It seems that kernel memory can leak into userspace by a
kmalloc, ethtool_get_strings, then copy_to_user sequence.

Avoid this by using kcalloc to zero fill the copied buffer.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 6e498158 ("tipc: move link synch and failover to link aggregation level")
we introduced a new mechanism for performing link failover and
synchronization. We have now detected a bug in this mechanism.

During link synchronization we use the arrival of any packet on
the tunnel link to trig a check for whether it has reached the
synchronization point or not. This has turned out to be too
permissive, since it may cause an arriving non-last SYNCH packet to
end the synch state, just to see the next SYNCH packet initiate a
new synch state with a new, higher synch point. This is not fatal,
but should be avoided, because it may significantly extend the
synchronization period, while at the same time we are not allowed
to send NACKs if packets are lost. In the worst case, a low-traffic
user may see its traffic stall until a LINK_PROTOCOL state message
trigs the link to leave synchronization state.

At the same time, LINK_PROTOCOL packets which happen to have a (non-
valid) sequence number lower than the tunnel link's rcv_nxt value will
be consistently dropped, and will never be able to resolve the situation
described above.

We fix this by exempting LINK_PROTOCOL packets from the sequence number
check, as they should be. We also reduce (but don't completely
eliminate) the risk of entering multiple synchronization states by only
allowing the (logically) first SYNCH packet to initiate a synchronization
state. This works independently of actual packet arrival order.

Fixes: commit 6e498158 ("tipc: move link synch and failover to link aggregation level")
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As originally written rt6_uncached_list_flush_dev makes no sense when
called with dev == NULL as it attempts to flush all uncached routes
regardless of network namespace when dev == NULL.  Which is simply
incorrect behavior.

Furthermore at the point rt6_ifdown is called with dev == NULL no more
network devices exist in the network namespace so even if the code in
rt6_uncached_list_flush_dev were to attempt something sensible it
would be meaningless.

Therefore remove support in rt6_uncached_list_flush_dev for handling
network devices where dev == NULL, and only call rt6_uncached_list_flush_dev
 when rt6_ifdown is called with a network device.

Fixes: 8d0b94af ("ipv6: Keep track of DST_NOCACHE routes in case of iface down/unregister")
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: NMartin KaFai Lau <kafai@fb.com>
Tested-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

VLANs 0 and 4095 are reserved and shouldn't be used, add checks to
switchdev similar to the bridge. Also make sure ids above 4095 cannot
be passed either.

Fixes: 47f8328b ("switchdev: add new switchdev bridge setlink")
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: NScott Feldman <sfeldma@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 30686bf7 ("mac80211: convert HW flags to unsigned long
bitmap") accidentally removed the newline delimiter from the hwflags
debugfs file. Fix this by adding back the newline between the HW flags.

Cc: stable@vger.kernel.org [4.2]
Signed-off-by: NMohammed Shafi Shajakhan <mohammed@qti.qualcomm.com>
[fix commit log]
Signed-off-by: NJouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This is a clone of commit 2ab95749 ("ip_forward: Drop frames with
attached skb->sk") for ipv6.

This commit has exactly the same reasons as the above mentioned commit,
namely to prevent panics during netfilter reload or a misconfigured stack.
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

GRE point-to-point interfaces should also support ipv6 multicast. Setting
up default multicast routes on interface creation was forgotten. Add it.

Bugzilla: <https://bugzilla.kernel.org/show_bug.cgi?id=103231>
Cc: Julien Muchembled <jm@jmuchemb.eu>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Nicolas Dumazet <ndumazet@google.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to commit c0afd9ce ("fq_codel: fix return value of fq_codel_drop()")
->drop() is supposed to return the number of bytes it dropped,
but hhf_drop () returns the id of the bucket where it drops
a packet from.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Terry Lam <vtlam@google.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to commit c29390c6 ("xps: must clear sender_cpu before forwarding")
the skb->sender_cpu needs to be cleared before xmit.

Fixes: 3896d655 ("bpf: introduce bpf_clone_redirect() helper")
Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to commit c29390c6 ("xps: must clear sender_cpu before forwarding")
the skb->sender_cpu needs to be cleared when moving from Rx
Tx, otherwise kernel could crash.

Fixes: 2bd82484 ("xps: fix xps for stacked devices")
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously, the CT_ATTR_FLAGS attribute, when nested under the
OVS_ACTION_ATTR_CT, encoded a 32-bit bitmask of flags that modify the
semantics of the ct action. It's more extensible to just represent each
flag as a nested attribute, and this requires no additional error
checking to reject flags that aren't currently supported.
Suggested-by: NBen Pfaff <blp@nicira.com>
Signed-off-by: NJoe Stringer <joestringer@nicira.com>
Acked-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ct_state field was initially added as an 8-bit field, however six of
the bits are already being used and use cases are already starting to
appear that may push the limits of this field. This patch extends the
field to 32 bits while retaining the internal representation of 8 bits.
This should cover forward compatibility of the ABI for the foreseeable
future.

This patch also reorders the OVS_CS_F_* bits to be sequential.
Suggested-by: NJarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: NJoe Stringer <joestringer@nicira.com>
Acked-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously, if userspace specified ct_state bits in the flow key which
are currently undefined (and therefore unsupported), then they would be
ignored. This could cause unexpected behaviour in future if userspace is
extended to support additional bits but attempts to communicate with the
current version of the kernel. This patch rectifies the situation by
rejecting such ct_state bits.

Fixes: 7f8a436e "openvswitch: Add conntrack action"
Signed-off-by: NJoe Stringer <joestringer@nicira.com>
Acked-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ct action uses parts of the flow key, so we need to ensure that it
is valid before executing that action.

Fixes: 7f8a436e "openvswitch: Add conntrack action"
Signed-off-by: NJoe Stringer <joestringer@nicira.com>
Acked-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If ovs_fragment() was unable to fragment the skb due to an L2 header
that exceeds the supported length, skbs would be leaked. Fix the bug.

Fixes: 7f8a436e "openvswitch: Add conntrack action"
Signed-off-by: NJoe Stringer <joestringer@nicira.com>
Acked-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If no switch were found in dsa_setup_dst, return -ENODEV and
exit the dsa_probe cleanly.
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now the kfree calls exists in the the remove functions, remove them in all
places except the of_probe functions and replace allocation calls
with their devm_ counterparts.
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When unbinding dsa, complete the dsa_switch_destroy to unregister the
fixed link phy then cleanly unregister and destroy the net devices.
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To prevent memory leakage on unbinding, add missing mdiobus unregister
and unallocation calls.
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To prevent memory leakage on unbinding, add missing kfree calls.
Includes minor cosmetic change to make patch clean.
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It occurred to me yesterday that 741a11d9 ("net: ipv6: Add
RT6_LOOKUP_F_IFACE flag if oif is set") means that xfrm6_dst_lookup
needs the FLOWI_FLAG_SKIP_NH_OIF flag set. This latest commit causes
the oif to be considered in lookups which is known to break vti. This
explains why 58189ca7 did not the IPv6 change at the time it was
submitted.

Fixes: 42a7b32b ("xfrm: Add oif to dst lookups")
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Not every device has dev->tstats set. So when OVS tries to calculate
vport stats it causes kernel panic. Following patch fixes it by
using standard API to get net-device stats.

