linux-stable.git/net/bridge, branch v4.20.4

netfilter: ebtables: account ebt_table_info to kmemcg

2019-01-22T20:09:56+00:00

commit e2c8d550a973bb34fc28bc8d0ec996f84562fb8a upstream.

The [ip,ip6,arp]_tables use x_tables_info internally and the underlying
memory is already accounted to kmemcg. Do the same for ebtables. The
syzbot, by using setsockopt(EBT_SO_SET_ENTRIES), was able to OOM the
whole system from a restricted memcg, a potential DoS.

By accounting the ebt_table_info, the memory used for ebt_table_info can
be contained within the memcg of the allocating process. However the
lifetime of ebt_table_info is independent of the allocating process and
is tied to the network namespace. So, the oom-killer will not be able to
relieve the memory pressure due to ebt_table_info memory. The memory for
ebt_table_info is allocated through vmalloc. Currently vmalloc does not
handle the oom-killed allocating process correctly and one large
allocation can bypass memcg limit enforcement. So, with this patch,
at least the small allocations will be contained. For large allocations,
we need to fix vmalloc.

Reported-by: syzbot+7713f3aa67be76b1552c@syzkaller.appspotmail.com
Signed-off-by: Shakeel Butt 
Reviewed-by: Kirill Tkhai 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

net: bridge: fix a bug on using a neighbour cache entry without checking its state

2019-01-22T20:09:48+00:00

[ Upstream commit 4c84edc11b76590859b1e45dd676074c59602dc4 ]

When handling DNAT'ed packets on a bridge device, the neighbour cache entry
from lookup was used without checking its state. It means that a cache entry
in the NUD_STALE state will be used directly instead of entering the NUD_DELAY
state to confirm the reachability of the neighbor.

This problem becomes worse after commit 2724680bceee ("neigh: Keep neighbour
cache entries if number of them is small enough."), since all neighbour cache
entries in the NUD_STALE state will be kept in the neighbour table as long as
the number of cache entries does not exceed the value specified in gc_thresh1.

This commit validates the state of a neighbour cache entry before using
the entry.

Signed-off-by: JianJhen Chen 
Reviewed-by: JinLin Chen 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: bridge: fix vlan stats use-after-free on destruction

2018-11-18T05:38:44+00:00

Syzbot reported a use-after-free of the global vlan context on port vlan
destruction. When I added per-port vlan stats I missed the fact that the
global vlan context can be freed before the per-port vlan rcu callback.
There're a few different ways to deal with this, I've chosen to add a
new private flag that is set only when per-port stats are allocated so
we can directly check it on destruction without dereferencing the global
context at all. The new field in net_bridge_vlan uses a hole.

v2: cosmetic change, move the check to br_process_vlan_info where the
    other checks are done
v3: add change log in the patch, add private (in-kernel only) flags in a
    hole in net_bridge_vlan struct and use that instead of mixing
    user-space flags with private flags

Fixes: 9163a0fc1f0c ("net: bridge: add support for per-port vlan stats")
Reported-by: syzbot+04681da557a0e49a52e5@syzkaller.appspotmail.com
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bridge: remove ipv6 zero address check in mcast queries

2018-10-29T02:18:09+00:00

Recently a check was added which prevents marking of routers with zero
source address, but for IPv6 that cannot happen as the relevant RFCs
actually forbid such packets:
RFC 2710 (MLDv1):
"To be valid, the Query message MUST
 come from a link-local IPv6 Source Address, be at least 24 octets
 long, and have a correct MLD checksum."

Same goes for RFC 3810.

And also it can be seen as a requirement in ipv6_mc_check_mld_query()
which is used by the bridge to validate the message before processing
it. Thus any queries with :: source address won't be processed anyway.
So just remove the check for zero IPv6 source address from the query
processing function.

Fixes: 5a2de63fd1a5 ("bridge: do not add port to router list when receives query with source 0.0.0.0")
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

bridge: do not add port to router list when receives query with source 0.0.0.0

2018-10-26T23:01:23+00:00

Based on RFC 4541, 2.1.1.  IGMP Forwarding Rules

  The switch supporting IGMP snooping must maintain a list of
  multicast routers and the ports on which they are attached.  This
  list can be constructed in any combination of the following ways:

  a) This list should be built by the snooping switch sending
     Multicast Router Solicitation messages as described in IGMP
     Multicast Router Discovery [MRDISC].  It may also snoop
     Multicast Router Advertisement messages sent by and to other
     nodes.

  b) The arrival port for IGMP Queries (sent by multicast routers)
     where the source address is not 0.0.0.0.

