makes it necessary
to avoid external references to those member variables.

The existing APIs will be converted, so follow the upcoming scheme of
passing name + hook type instead.

Fixes: aee12a0a3727e ("ebtables: remove nf_hook_register usage")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

net: bridge: use switchdev for port flags set through sysfs too

2021-03-07T11:20:43+00:00

commit 8043c845b63a2dd88daf2d2d268a33e1872800f0 upstream.

Looking through patchwork I don't see that there was any consensus to
use switchdev notifiers only in case of netlink provided port flags but
not sysfs (as a sort of deprecation, punishment or anything like that),
so we should probably keep the user interface consistent in terms of
functionality.

http://patchwork.ozlabs.org/project/netdev/patch/20170605092043.3523-3-jiri@resnulli.us/
http://patchwork.ozlabs.org/project/netdev/patch/20170608064428.4785-3-jiri@resnulli.us/

Fixes: 3922285d96e7 ("net: bridge: Add support for offloading port attributes")
Signed-off-by: Vladimir Oltean 
Acked-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: bridge: Fix a warning when del bridge sysfs

2021-02-23T14:02:25+00:00

[ Upstream commit 989a1db06eb18ff605377eec87e18d795e0ec74b ]

I got a warining report:

br_sysfs_addbr: can't create group bridge4/bridge
------------[ cut here ]------------
sysfs group 'bridge' not found for kobject 'bridge4'
WARNING: CPU: 2 PID: 9004 at fs/sysfs/group.c:279 sysfs_remove_group fs/sysfs/group.c:279 [inline]
WARNING: CPU: 2 PID: 9004 at fs/sysfs/group.c:279 sysfs_remove_group+0x153/0x1b0 fs/sysfs/group.c:270
Modules linked in: iptable_nat
...
Call Trace:
  br_dev_delete+0x112/0x190 net/bridge/br_if.c:384
  br_dev_newlink net/bridge/br_netlink.c:1381 [inline]
  br_dev_newlink+0xdb/0x100 net/bridge/br_netlink.c:1362
  __rtnl_newlink+0xe11/0x13f0 net/core/rtnetlink.c:3441
  rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3500
  rtnetlink_rcv_msg+0x385/0x980 net/core/rtnetlink.c:5562
  netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2494
  netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
  netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1330
  netlink_sendmsg+0x793/0xc80 net/netlink/af_netlink.c:1919
  sock_sendmsg_nosec net/socket.c:651 [inline]
  sock_sendmsg+0x139/0x170 net/socket.c:671
  ____sys_sendmsg+0x658/0x7d0 net/socket.c:2353
  ___sys_sendmsg+0xf8/0x170 net/socket.c:2407
  __sys_sendmsg+0xd3/0x190 net/socket.c:2440
  do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

In br_device_event(), if the bridge sysfs fails to be added,
br_device_event() should return error. This can prevent warining
when removing bridge sysfs that do not exist.

Fixes: bb900b27a2f4 ("bridge: allow creating bridge devices with netlink")
Reported-by: Hulk Robot 
Signed-off-by: Wang Hai 
Tested-by: Nikolay Aleksandrov 
Acked-by: Nikolay Aleksandrov 
Link: https://lore.kernel.org/r/20201211122921.40386-1-wanghai38@huawei.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

bridge: Fix a deadlock when enabling multicast snooping

2020-12-21T12:27:04+00:00

[ Upstream commit 851d0a73c90e6c8c63fef106c6c1e73df7e05d9d ]

When enabling multicast snooping, bridge module deadlocks on multicast_lock
if 1) IPv6 is enabled, and 2) there is an existing querier on the same L2
network.

The deadlock was caused by the following sequence: While holding the lock,
br_multicast_open calls br_multicast_join_snoopers, which eventually causes
IP stack to (attempt to) send out a Listener Report (in igmp6_join_group).
Since the destination Ethernet address is a multicast address, br_dev_xmit
feeds the packet back to the bridge via br_multicast_rcv, which in turn
calls br_multicast_add_group, which then deadlocks on multicast_lock.

The fix is to move the call br_multicast_join_snoopers outside of the
critical section. This works since br_multicast_join_snoopers only deals
with IP and does not modify any multicast data structures of the bridge,
so there's no need to hold the lock.

Steps to reproduce:
1. sysctl net.ipv6.conf.all.force_mld_version=1
2. have another querier
3. ip link set dev bridge type bridge mcast_snooping 0 && \
   ip link set dev bridge type bridge mcast_snooping 1 < deadlock >

A typical call trace looks like the following:

[  936.251495]  _raw_spin_lock+0x5c/0x68
[  936.255221]  br_multicast_add_group+0x40/0x170 [bridge]
[  936.260491]  br_multicast_rcv+0x7ac/0xe30 [bridge]
[  936.265322]  br_dev_xmit+0x140/0x368 [bridge]
[  936.269689]  dev_hard_start_xmit+0x94/0x158
[  936.273876]  __dev_queue_xmit+0x5ac/0x7f8
[  936.277890]  dev_queue_xmit+0x10/0x18
[  936.281563]  neigh_resolve_output+0xec/0x198
[  936.285845]  ip6_finish_output2+0x240/0x710
[  936.290039]  __ip6_finish_output+0x130/0x170
[  936.294318]  ip6_output+0x6c/0x1c8
[  936.297731]  NF_HOOK.constprop.0+0xd8/0xe8
[  936.301834]  igmp6_send+0x358/0x558
[  936.305326]  igmp6_join_group.part.0+0x30/0xf0
[  936.309774]  igmp6_group_added+0xfc/0x110
[  936.313787]  __ipv6_dev_mc_inc+0x1a4/0x290
[  936.317885]  ipv6_dev_mc_inc+0x10/0x18
[  936.321677]  br_multicast_open+0xbc/0x110 [bridge]
[  936.326506]  br_multicast_toggle+0xec/0x140 [bridge]

Fixes: 4effd28c1245 ("bridge: join all-snoopers multicast address")
Signed-off-by: Joseph Huang 
Acked-by: Nikolay Aleksandrov 
Link: https://lore.kernel.org/r/20201204235628.50653-1-Joseph.Huang@garmin.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

net: bridge: vlan: fix error return code in __vlan_add()

2020-12-21T12:27:03+00:00

[ Upstream commit ee4f52a8de2c6f78b01f10b4c330867d88c1653a ]

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: f8ed289fab84 ("bridge: vlan: use br_vlan_(get|put)_master to deal with refcounts")
Reported-by: Hulk Robot 
Signed-off-by: Zhang Changzhong 
Acked-by: Nikolay Aleksandrov 
Link: https://lore.kernel.org/r/1607071737-33875-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman