ip_tables_net_ops and udplite6_net_ops create and destroy /proc entries.
xt_net_ops does nothing.

So, we are able to mark them async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Exit methods calls inet_frags_exit_net() with global ip6_frags
as argument. So, after we make the pernet_operations async,
a pair of exit methods may be called to iterate this hash table.
Since there is inet_frag_worker(), which already may work
in parallel with inet_frags_exit_net(), and it can make the same
cleanup, that inet_frags_exit_net() does, it's safe. So we may
mark these pernet_operations as async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These pernet_operations register and unregister tables
and lists for packets forwarding. All of the entities
are per-net. Init methods makes simple initializations,
and since net is not visible for foreigners at the time
it is working, it can't race with anything. Exit method
is executed when there are only local devices, and there
mustn't be packets in-flight. Also, it looks like no one
pernet_operations want to send ipv6 packets to foreign
net. The same reasons are for ipv6_addr_label_ops and
ip6_segments_ops. So, we are able to mark all them as
async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These pernet_operations create sysctl tables and
initialize net::xfrm.xfrm6_dst_ops used for routing.
It doesn't look like another pernet_operations send
ipv6 packets to foreign net namespaces, so it should
be safe to mark the pernet_operations as async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These pernet_operations create and destroy /proc entries.
ip6_fl_purge() makes almost the same actions as timer
ip6_fl_gc_timer does, and as it can be executed in parallel
with ip6_fl_purge(), two parallel ip6_fl_purge() may be
executed. So, we can mark it async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These pernet_operations only register and unregister /proc
entries, so it's possible to mark them async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These pernet_operations create and destroy sysctl tables.
They are not touched by another net pernet_operations.
So, it's possible to execute them in parallel with others.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These pernet_operations create and destroy net::ipv6.tcp_sk
socket, which is used in tcp_v6_send_response() only. It looks
like foreign pernet_operations don't want to set ipv6 connection
inside destroyed net, so this socket may be created in destroyed
in parallel with anything else. inet_twsk_purge() is also safe
for that, as described in patch for tcp_sk_ops. So, it's possible
to mark them as async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These pernet_operations register and unregister
net::ipv6.fib6_rules_ops, which are used for
routing. It looks like there are no pernet_operations,
which send ipv6 packages to another net, so we
are able to mark them as async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net->ipv6.peers is dereferenced in three places via inet_getpeer_v6(),
and it's used to handle skb. All the users of inet_getpeer_v6() do not
look like be able to be called from foreign net pernet_operations, so
we may mark them as async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net: Convert raw6_net_ops, udplite6_net_ops, ipv6_proc_ops, if6_proc_net_ops and ip6_route_net_late_ops

These pernet_operations create and destroy /proc entries
and safely may be converted and safely may be mark as async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These pernet_operations create and destroy net::ipv6.icmp_sk
socket, used to send ICMP or error reply.

Nobody can dereference the socket to handle a packet before
net is initialized, as there is no routing; nobody can do
that in parallel with exit, as all of devices are moved
to init_net or destroyed and there are no packets it-flight.
So, it's possible to mark these pernet_operations as async.

The same for ndisc_net_ops and for igmp6_net_ops. The last
one also creates and destroys /proc entries.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These pernet_operations create and destroy /proc entries,
populate and depopulate net::rules_ops and multiroute table.
All the structures are pernet, and they are not touched
by foreign net pernet_operations. So, it's possible to mark
them async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

init method initializes sysctl defaults, allocates
percpu arrays and creates /proc entries.
exit method reverts the above.

There are no pernet_operations, which are interested
in the above entities of foreign net namespace, so
inet6_net_ops are able to be marked as async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPv4 uses set_lwt_redirect to set the lwtunnel redirect functions as
needed. Move it to lwtunnel.h as lwtunnel_set_redirect and change
IPv6 to also use it.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

배석진 reported that in some situations, packets for a given 5-tuple
end up being processed by different CPUS.

This involves RPS, and fragmentation.

배석진 is seeing packet drops when a SYN_RECV request socket is
moved into ESTABLISH state. Other states are protected by socket lock.

This is caused by a CPU losing the race, and simply not caring enough.

Since this seems to occur frequently, we can do better and perform
a second lookup.

Note that all needed memory barriers are already in the existing code,
thanks to the spin_lock()/spin_unlock() pair in inet_ehash_insert()
and reqsk_put(). The second lookup must find the new socket,
unless it has already been accepted and closed by another cpu.

Note that the fragmentation could be avoided in the first place by
use of a correct TCP MSS option in the SYN{ACK} packet, but this
does not mean we can not be more robust.

Many thanks to 배석진 for a very detailed analysis.
Reported-by: N배석진 <soukjin.bae@samsung.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These pernet_operations (un)register sysctl, which
are not touched by anybody else.

So, it's safe to make them async.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: NAndrei Vagin <avagin@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Changes since v1:
Added changes in these files:
    drivers/infiniband/hw/usnic/usnic_transport.c
    drivers/staging/lustre/lnet/lnet/lib-socket.c
    drivers/target/iscsi/iscsi_target_login.c
    drivers/vhost/net.c
    fs/dlm/lowcomms.c
    fs/ocfs2/cluster/tcp.c
    security/tomoyo/network.c

Before:
All these functions either return a negative error indicator,
or store length of sockaddr into "int *socklen" parameter
and return zero on success.

"int *socklen" parameter is awkward. For example, if caller does not
care, it still needs to provide on-stack storage for the value
it does not need.

None of the many FOO_getname() functions of various protocols
ever used old value of *socklen. They always just overwrite it.

This change drops this parameter, and makes all these functions, on success,
return length of sockaddr. It's always >= 0 and can be differentiated
from an error.

Tests in callers are changed from "if (err)" to "if (err < 0)", where needed.

rpc_sockname() lost "int buflen" parameter, since its only use was
to be passed to kernel_getsockname() as &buflen and subsequently
not used in any way.

Userspace API is not changed.

    text    data     bss      dec     hex filename
30108430 2633624  873672 33615726 200ef6e vmlinux.before.o
30108109 2633612  873672 33615393 200ee21 vmlinux.o
Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
CC: David S. Miller <davem@davemloft.net>
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-bluetooth@vger.kernel.org
CC: linux-decnet-user@lists.sourceforge.net
CC: linux-wireless@vger.kernel.org
CC: linux-rdma@vger.kernel.org
CC: linux-sctp@vger.kernel.org
CC: linux-nfs@vger.kernel.org
CC: linux-x25@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tracepoint tcp_send_reset requires a full socket to work. However, it
may be called when in TCP_TIME_WAIT:

        case TCP_TW_RST:
                tcp_v6_send_reset(sk, skb);
                inet_twsk_deschedule_put(inet_twsk(sk));
                goto discard_it;

To avoid this problem, this patch checks the socket with sk_fullsock()
before calling trace_tcp_send_reset().

Fixes: c24b14c4 ("tcp: add tracepoint trace_tcp_send_reset")
Signed-off-by: NSong Liu <songliubraving@fb.com>
Reviewed-by: NLawrence Brakmo <brakmo@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Because of differences in how ipv4 and ipv6 handle fib lookups,
verification of nexthops with onlink flag need to default to the main
table rather than the local table used by IPv4. As it stands an
address within a connected route on device 1 can be used with
onlink on device 2. Updating the table properly rejects the route
due to the egress device mismatch.

Update the extack message as well to show it could be a device
mismatch for the nexthop spec.

Fixes: fc1e64e1 ("net/ipv6: Add support for onlink flag")
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Verification of nexthops with onlink flag need to handle unreachable
routes. The lookup is only intended to validate the gateway address
is not a local address and if the gateway resolves the egress device
must match the given device. Hence, hitting any default reject route
is ok.

Fixes: fc1e64e1 ("net/ipv6: Add support for onlink flag")
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This macro is only used by net/ipv6/mcast.c, but there is no reason
why it must be BUILD_BUG_ON_NULL().

Replace it with BUILD_BUG_ON_ZERO(), and remove BUILD_BUG_ON_NULL()
definition from <linux/build_bug.h>.

Link: http://lkml.kernel.org/r/1515121833-3174-3-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Every flow_offload entry is added into the table twice. Because of this,
rhashtable_free_and_destroy can't be used, since it would call kfree for
each flow_offload object twice.

This patch cleans up the flowtable via nf_flow_table_iterate() to
schedule removal of entries by setting on the dying bit, then there is
an explicitly invocation of the garbage collector to release resources.

Based on patch from Felix Fietkau.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

When an erspan tunnel device receives an erpsan packet with different
tunnel metadata (ex: version, index, hwid, direction), existing code
overwrites the tunnel device's erspan configuration with the received
packet's metadata.  The patch fixes it.

Fixes: 1a66a836 ("gre: add collect_md mode to ERSPAN tunnel")
Fixes: f551c91d ("net: erspan: introduce erspan v2 for ip_gre")
Fixes: ef7baf5e ("ip6_gre: add ip6 erspan collect_md mode")
Fixes: 94d7d8f2 ("ip6_gre: add erspan v2 support")
Signed-off-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit d350a823 ("net: erspan: create erspan metadata uapi header")
moves the erspan 'version' in front of the 'struct erspan_md2' for
later extensibility reason.  This breaks the existing erspan metadata
extraction code because the erspan_md2 then has a 4-byte offset
to between the erspan_metadata and erspan_base_hdr.  This patch
fixes it.

Fixes: 1a66a836 ("gre: add collect_md mode to ERSPAN tunnel")
Fixes: ef7baf5e ("ip6_gre: add ip6 erspan collect_md mode")
Fixes: 1d7e2ed2 ("net: erspan: refactor existing erspan code")
Signed-off-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

config NF_FLOW_TABLE depends on NETFILTER_INGRESS. If users forget to
enable this toggle, flowtable registration fails with EOPNOTSUPP.

Moreover, turn 'select NF_FLOW_TABLE' in every flowtable family flavour
into dependency instead, otherwise this new dependency on
NETFILTER_INGRESS causes a warning. This also allows us to remove the
explicit dependency between family flowtables <-> NF_TABLES and
NF_CONNTRACK, given they depend on the NF_FLOW_TABLE core that already
expresses the general dependencies for this new infrastructure.

Moreover, NF_FLOW_TABLE_INET depends on NF_FLOW_TABLE_IPV4 and
NF_FLOWTABLE_IPV6, which already depends on NF_FLOW_TABLE. So we can get
rid of direct dependency with NF_FLOW_TABLE.

In general, let's avoid 'select', it just makes things more complicated.
Reported-by: NJohn Crispin <john@phrozen.org>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Failures were seen in ICMPv6 fragmentation timeout tests if they were
run after the RFC2460 failure tests. Kernel was not sending out the
ICMPv6 fragment reassembly time exceeded packet after the fragmentation
reassembly timeout of 1 minute had elapsed.

This happened because the frag queue was not released if an error in
IPv6 fragmentation header was detected by RFC2460.

Fixes: 83f1999c ("netfilter: ipv6: nf_defrag: Pass on packets to stack per RFC2460")
Signed-off-by: NSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Syzbot reported several deadlocks in the netfilter area caused by
rtnl lock and socket lock being acquired with a different order on
different code paths, leading to backtraces like the following one:

======================================================
WARNING: possible circular locking dependency detected
4.15.0-rc9+ #212 Not tainted
------------------------------------------------------
syzkaller041579/3682 is trying to acquire lock:
  (sk_lock-AF_INET6){+.+.}, at: [<000000008775e4dd>] lock_sock
include/net/sock.h:1463 [inline]
  (sk_lock-AF_INET6){+.+.}, at: [<000000008775e4dd>]
do_ipv6_setsockopt.isra.8+0x3c5/0x39d0 net/ipv6/ipv6_sockglue.c:167

but task is already holding lock:
  (rtnl_mutex){+.+.}, at: [<000000004342eaa9>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (rtnl_mutex){+.+.}:
        __mutex_lock_common kernel/locking/mutex.c:756 [inline]
        __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
        mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
        rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
        register_netdevice_notifier+0xad/0x860 net/core/dev.c:1607
        tee_tg_check+0x1a0/0x280 net/netfilter/xt_TEE.c:106
        xt_check_target+0x22c/0x7d0 net/netfilter/x_tables.c:845
        check_target net/ipv6/netfilter/ip6_tables.c:538 [inline]
        find_check_entry.isra.7+0x935/0xcf0
net/ipv6/netfilter/ip6_tables.c:580
        translate_table+0xf52/0x1690 net/ipv6/netfilter/ip6_tables.c:749
        do_replace net/ipv6/netfilter/ip6_tables.c:1165 [inline]
        do_ip6t_set_ctl+0x370/0x5f0 net/ipv6/netfilter/ip6_tables.c:1691
        nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
        nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
        ipv6_setsockopt+0x115/0x150 net/ipv6/ipv6_sockglue.c:928
        udpv6_setsockopt+0x45/0x80 net/ipv6/udp.c:1422
        sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978
        SYSC_setsockopt net/socket.c:1849 [inline]
        SyS_setsockopt+0x189/0x360 net/socket.c:1828
        entry_SYSCALL_64_fastpath+0x29/0xa0

-> #0 (sk_lock-AF_INET6){+.+.}:
        lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914
        lock_sock_nested+0xc2/0x110 net/core/sock.c:2780
        lock_sock include/net/sock.h:1463 [inline]
        do_ipv6_setsockopt.isra.8+0x3c5/0x39d0 net/ipv6/ipv6_sockglue.c:167
        ipv6_setsockopt+0xd7/0x150 net/ipv6/ipv6_sockglue.c:922
        udpv6_setsockopt+0x45/0x80 net/ipv6/udp.c:1422
        sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978
        SYSC_setsockopt net/socket.c:1849 [inline]
        SyS_setsockopt+0x189/0x360 net/socket.c:1828
        entry_SYSCALL_64_fastpath+0x29/0xa0

other info that might help us debug this:

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(rtnl_mutex);
                                lock(sk_lock-AF_INET6);
                                lock(rtnl_mutex);
   lock(sk_lock-AF_INET6);

  *** DEADLOCK ***

1 lock held by syzkaller041579/3682:
  #0:  (rtnl_mutex){+.+.}, at: [<000000004342eaa9>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

The problem, as Florian noted, is that nf_setsockopt() is always
called with the socket held, even if the lock itself is required only
for very tight scopes and only for some operation.

This patch addresses the issues moving the lock_sock() call only
where really needed, namely in ipv*_getorigdst(), so that nf_setsockopt()
does not need anymore to acquire both locks.

Fixes: 22265a5c ("netfilter: xt_TEE: resolve oif using netdevice notifiers")
Reported-by: syzbot+a4c2dc980ac1af699b36@syzkaller.appspotmail.com
Suggested-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

When we dump the ip6mr mfc entries via proc, we initialize an iterator
with the table to dump but we don't clear the cache pointer which might
be initialized from a prior read on the same descriptor that ended. This
can result in lock imbalance (an unnecessary unlock) leading to other
crashes and hangs. Clear the cache pointer like ipmr does to fix the issue.
Thanks for the reliable reproducer.

Here's syzbot's trace:
 WARNING: bad unlock balance detected!
 4.15.0-rc3+ #128 Not tainted
 syzkaller971460/3195 is trying to release lock (mrt_lock) at:
 [<000000006898068d>] ipmr_mfc_seq_stop+0xe1/0x130 net/ipv6/ip6mr.c:553
 but there are no more locks to release!

 other info that might help us debug this:
 1 lock held by syzkaller971460/3195:
  #0:  (&p->lock){+.+.}, at: [<00000000744a6565>] seq_read+0xd5/0x13d0
 fs/seq_file.c:165

 stack backtrace:
 CPU: 1 PID: 3195 Comm: syzkaller971460 Not tainted 4.15.0-rc3+ #128
 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
 Google 01/01/2011
 Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x257 lib/dump_stack.c:53
  print_unlock_imbalance_bug+0x12f/0x140 kernel/locking/lockdep.c:3561
  __lock_release kernel/locking/lockdep.c:3775 [inline]
  lock_release+0x5f9/0xda0 kernel/locking/lockdep.c:4023
  __raw_read_unlock include/linux/rwlock_api_smp.h:225 [inline]
  _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255
  ipmr_mfc_seq_stop+0xe1/0x130 net/ipv6/ip6mr.c:553
  traverse+0x3bc/0xa00 fs/seq_file.c:135
  seq_read+0x96a/0x13d0 fs/seq_file.c:189
  proc_reg_read+0xef/0x170 fs/proc/inode.c:217
  do_loop_readv_writev fs/read_write.c:673 [inline]
  do_iter_read+0x3db/0x5b0 fs/read_write.c:897
  compat_readv+0x1bf/0x270 fs/read_write.c:1140
  do_compat_preadv64+0xdc/0x100 fs/read_write.c:1189
  C_SYSC_preadv fs/read_write.c:1209 [inline]
  compat_SyS_preadv+0x3b/0x50 fs/read_write.c:1203
  do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
  do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
  entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125
 RIP: 0023:0xf7f73c79
 RSP: 002b:00000000e574a15c EFLAGS: 00000292 ORIG_RAX: 000000000000014d
 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 0000000020a3afb0
 RDX: 0000000000000001 RSI: 0000000000000067 RDI: 0000000000000000
 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 BUG: sleeping function called from invalid context at lib/usercopy.c:25
 in_atomic(): 1, irqs_disabled(): 0, pid: 3195, name: syzkaller971460
 INFO: lockdep is turned off.
 CPU: 1 PID: 3195 Comm: syzkaller971460 Not tainted 4.15.0-rc3+ #128
 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
 Google 01/01/2011
 Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x257 lib/dump_stack.c:53
  ___might_sleep+0x2b2/0x470 kernel/sched/core.c:6060
  __might_sleep+0x95/0x190 kernel/sched/core.c:6013
  __might_fault+0xab/0x1d0 mm/memory.c:4525
  _copy_to_user+0x2c/0xc0 lib/usercopy.c:25
  copy_to_user include/linux/uaccess.h:155 [inline]
  seq_read+0xcb4/0x13d0 fs/seq_file.c:279
  proc_reg_read+0xef/0x170 fs/proc/inode.c:217
  do_loop_readv_writev fs/read_write.c:673 [inline]
  do_iter_read+0x3db/0x5b0 fs/read_write.c:897
  compat_readv+0x1bf/0x270 fs/read_write.c:1140
  do_compat_preadv64+0xdc/0x100 fs/read_write.c:1189
  C_SYSC_preadv fs/read_write.c:1209 [inline]
  compat_SyS_preadv+0x3b/0x50 fs/read_write.c:1203
  do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
  do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
  entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125
 RIP: 0023:0xf7f73c79
 RSP: 002b:00000000e574a15c EFLAGS: 00000292 ORIG_RAX: 000000000000014d
 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 0000000020a3afb0
 RDX: 0000000000000001 RSI: 0000000000000067 RDI: 0000000000000000
 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 WARNING: CPU: 1 PID: 3195 at lib/usercopy.c:26 _copy_to_user+0xb5/0xc0
 lib/usercopy.c:26
Reported-by: Nsyzbot <bot+eceb3204562c41a438fa1f2335e0fe4f6886d669@syzkaller.appspotmail.com>
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Heiner reported a lockdep splat [1]

This is caused by attempting GFP_KERNEL allocation while RCU lock is
held and BH blocked.

We believe that addrconf_verify_rtnl() could run for a long period,
so instead of using GFP_ATOMIC here as Ido suggested, we should break
the critical section and restart it after the allocation.

[1]
[86220.125562] =============================
[86220.125586] WARNING: suspicious RCU usage
[86220.125612] 4.15.0-rc7-next-20180110+ #7 Not tainted
[86220.125641] -----------------------------
[86220.125666] kernel/sched/core.c:6026 Illegal context switch in RCU-bh read-side critical section!
[86220.125711]
               other info that might help us debug this:

[86220.125755]
               rcu_scheduler_active = 2, debug_locks = 1
[86220.125792] 4 locks held by kworker/0:2/1003:
[86220.125817]  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.125895]  #1:  ((addr_chk_work).work){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.125959]  #2:  (rtnl_mutex){+.+.}, at: [<00000000b06d9510>] rtnl_lock+0x12/0x20
[86220.126017]  #3:  (rcu_read_lock_bh){....}, at: [<00000000aef52299>] addrconf_verify_rtnl+0x1e/0x510 [ipv6]
[86220.126111]
               stack backtrace:
[86220.126142] CPU: 0 PID: 1003 Comm: kworker/0:2 Not tainted 4.15.0-rc7-next-20180110+ #7
[86220.126185] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015
[86220.126250] Workqueue: ipv6_addrconf addrconf_verify_work [ipv6]
[86220.126288] Call Trace:
[86220.126312]  dump_stack+0x70/0x9e
[86220.126337]  lockdep_rcu_suspicious+0xce/0xf0
[86220.126365]  ___might_sleep+0x1d3/0x240
[86220.126390]  __might_sleep+0x45/0x80
[86220.126416]  kmem_cache_alloc_trace+0x53/0x250
[86220.126458]  ? ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.126498]  ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.126538]  ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.126580]  ? ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.126623]  addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.126664]  ? addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.126708]  addrconf_verify_work+0xe/0x20 [ipv6]
[86220.126738]  process_one_work+0x258/0x680
[86220.126765]  worker_thread+0x35/0x3f0
[86220.126790]  kthread+0x124/0x140
[86220.126813]  ? process_one_work+0x680/0x680
[86220.126839]  ? kthread_create_worker_on_cpu+0x40/0x40
[86220.126869]  ? umh_complete+0x40/0x40
[86220.126893]  ? call_usermodehelper_exec_async+0x12a/0x160
[86220.126926]  ret_from_fork+0x4b/0x60
[86220.126999] BUG: sleeping function called from invalid context at mm/slab.h:420
[86220.127041] in_atomic(): 1, irqs_disabled(): 0, pid: 1003, name: kworker/0:2
[86220.127082] 4 locks held by kworker/0:2/1003:
[86220.127107]  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.127179]  #1:  ((addr_chk_work).work){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.127242]  #2:  (rtnl_mutex){+.+.}, at: [<00000000b06d9510>] rtnl_lock+0x12/0x20
[86220.127300]  #3:  (rcu_read_lock_bh){....}, at: [<00000000aef52299>] addrconf_verify_rtnl+0x1e/0x510 [ipv6]
[86220.127414] CPU: 0 PID: 1003 Comm: kworker/0:2 Not tainted 4.15.0-rc7-next-20180110+ #7
[86220.127463] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015
[86220.127528] Workqueue: ipv6_addrconf addrconf_verify_work [ipv6]
[86220.127568] Call Trace:
[86220.127591]  dump_stack+0x70/0x9e
[86220.127616]  ___might_sleep+0x14d/0x240
[86220.127644]  __might_sleep+0x45/0x80
[86220.127672]  kmem_cache_alloc_trace+0x53/0x250
[86220.127717]  ? ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.127762]  ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.127807]  ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.127854]  ? ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.127903]  addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.127950]  ? addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.127998]  addrconf_verify_work+0xe/0x20 [ipv6]
[86220.128032]  process_one_work+0x258/0x680
[86220.128063]  worker_thread+0x35/0x3f0
[86220.128091]  kthread+0x124/0x140
[86220.128117]  ? process_one_work+0x680/0x680
[86220.128146]  ? kthread_create_worker_on_cpu+0x40/0x40
[86220.128180]  ? umh_complete+0x40/0x40
[86220.128207]  ? call_usermodehelper_exec_async+0x12a/0x160
[86220.128243]  ret_from_fork+0x4b/0x60

Fixes: f3d9832e ("ipv6: addrconf: cleanup locking in ipv6_add_addr")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NHeiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In current route cache aging logic, if a route has both RTF_EXPIRE and
RTF_GATEWAY set, the route will only be removed if the neighbor cache
has no NTF_ROUTER flag. Otherwise, even if the route has expired, it
won't get deleted.
Fix this logic to always check if the route has expired first and then
do the gateway neighbor cache check if previous check decide to not
remove the exception entry.

Fixes: 1859bac0 ("ipv6: remove from fib tree aged out RTF_CACHE dst")
Signed-off-by: NWei Wang <weiwan@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Unsolicited IPv6 neighbor advertisements should be sent after DAD
completes. Update ndisc_send_unsol_na to skip tentative, non-optimistic
addresses and have those sent by addrconf_dad_completed after DAD.

