linux.git/net/bridge/br_device.c, branch v5.4.63

net: bridge: deny dev_set_mac_address() when unregistering

2019-12-18T15:08:19+00:00

[ Upstream commit c4b4c421857dc7b1cf0dccbd738472360ff2cd70 ]

We have an interesting memory leak in the bridge when it is being
unregistered and is a slave to a master device which would change the
mac of its slaves on unregister (e.g. bond, team). This is a very
unusual setup but we do end up leaking 1 fdb entry because
dev_set_mac_address() would cause the bridge to insert the new mac address
into its table after all fdbs are flushed, i.e. after dellink() on the
bridge has finished and we call NETDEV_UNREGISTER the bond/team would
release it and will call dev_set_mac_address() to restore its original
address and that in turn will add an fdb in the bridge.
One fix is to check for the bridge dev's reg_state in its
ndo_set_mac_address callback and return an error if the bridge is not in
NETREG_REGISTERED.

Easy steps to reproduce:
 1. add bond in mode != A/B
 2. add any slave to the bond
 3. add bridge dev as a slave to the bond
 4. destroy the bridge device

Trace:
 unreferenced object 0xffff888035c4d080 (size 128):
   comm "ip", pid 4068, jiffies 4296209429 (age 1413.753s)
   hex dump (first 32 bytes):
     41 1d c9 36 80 88 ff ff 00 00 00 00 00 00 00 00  A..6............
     d2 19 c9 5e 3f d7 00 00 00 00 00 00 00 00 00 00  ...^?...........
   backtrace:
     [<00000000ddb525dc>] kmem_cache_alloc+0x155/0x26f
     [<00000000633ff1e0>] fdb_create+0x21/0x486 [bridge]
     [<0000000092b17e9c>] fdb_insert+0x91/0xdc [bridge]
     [<00000000f2a0f0ff>] br_fdb_change_mac_address+0xb3/0x175 [bridge]
     [<000000001de02dbd>] br_stp_change_bridge_id+0xf/0xff [bridge]
     [<00000000ac0e32b1>] br_set_mac_address+0x76/0x99 [bridge]
     [<000000006846a77f>] dev_set_mac_address+0x63/0x9b
     [<00000000d30738fc>] __bond_release_one+0x3f6/0x455 [bonding]
     [<00000000fc7ec01d>] bond_netdev_event+0x2f2/0x400 [bonding]
     [<00000000305d7795>] notifier_call_chain+0x38/0x56
     [<0000000028885d4a>] call_netdevice_notifiers+0x1e/0x23
     [<000000008279477b>] rollback_registered_many+0x353/0x6a4
     [<0000000018ef753a>] unregister_netdevice_many+0x17/0x6f
     [<00000000ba854b7a>] rtnl_delete_link+0x3c/0x43
     [<00000000adf8618d>] rtnl_dellink+0x1dc/0x20a
     [<000000009b6395fd>] rtnetlink_rcv_msg+0x23d/0x268

Fixes: 43598813386f ("bridge: add local MAC address to forwarding table (v2)")
Reported-by: syzbot+2add91c08eb181fea1bf@syzkaller.appspotmail.com
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: core: add generic lockdep keys

2019-10-24T21:53:48+00:00

Some interface types could be nested.
(VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, VIRT_WIFI, VXLAN, etc..)
These interface types should set lockdep class because, without lockdep
class key, lockdep always warn about unexisting circular locking.

In the current code, these interfaces have their own lockdep class keys and
these manage itself. So that there are so many duplicate code around the
/driver/net and /net/.
This patch adds new generic lockdep keys and some helper functions for it.

This patch does below changes.
a) Add lockdep class keys in struct net_device
   - qdisc_running, xmit, addr_list, qdisc_busylock
   - these keys are used as dynamic lockdep key.
b) When net_device is being allocated, lockdep keys are registered.
   - alloc_netdev_mqs()
c) When net_device is being free'd llockdep keys are unregistered.
   - free_netdev()
d) Add generic lockdep key helper function
   - netdev_register_lockdep_key()
   - netdev_unregister_lockdep_key()
   - netdev_update_lockdep_key()
e) Remove unnecessary generic lockdep macro and functions
f) Remove unnecessary lockdep code of each interfaces.

After this patch, each interface modules don't need to maintain
their lockdep keys.

Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller

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

2019-06-07T18:00:14+00:00

Some ISDN files that got removed in net-next had some changes
done in mainline, take the removals.

Signed-off-by: David S. Miller

netfilter: bridge: add connection tracking system

2019-05-30T21:18:18+00:00

This patch adds basic connection tracking support for the bridge,
including initial IPv4 support.

This patch register two hooks to deal with the bridge forwarding path,
one from the bridge prerouting hook to call nf_conntrack_in(); and
another from the bridge postrouting hook to confirm the entry.