We should not add the port to router list when receives query with source
0.0.0.0.

Reported-by: Ying Xu 
Signed-off-by: Hangbin Liu 
Acked-by: Nikolay Aleksandrov 
Acked-by: Roopa Prabhu 
Signed-off-by: David S. Miller

Merge tag 'docs-4.20' of git://git.lwn.net/linux

2018-10-24T17:01:11+00:00

Pull documentation updates from Jonathan Corbet:
 "This is a fairly typical cycle for documentation. There's some welcome
  readability improvements for the formatted output, some LICENSES
  updates including the addition of the ISC license, the removal of the
  unloved and unmaintained 00-INDEX files, the deprecated APIs document
  from Kees, more MM docs from Mike Rapoport, and the usual pile of typo
  fixes and corrections"

* tag 'docs-4.20' of git://git.lwn.net/linux: (41 commits)
  docs: Fix typos in histogram.rst
  docs: Introduce deprecated APIs list
  kernel-doc: fix declaration type determination
  doc: fix a typo in adding-syscalls.rst
  docs/admin-guide: memory-hotplug: remove table of contents
  doc: printk-formats: Remove bogus kobject references for device nodes
  Documentation: preempt-locking: Use better example
  dm flakey: Document "error_writes" feature
  docs/completion.txt: Fix a couple of punctuation nits
  LICENSES: Add ISC license text
  LICENSES: Add note to CDDL-1.0 license that it should not be used
  docs/core-api: memory-hotplug: add some details about locking internals
  docs/core-api: rename memory-hotplug-notifier to memory-hotplug
  docs: improve readability for people with poorer eyesight
  yama: clarify ptrace_scope=2 in Yama documentation
  docs/vm: split memory hotplug notifier description to Documentation/core-api
  docs: move memory hotplug description into admin-guide/mm
  doc: Fix acronym "FEKEK" in ecryptfs
  docs: fix some broken documentation references
  iommu: Fix passthrough option documentation
  ...

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

bridge: switchdev: Allow clearing FDB entry offload indication

2018-10-18T00:45:08+00:00

Currently, an FDB entry only ceases being offloaded when it is deleted.
This changes with VxLAN encapsulation.

Devices capable of performing VxLAN encapsulation usually have only one
FDB table, unlike the software data path which has two - one in the
bridge driver and another in the VxLAN driver.

Therefore, bridge FDB entries pointing to a VxLAN device are only
offloaded if there is a corresponding entry in the VxLAN FDB.

Allow clearing the offload indication in case the corresponding entry
was deleted from the VxLAN FDB.

Signed-off-by: Ido Schimmel 
Reviewed-by: Petr Machata 
Signed-off-by: David S. Miller

net: bridge: fix a possible memory leak in __vlan_add

2018-10-16T05:53:52+00:00

After per-port vlan stats, vlan stats should be released
when fail to add vlan

Fixes: 9163a0fc1f0c0 ("net: bridge: add support for per-port vlan stats")
CC: bridge@lists.linux-foundation.org
cc: Nikolay Aleksandrov 
CC: Roopa Prabhu 
Signed-off-by: Zhang Yu 
Signed-off-by: Li RongQing 
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bridge: add support for per-port vlan stats

2018-10-12T17:18:58+00:00

This patch adds an option to have per-port vlan stats instead of the
default global stats. The option can be set only when there are no port
vlans in the bridge since we need to allocate the stats if it is set
when vlans are being added to ports (and respectively free them
when being deleted). Also bump RTNL_MAX_TYPE as the bridge is the
largest user of options. The current stats design allows us to add
these without any changes to the fast-path, it all comes down to
the per-vlan stats pointer which, if this option is enabled, will
be allocated for each port vlan instead of using the global bridge-wide
one.

CC: bridge@lists.linux-foundation.org
CC: Roopa Prabhu 
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller