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: 28172739f0 ("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>
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: c1a8311679 ("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>
Small conflict around locking in rxrpc_process_event() -
channel_lock moved to bundle in next, while state lock
needs _bh() from net.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is correcting NETLINK br_fill_ifinfo() to be able to
handle 'filter_mask' with multiple flags asserted.
Fixes: 36a8e8e265 ("bridge: Extend br_fill_ifinfo to return MPR status")
Signed-off-by: Henrik Bjoernlund <henrik.bjoernlund@microchip.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Suggested-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Rejecting non-native endian BTF overlapped with the addition
of support for it.
The rest were more simple overlapping changes, except the
renesas ravb binding update, which had to follow a file
move as well as a YAML conversion.
Signed-off-by: David S. Miller <davem@davemloft.net>
Functions related to nested interface infrastructure such as
netdev_walk_all_{ upper | lower }_dev() pass both private functions
and "data" pointer to handle their own things.
At this point, the data pointer type is void *.
In order to make it easier to expand common variables and functions,
this new netdev_nested_priv structure is added.
In the following patch, a new member variable will be added into this
struct to fix the lockdep issue.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a user-space software manages fdb entries externally it should
set the ext_learn flag which marks the fdb entry as externally managed
and avoids expiring it (they're treated as static fdbs). Unfortunately
on events where fdb entries are flushed (STP down, netlink fdb flush
etc) these fdbs are also deleted automatically by the bridge. That in turn
causes trouble for the managing user-space software (e.g. in MLAG setups
we lose remote fdb entries on port flaps).
These entries are completely externally managed so we should avoid
automatically deleting them, the only exception are offloaded entries
(i.e. BR_FDB_ADDED_BY_EXT_LEARN + BR_FDB_OFFLOADED). They are flushed as
before.
Fixes: eb100e0e24 ("net: bridge: allow to add externally learned entries from user-space")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We should remove a group from the sg_port hash only if it's an S,G
entry. This makes it correct and more symmetric with group add. Also
since *,G groups are not added to that hash we can hide a bug.
Fixes: 085b53c8be ("net: bridge: mcast: add sg_port rhashtable")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to avoid forwarding to ports in MCAST_INCLUDE filter mode when the
mdst entry is a *,G or when the port has the blocked flag.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since host joins are considered as EXCLUDE {} joins we need to reflect
that in all of *,G ports' S,G entries. Since the S,Gs can have
host_joined == true only set automatically we can safely set it to false
when removing all automatically added entries upon S,G delete.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When excluding S,G entries we need a way to block a particular S,G,port.
The new port group flag is managed based on the source's timer as per
RFCs 3376 and 3810. When a source expires and its port group is in
EXCLUDE mode, it will be blocked.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to handle group filter mode transitions and initial state.
To change a port group's INCLUDE -> EXCLUDE mode (or when we have added
a new port group in EXCLUDE mode) we need to add that port to all of
*,G ports' S,G entries for proper replication. When the EXCLUDE state is
changed from IGMPv3 report, br_multicast_fwd_filter_exclude() must be
called after the source list processing because the assumption is that
all of the group's S,G entries will be created before transitioning to
EXCLUDE mode, i.e. most importantly its blocked entries will already be
added so it will not get automatically added to them.
The transition EXCLUDE -> INCLUDE happens only when a port group timer
expires, it requires us to remove that port from all of *,G ports' S,G
entries where it was automatically added previously.
Finally when we are adding a new S,G entry we must add all of *,G's
EXCLUDE ports to it.
In order to distinguish automatically added *,G EXCLUDE ports we have a
new port group flag - MDB_PG_FLAGS_STAR_EXCL.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds support for automatic install of S,G mdb entries based
on the port group's source list and the source entry's timer.