The conntrack bridge prerouting hook defragments packets before passing
them to nf_conntrack_in() to look up for an existing entry, otherwise a
new entry is allocated and it is attached to the skbuff. The conntrack
bridge postrouting hook confirms new conntrack entries, ie. if this is
the first packet seen, then it adds the entry to the hashtable and (if
needed) it refragments the skbuff into the original fragments, leaving
the geometry as is if possible. Exceptions are linearized skbuffs, eg.
skbuffs that are passed up to nfqueue and conntrack helpers, as well as
cloned skbuff for the local delivery (eg. tcpdump), also in case of
bridge port flooding (cloned skbuff too).

The packet defragmentation is done through the ip_defrag() call.  This
forces us to save the bridge control buffer, reset the IP control buffer
area and then restore it after call. This function also bumps the IP
fragmentation statistics, it would be probably desiderable to have
independent statistics for the bridge defragmentation/refragmentation.
The maximum fragment length is stored in the control buffer and it is
used to refragment the skbuff from the postrouting path.

The new fraglist splitter and fragment transformer APIs are used to
implement the bridge refragmentation code. The br_ip_fragment() function
drops the packet in case the maximum fragment size seen is larger than
the output port MTU.

This patchset follows the principle that conntrack should not drop
packets, so users can do it through policy via invalid state matching.

Like br_netfilter, there is no refragmentation for packets that are
passed up for local delivery, ie. prerouting -> input path. There are
calls to nf_reset() already in several spots in the stack since time ago
already, eg. af_packet, that show that skbuff fraglist handling from the
netif_rx path is supported already.

The helpers are called from the postrouting hook, before confirmation,
from there we may see packet floods to bridge ports. Then, although
unlikely, this may result in exercising the helpers many times for each
clone. It would be good to explore how to pass all the packets in a list
to the conntrack hook to do this handle only once for this case.

Thanks to Florian Westphal for handing me over an initial patchset
version to add support for conntrack bridge.

Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: David S. Miller

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman

bridge: support for ndo_fdb_get

2018-12-16T22:42:34+00:00

This patch implements ndo_fdb_get for the bridge
fdb.

Signed-off-by: Roopa Prabhu 
Acked-by: Nikolay Aleksandrov 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller

net: bridge: convert multicast to generic rhashtable

2018-12-06T01:01:51+00:00

The bridge multicast code currently uses a custom resizable hashtable
which predates the generic rhashtable interface. It has many
shortcomings compared and duplicates functionality that is presently
available via the generic rhashtable, so this patch removes the custom
rhashtable implementation in favor of the kernel's generic rhashtable.
The hash maximum is kept and the rhashtable's size is used to do a loose
check if it's reached in which case we revert to the old behaviour and
disable further bridge multicast processing. Also now we can support any
hash maximum, doesn't need to be a power of 2.

v3: add non-rcu br_mdb_get variant and use it where multicast_lock is
    held to avoid RCU splat, drop hash_max function and just set it
    directly

v2: handle when IGMP snooping is undefined, add br_mdb_init/uninit
    placeholders

Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

netpoll: allow cleanup to be synchronous

2018-10-20T00:01:43+00:00

This fixes a problem introduced by:
commit 2cde6acd49da ("netpoll: Fix __netpoll_rcu_free so that it can hold the rtnl lock")

When using netconsole on a bond, __netpoll_cleanup can asynchronously
recurse multiple times, each __netpoll_free_async call can result in
more __netpoll_free_async's. This means there is now a race between
cleanup_work queues on multiple netpoll_info's on multiple devices and
the configuration of a new netpoll. For example if a netconsole is set
to enable 0, reconfigured, and enable 1 immediately, this netconsole
will likely not work.

Given the reason for __netpoll_free_async is it can be called when rtnl
is not locked, if it is locked, we should be able to execute
synchronously. It appears to be locked everywhere it's called from.

Generalize the design pattern from the teaming driver for current
callers of __netpoll_free_async.

CC: Neil Horman 
CC: "David S. Miller" 
Signed-off-by: Debabrata Banerjee 
Signed-off-by: David S. Miller

net: bridge: convert mtu_set_by_user to a bit

2018-09-26T17:04:23+00:00

Convert the last remaining bool option to a bit thus reducing the overall
net_bridge size further by 8 bytes.

Signed-off-by: Nikolay Aleksandrov 
Reviewed-by: Stephen Hemminger 
Signed-off-by: David S. Miller

net: bridge: convert neigh_suppress_enabled option to a bit

2018-09-26T17:04:23+00:00

Convert the neigh_suppress_enabled option to a bit.

Signed-off-by: Nikolay Aleksandrov 
Reviewed-by: Stephen Hemminger 
Signed-off-by: David S. Miller