Commit Graph

16 Commits

Author SHA1 Message Date
Linus Lüssing 2b5fbba583 net: bridge: mcast: fix broken length + header check for MRDv6 Adv.
[ 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 <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-20 16:08:01 +08:00
Florian Westphal f492ae7573 netfilter: bridge: add pre_exit hooks for ebtable unregistration
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 <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20 16:07:12 +08:00
Vladimir Oltean 593486bce0 net: bridge: use switchdev for port flags set through sysfs too
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 <vladimir.oltean@nxp.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-12 12:52:45 +08:00
Wang Hai 866f20cac1 net: bridge: Fix a warning when del bridge sysfs
[ 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 <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Tested-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20201211122921.40386-1-wanghai38@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-12 12:52:07 +08:00
Joseph Huang be867ca371 bridge: Fix a deadlock when enabling multicast snooping
[ 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 <Joseph.Huang@garmin.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20201204235628.50653-1-Joseph.Huang@garmin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:42:17 +08:00
Zhang Changzhong 9d0db45c76 net: bridge: vlan: fix error return code in __vlan_add()
[ 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 <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/1607071737-33875-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:42:16 +08:00
Antoine Tenart f51dcb3640 netfilter: bridge: reset skb->pkt_type after NF_INET_POST_ROUTING traversal
[ Upstream commit 44f64f23bae2f0fad25503bc7ab86cd08d04cd47 ]

Netfilter changes PACKET_OTHERHOST to PACKET_HOST before invoking the
hooks as, while it's an expected value for a bridge, routing expects
PACKET_HOST. The change is undone later on after hook traversal. This
can be seen with pairs of functions updating skb>pkt_type and then
reverting it to its original value:

For hook NF_INET_PRE_ROUTING:
  setup_pre_routing / br_nf_pre_routing_finish

For hook NF_INET_FORWARD:
  br_nf_forward_ip / br_nf_forward_finish

But the third case where netfilter does this, for hook
NF_INET_POST_ROUTING, the packet type is changed in br_nf_post_routing
but never reverted. A comment says:

  /* We assume any code from br_dev_queue_push_xmit onwards doesn't care
   * about the value of skb->pkt_type. */

But when having a tunnel (say vxlan) attached to a bridge we have the
following call trace:

  br_nf_pre_routing
  br_nf_pre_routing_ipv6
     br_nf_pre_routing_finish
  br_nf_forward_ip
     br_nf_forward_finish
  br_nf_post_routing           <- pkt_type is updated to PACKET_HOST
     br_nf_dev_queue_xmit      <- but not reverted to its original value
  vxlan_xmit
     vxlan_xmit_one
        skb_tunnel_check_pmtu  <- a check on pkt_type is performed

In this specific case, this creates issues such as when an ICMPv6 PTB
should be sent back. When CONFIG_BRIDGE_NETFILTER is enabled, the PTB
isn't sent (as skb_tunnel_check_pmtu checks if pkt_type is PACKET_HOST
and returns early).

If the comment is right and no one cares about the value of
skb->pkt_type after br_dev_queue_push_xmit (which isn't true), resetting
it to its original value should be safe.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20201123174902.622102-1-atenart@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:41:54 +08:00
Heiner Kallweit 5423e245c3 net: bridge: add missing counters to ndo_get_stats64 callback
[ Upstream commit 7a30ecc9237681bb125cbd30eee92bef7e86293d ]

In br_forward.c and br_input.c fields dev->stats.tx_dropped and
dev->stats.multicast are populated, but they are ignored in
ndo_get_stats64.

Fixes: 28172739f0a2 ("net: fix 64 bit counters on 32 bit arches")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/58ea9963-77ad-a7cf-8dfd-fc95ab95f606@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:41:05 +08:00
Timothée COCAULT 9748d74a6e netfilter: ebtables: Fixes dropping of small packets in bridge nat
[ Upstream commit 63137bc5882a1882c553d389fdeeeace86ee1741 ]

Fixes an error causing small packets to get dropped. skb_ensure_writable
expects the second parameter to be a length in the ethernet payload.=20
If we want to write the ethernet header (src, dst), we should pass 0.
Otherwise, packets with small payloads (< ETH_ALEN) will get dropped.

Fixes: c1a831167901 ("netfilter: bridge: convert skb_make_writable to skb_ensure_writable")
Signed-off-by: Timothée COCAULT <timothee.cocault@orange.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-16 16:39:05 +08:00
Vladimir Oltean a2bf26175f net: bridge: br_vlan_get_pvid_rcu() should dereference the VLAN group under RCU
[ Upstream commit 99f62a746066fa436aa15d4606a538569540db08 ]

When calling the RCU brother of br_vlan_get_pvid(), lockdep warns:

=============================
WARNING: suspicious RCU usage
5.9.0-rc3-01631-g13c17acb8e38-dirty #814 Not tainted
-----------------------------
net/bridge/br_private.h:1054 suspicious rcu_dereference_protected() usage!

Call trace:
 lockdep_rcu_suspicious+0xd4/0xf8
 __br_vlan_get_pvid+0xc0/0x100
 br_vlan_get_pvid_rcu+0x78/0x108

The warning is because br_vlan_get_pvid_rcu() calls nbp_vlan_group()
which calls rtnl_dereference() instead of rcu_dereference(). In turn,
rtnl_dereference() calls rcu_dereference_protected() which assumes
operation under an RCU write-side critical section, which obviously is
not the case here. So, when the incorrect primitive is used to access
the RCU-protected VLAN group pointer, READ_ONCE() is not used, which may
cause various unexpected problems.

I'm sad to say that br_vlan_get_pvid() and br_vlan_get_pvid_rcu() cannot
share the same implementation. So fix the bug by splitting the 2
functions, and making br_vlan_get_pvid_rcu() retrieve the VLAN groups
under proper locking annotations.

Fixes: 7582f5b70f9a ("bridge: add br_vlan_get_pvid_rcu()")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:36:26 +08:00
Florian Westphal fb26c256c1 netfilter: avoid ipv6 -> nf_defrag_ipv6 module dependency
[ Upstream commit 2404b73c3f1a5f15726c6ecd226b56f6f992767f ]

nf_ct_frag6_gather is part of nf_defrag_ipv6.ko, not ipv6 core.

The current use of the netfilter ipv6 stub indirections  causes a module
dependency between ipv6 and nf_defrag_ipv6.

This prevents nf_defrag_ipv6 module from being removed because ipv6 can't
be unloaded.

Remove the indirection and always use a direct call.  This creates a
depency from nf_conntrack_bridge to nf_defrag_ipv6 instead:

modinfo nf_conntrack
depends:        nf_conntrack,nf_defrag_ipv6,bridge

.. and nf_conntrack already depends on nf_defrag_ipv6 anyway.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-16 16:35:05 +08:00
Linus Lüssing bcd3ad6246 bridge: mcast: Fix MLD2 Report IPv6 payload length check
[ Upstream commit 5fc6266af7b427243da24f3443a50cd4584aac06 ]

Commit e57f61858b7c ("net: bridge: mcast: fix stale nsrcs pointer in
igmp3/mld2 report handling") introduced a bug in the IPv6 header payload
length check which would potentially lead to rejecting a valid MLD2 Report:

The check needs to take into account the 2 bytes for the "Number of
Sources" field in the "Multicast Address Record" before reading it.
And not the size of a pointer to this field.

Fixes: e57f61858b7c ("net: bridge: mcast: fix stale nsrcs pointer in igmp3/mld2 report handling")
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:31:42 +08:00
Thomas Martitz ab5fd1c7d6 net: bridge: enfore alignment for ethernet address
[ Upstream commit db7202dec92e6caa2706c21d6fc359af318bde2e ]

The eth_addr member is passed to ether_addr functions that require
2-byte alignment, therefore the member must be properly aligned
to avoid unaligned accesses.

The problem is in place since the initial merge of multicast to unicast:
commit 6db6f0eae6052b70885562e1733896647ec1d807 bridge: multicast to unicast

Fixes: 6db6f0eae605 ("bridge: multicast to unicast")
Cc: Roopa Prabhu <roopa@cumulusnetworks.com>
Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Felix Fietkau <nbd@nbd.name>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Martitz <t.martitz@avm.de>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:30:46 +08:00
Ido Schimmel 210a4306ad bridge: Avoid infinite loop when suppressing NS messages with invalid options
[ Upstream commit 53fc685243bd6fb90d90305cea54598b78d3cbfc ]

When neighbor suppression is enabled the bridge device might reply to
Neighbor Solicitation (NS) messages on behalf of remote hosts.

In case the NS message includes the "Source link-layer address" option
[1], the bridge device will use the specified address as the link-layer
destination address in its reply.

To avoid an infinite loop, break out of the options parsing loop when
encountering an option with length zero and disregard the NS message.

This is consistent with the IPv6 ndisc code and RFC 4886 which states
that "Nodes MUST silently discard an ND packet that contains an option
with length zero" [2].

[1] https://tools.ietf.org/html/rfc4861#section-4.3
[2] https://tools.ietf.org/html/rfc4861#section-4.6

Fixes: ed842faeb2bd ("bridge: suppress nd pkts on BR_NEIGH_SUPPRESS ports")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Alla Segal <allas@mellanox.com>
Tested-by: Alla Segal <allas@mellanox.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:28:54 +08:00
Michael Braun 84bea0c9d6 netfilter: nft_reject_bridge: enable reject with bridge vlan
commit e9c284ec4b41c827f4369973d2792992849e4fa5 upstream.

Currently, using the bridge reject target with tagged packets
results in untagged packets being sent back.

Fix this by mirroring the vlan id as well.

Fixes: 85f5b3086a04 ("netfilter: bridge: add reject support")
Signed-off-by: Michael Braun <michael-dev@fami-braun.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:28:40 +08:00
Kaixu Xia 590eaf1fec Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
2021-03-16 11:01:34 +08:00