Fixes: 4a6e3c5d ("net: ipv6: send unsolicited NA on admin up")
Reported-by: NVivek Venkatraman <vivek@cumulusnetworks.com>
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a sk_v6_rcv_saddr is !IPV6_ADDR_ANY and !IPV6_ADDR_MAPPED, it
implicitly implies it is an ipv6only socket.  However, in inet6_bind(),
this addr_type checking and setting sk->sk_ipv6only to 1 are only done
after sk->sk_prot->get_port(sk, snum) has been completed successfully.

This inconsistency between sk_v6_rcv_saddr and sk_ipv6only confuses
the 'get_port()'.

In particular, when binding SO_REUSEPORT UDP sockets,
udp_reuseport_add_sock(sk,...) is called.  udp_reuseport_add_sock()
checks "ipv6_only_sock(sk2) == ipv6_only_sock(sk)" before adding sk to
sk2->sk_reuseport_cb.  In this case, ipv6_only_sock(sk2) could be
1 while ipv6_only_sock(sk) is still 0 here.  The end result is,
reuseport_alloc(sk) is called instead of adding sk to the existing
sk2->sk_reuseport_cb.

It can be reproduced by binding two SO_REUSEPORT UDP sockets on an
IPv6 address (!ANY and !MAPPED).  Only one of the socket will
receive packet.

The fix is to set the implicit sk_ipv6only before calling get_port().
The original sk_ipv6only has to be saved such that it can be restored
in case get_port() failed.  The situation is similar to the
inet_reset_saddr(sk) after get_port() has failed.

Thanks to Calvin Owens <calvinowens@fb.com> who created an easy
reproduction which leads to a fix.

Fixes: e32ea7e7 ("soreuseport: fast reuseport UDP socket selection")
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to IPv4 allow routes to be added with the RTNH_F_ONLINK flag.
The onlink option requires a gateway and a nexthop device. Any unicast
gateway is allowed (including IPv4 mapped addresses and unresolved
ones) as long as the gateway is not a local address and if it resolves
it must match the given device.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

onlink verification needs to do a lookup in potentially different
table than the table in fib6_config and without the RT6_LOOKUP_F_IFACE
flag. Change ip6_nh_lookup_table to take table id and flags as input
arguments. Both verifications want to ignore link state, so add that
flag can stay in the lookup helper.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move existing code to validate nexthop into a helper. Follow on patch
adds support for nexthops marked with onlink, and this helper keeps
the complexity of ip6_route_info_create in check.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Originally the erspan fields are defined as a group into a __be16 field,
and use mask and offset to access each field.  This is more costly due to
calling ntohs/htons.  The patch changes it to use bitfields.
Signed-off-by: NWilliam Tu <u9012063@gmail.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some dst_ops (e.g. md_dst_ops)) doesn't set this handler. It may result to:
"BUG: unable to handle kernel NULL pointer dereference at           (null)"

Let's add a helper to check if update_pmtu is available before calling it.

Fixes: 52a589d5 ("geneve: update skb dst pmtu on tx path")
Fixes: a93bf0ff ("vxlan: update skb dst pmtu on tx path")
CC: Roman Kapl <code@rkapl.cz>
CC: Xin Long <lucien.xin@gmail.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPv6 allows routes to be installed when the device is not up (admin up).
Worse, it does not mark it as LINKDOWN. IPv4 does not allow it and really
there is no reason for IPv6 to allow it, so check the flags and deny if
device is admin down.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Reviewed-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 513674b5 ("net: reevalulate autoflowlabel setting after
sysctl setting") removed the initialisation of
ipv6_pinfo::autoflowlabel and added a second flag to indicate
whether this field or the net namespace default should be used.

The getsockopt() handling for this case was not updated, so it
currently returns 0 for all sockets for which IPV6_AUTOFLOWLABEL is
not explicitly enabled.  Fix it to return the effective value, whether
that has been set at the socket or net namespace level.

Fixes: 513674b5 ("net: reevalulate autoflowlabel setting after sysctl ...")
Signed-off-by: NBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>