Once installed the S,G will be used when forwarding packets if the
approprate multicast/mld versions are set. A new source flag called
BR_SGRP_F_INSTALLED denotes if the source has a forwarding mdb entry
installed.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To speedup S,G forward handling we need to be able to quickly find out
if a port is a member of an S,G group. To do that add a global S,G port
rhashtable with key: source addr, group addr, protocol, vid (all br_ip
fields) and port pointer.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to be able to differentiate between pg entries created by
user-space and the kernel when we start generating S,G entries for
IGMPv3/MLDv2's fast path. User-space entries are created by default as
RTPROT_STATIC and the kernel entries are RTPROT_KERNEL. Later we can
allow user-space to provide the entry rt_protocol so we can
differentiate between who added the entries specifically (e.g. clag,
admin, frr etc).
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If (S,G) entries are enabled (igmpv3/mldv2) then look them up first. If
there isn't a present (S,G) entry then try to find (*,G).
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add new mdb attributes (MDBE_ATTR_SOURCE for setting,
MDBA_MDB_EATTR_SOURCE for dumping) to allow add/del and dump of mdb
entries with a source address (S,G). New S,G entries are created with
filter mode of MCAST_INCLUDE. The same attributes are used for IPv4 and
IPv6, they're validated and parsed based on their protocol.
S,G host joined entries which are added by user are not allowed yet.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since the MDB add/del code expects an exact struct br_mdb_entry we can't
really add any extensions, thus add a new nested attribute at the level of
MDBA_SET_ENTRY called MDBA_SET_ENTRY_ATTRS which will be used to pass
all new options via netlink attributes. This patch doesn't change
anything functionally since the new attribute is not used yet, only
parsed.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since now we have src in br_ip, u no longer makes sense so rename
it to dst. No functional changes.
v2: fix build with CONFIG_BATMAN_ADV_MCAST
CC: Marek Lindner <mareklindner@neomailbox.ch>
CC: Simon Wunderlich <sw@simonwunderlich.de>
CC: Antonio Quartulli <a@unstable.cc>
CC: Sven Eckelmann <sven@narfation.org>
CC: b.a.t.m.a.n@lists.open-mesh.org
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that we have src and dst in br_ip it is logical to use the src field
for the cases where we need to work with a source address such as
querier source address and group source address.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass and use extack all the way down to br_mdb_add_group().
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To avoid doing duplicate device checks and searches (the same were done
in br_mdb_add and __br_mdb_add) pass the already found port to __br_mdb_add
and pull the bridge's netif_running and enabled multicast checks to
br_mdb_add. This would also simplify the future extack errors.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can drop the pr_info() calls and just use extack to return a
meaningful error to user-space when br_mdb_parse() fails.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Two minor conflicts:
1) net/ipv4/route.c, adding a new local variable while
moving another local variable and removing it's
initial assignment.
2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
One pretty prints the port mode differently, whilst another
changes the driver to try and obtain the port mode from
the port node rather than the switch node.
Signed-off-by: David S. Miller <davem@davemloft.net>
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: 7582f5b70f ("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>
Drop repeated words in net/bridge/.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: Nikolay Aleksandrov <nikolay@nvidia.com>
Cc: bridge@lists.linux-foundation.org
Signed-off-by: David S. Miller <davem@davemloft.net>
When we're handling TO_EXCLUDE report in EXCLUDE filter mode we should
not ignore the return value of __grp_src_toex_excl() as we'll miss
sending notifications about group changes.
Fixes: 5bf1e00b68 ("net: bridge: mcast: support for IGMPV3/MLDv2 CHANGE_TO_INCLUDE/EXCLUDE report")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
so the switchdev can notifiy the bridge to flush non-permanent fdb entries
for this port. This is useful whenever the hardware fdb of the switchdev
is reset, but the netdev and the bridgeport are not deleted.
Note that this has the same effect as the IFLA_BRPORT_FLUSH attribute.
CC: Jiri Pirko <jiri@resnulli.us>
CC: Ivan Vecera <ivecera@redhat.com>
CC: Roopa Prabhu <roopa@nvidia.com>
CC: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each MDB entry is encoded in a nested netlink attribute called
'MDBA_MDB_ENTRY'. In turn, this attribute contains another nested
attributed called 'MDBA_MDB_ENTRY_INFO', which encodes a single port
group entry within the MDB entry.
The cited commit added the ability to restart a dump from a specific
port group entry. However, on failure to add a port group entry to the
dump the entire MDB entry (stored in 'nest2') is removed, resulting in
missing port group entries.
Fix this by finalizing the MDB entry with the partial list of already
encoded port group entries.
Fixes: 5205e919c9 ("net: bridge: mcast: add support for src list and filter mode dumping")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for net-next:
1) Rewrite inner header IPv6 in ICMPv6 messages in ip6t_NPT,
from Michael Zhou.
2) do_ip_vs_set_ctl() dereferences uninitialized value,
from Peilin Ye.
3) Support for userdata in tables, from Jose M. Guisado.
4) Do not increment ct error and invalid stats at the same time,
from Florian Westphal.
5) Remove ct ignore stats, also from Florian.
6) Add ct stats for clash resolution, from Florian Westphal.
7) Bump reference counter bump on ct clash resolution only,
this is safe because bucket lock is held, again from Florian.
8) Use ip_is_fragment() in xt_HMARK, from YueHaibing.
9) Add wildcard support for nft_socket, from Balazs Scheidler.
10) Remove superfluous IPVS dependency on iptables, from
Yaroslav Bolyukin.
11) Remove unused definition in ebt_stp, from Wang Hai.
12) Replace CONFIG_NFT_CHAIN_NAT_{IPV4,IPV6} by CONFIG_NFT_NAT
in selftests/net, from Fabian Frederick.
13) Add userdata support for nft_object, from Jose M. Guisado.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Stephen reported the following warning:
net/bridge/br_multicast.c: In function 'br_multicast_find_port':
net/bridge/br_multicast.c:1818:21: warning: unused variable 'br' [-Wunused-variable]
1818 | struct net_bridge *br = mp->br;
| ^~
It happens due to bridge's mlock_dereference() when lockdep isn't defined.
Silence the warning by annotating the variable as __maybe_unused.
Fixes: 0436862e41 ("net: bridge: mcast: support for IGMPv3/MLDv2 ALLOW_NEW_SOURCES report")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
BPDU_TYPE_TCN is never used after it was introduced.
So better to remove it.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since each entry type has timers that can be running simultaneously we need
to make sure that entries are not freed before their timers have finished.
In order to do that generalize the src gc work to mcast gc work and use a
callback to free the entries (mdb, port group or src).
v3: add IPv6 support
v2: force mcast gc on port del to make sure all port group timers have
finished before freeing the bridge port
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When an IGMPv3/MLDv2 query is received and we're operating in such mode
then we need to avoid updating group timers if the suppress flag is set.
Also we should update only timers for groups in exclude mode.
v3: add IPv6/MLDv2 support
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We already have all necessary helpers, so process IGMPV3/MLDv2
BLOCK_OLD_SOURCES as per the RFCs.
v3: add IPv6/MLDv2 support
v2: directly do flag bit operations
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In order to process IGMPV3/MLDv2 CHANGE_TO_INCLUDE/EXCLUDE report types we
need new helpers which allow us to mark entries based on their timer
state and to query only marked entries.
v3: add IPv6/MLDv2 support, fix other_query checks
v2: directly do flag bit operations
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In order to process IGMPV3/MLDv2_MODE_IS_INCLUDE/EXCLUDE report types we
need some new helpers which allow us to set/clear flags for all current
entries and later delete marked entries after the report sources have been
processed.
v3: add IPv6/MLDv2 support
v2: drop flag helpers and directly do flag bit operations
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch adds handling for the ALLOW_NEW_SOURCES IGMPv3/MLDv2 report
types and limits them only when multicast_igmp_version == 3 or
multicast_mld_version == 2 respectively. Now that IGMPv3/MLDv2 handling
functions will be managing timers we need to delay their activation, thus
a new argument is added which controls if the timer should be updated.
We also disable host IGMPv3/MLDv2 handling as it's not yet implemented and
could cause inconsistent group state, the host can only join a group as
EXCLUDE {} or leave it.
v4: rename update_timer to igmpv2_mldv1 and use the passed value from
br_multicast_add_group's callers
v3: Add IPv6/MLDv2 support
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If an expired port group is in EXCLUDE mode, then we have to turn it
into INCLUDE mode, remove all srcs with zero timer and finally remove
the group itself if there are no more srcs with an active timer.
For IGMPv2 use there would be no sources, so this will reduce to just
removing the group as before.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We have to use mdb and port entries when sending mdb notifications in
order to fill in all group attributes properly. Before this change we
would've used a fake br_mdb_entry struct to fill in only partial
information about the mdb. Now we can also reuse the mdb dump fill
function and thus have only a single central place which fills the mdb
attributes.
v3: add IPv6 support
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This change is in preparation for using the mdb port group entries when
sending a notification, so their full state and additional attributes can
be filled in.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We need to be able to retransmit group-specific and group-and-source
specific queries. The new timer takes care of those.
v3: add IPv6 support
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Allows br_multicast_alloc_query to build queries with the port group's
source lists and sends a query for sources over and under lmqt when
necessary as per RFCs 3376 and 3810 with the suppress flag set
appropriately.
v3: add IPv6 support
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Support per port group src list (address and timer) and filter mode
dumping. Protected by either multicast_lock or rcu.
v3: add IPv6 support
v2: require RCU or multicast_lock to traverse src groups
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Initial functions for group source lists which are needed for IGMPv3
and MLDv2 include/exclude lists. Both IPv4 and IPv6 sources are supported.
User-added mdb entries are created with exclude filter mode, we can
extend that later to allow user-supplied mode. When group src entries
are deleted, they're freed from a workqueue to make sure their timers
are not still running. Source entries are protected by the multicast_lock
and rcu. The number of src groups per port group is limited to 32.
v4: use the new port group del function directly
add igmpv2/mldv1 bool to denote if the entry was added in those
modes, it will later replace the old update_timer bool
v3: add IPv6 support
v2: allow src groups to be traversed under rcu
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In order to avoid future errors and reduce code duplication we should
factor out the port group del sequence. This allows us to have one
function which takes care of all details when removing a port group.
v4: set pg's fast leave flag when deleting due to fast leave
move the patch before adding source lists
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Before this patch we'd need 2 cache lines for fast-path, now all used
fields are in the first cache line.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Change places that open-code NLA_POLICY_EXACT_LEN() to
use the macro instead, giving us flexibility in how we
handle the details of the macro.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
syzkaller reports splat:
------------[ cut here ]------------
Buffer overflow detected (80 < 137)!
Call Trace:
do_ebt_get_ctl+0x2b4/0x790 net/bridge/netfilter/ebtables.c:2317
nf_getsockopt+0x72/0xd0 net/netfilter/nf_sockopt.c:116
ip_getsockopt net/ipv4/ip_sockglue.c:1778 [inline]
caused by a copy-to-user with a too-large "*len" value.
This adds a argument check on *len just like in the non-compat version
of the handler.
Before the "Fixes" commit, the reproducer fails with -EINVAL as
expected:
1. core calls the "compat" getsockopt version
2. compat getsockopt version detects the *len value is possibly
in 64-bit layout (*len != compat_len)
3. compat getsockopt version delegates everything to native getsockopt
version
4. native getsockopt rejects invalid *len
-> compat handler only sees len == sizeof(compat_struct) for GET_ENTRIES.
After the refactor, event sequence is:
1. getsockopt calls "compat" version (len != native_len)
2. compat version attempts to copy *len bytes, where *len is random
value from userspace
Fixes: fc66de8e16 ("netfilter/ebtables: clean up compat {get, set}sockopt handling")
Reported-by: syzbot+5accb5c62faa1d346480@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Heiner Kallweit