---8<---
Unable to handle kernel paging request at virtual address 766b4008
Internal error: Oops: 96000005 [#1] PREEMPT SMP
Modules linked in: vport_vxlan vxlan ip6_udp_tunnel udp_tunnel tun bridge stp llc openvswitch ipv6
CPU: 7 PID: 1108 Comm: ovs-vswitchd Not tainted 4.3.0-rc3+ #82
PC is at ovs_vport_get_stats+0x150/0x1f8 [openvswitch]
<snip>
Call trace:
 [<ffffffbffc0859f8>] ovs_vport_get_stats+0x150/0x1f8 [openvswitch]
 [<ffffffbffc07cdb0>] ovs_vport_cmd_fill_info+0x140/0x1e0 [openvswitch]
 [<ffffffbffc07cf0c>] ovs_vport_cmd_dump+0xbc/0x138 [openvswitch]
 [<ffffffc00045a5ac>] netlink_dump+0xb8/0x258
 [<ffffffc00045ace0>] __netlink_dump_start+0x120/0x178
 [<ffffffc00045dd9c>] genl_family_rcv_msg+0x2d4/0x308
 [<ffffffc00045de58>] genl_rcv_msg+0x88/0xc4
 [<ffffffc00045cf24>] netlink_rcv_skb+0xd4/0x100
 [<ffffffc00045dab0>] genl_rcv+0x30/0x48
 [<ffffffc00045c830>] netlink_unicast+0x154/0x200
 [<ffffffc00045cc9c>] netlink_sendmsg+0x308/0x364
 [<ffffffc00041e10c>] sock_sendmsg+0x14/0x2c
 [<ffffffc000420d58>] SyS_sendto+0xbc/0xf0
Code: aa1603e1 f94037a4 aa1303e2 aa1703e0 (f9400465)
Reported-by: NTomasz Sawicki <tomasz.sawicki@objectiveintegration.uk>
Fixes: 8c876639 ("openvswitch: Remove vport stats.")
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When openvswitch tries allocate memory from offline numa node 0:
stats = kmem_cache_alloc_node(flow_stats_cache, GFP_KERNEL | __GFP_ZERO, 0)
It catches VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES || !node_online(nid))
[ replaced with VM_WARN_ON(!node_online(nid)) recently ] in linux/gfp.h
This patch disables numa affinity in this case.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When sockets have a native eBPF program attached through
setsockopt(sk, SOL_SOCKET, SO_ATTACH_BPF, ...), and then try to
dump these over getsockopt(sk, SOL_SOCKET, SO_GET_FILTER, ...),
the following panic appears:

  [49904.178642] BUG: unable to handle kernel NULL pointer dereference at (null)
  [49904.178762] IP: [<ffffffff81610fd9>] sk_get_filter+0x39/0x90
  [49904.182000] PGD 86fc9067 PUD 531a1067 PMD 0
  [49904.185196] Oops: 0000 [#1] SMP
  [...]
  [49904.224677] Call Trace:
  [49904.226090]  [<ffffffff815e3d49>] sock_getsockopt+0x319/0x740
  [49904.227535]  [<ffffffff812f59e3>] ? sock_has_perm+0x63/0x70
  [49904.228953]  [<ffffffff815e2fc8>] ? release_sock+0x108/0x150
  [49904.230380]  [<ffffffff812f5a43>] ? selinux_socket_getsockopt+0x23/0x30
  [49904.231788]  [<ffffffff815dff36>] SyS_getsockopt+0xa6/0xc0
  [49904.233267]  [<ffffffff8171b9ae>] entry_SYSCALL_64_fastpath+0x12/0x71

The underlying issue is the very same as in commit b382c086
("sock, diag: fix panic in sock_diag_put_filterinfo"), that is,
native eBPF programs don't store an original program since this
is only needed in cBPF ones.

However, sk_get_filter() wasn't updated to test for this at the
time when eBPF could be attached. Just throw an error to the user
to indicate that eBPF cannot be dumped over this interface.
That way, it can also be known that a program _is_ attached (as
opposed to just return 0), and a different (future) method needs
to be consulted for a dump.

Fixes: 89aa0758 ("net: sock: allow eBPF programs to be attached to sockets")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Conntrack LABELS (plural) are exposed by conntrack; rename the OVS name
for these to be consistent with conntrack.

Fixes: c2ac6673 "openvswitch: Allow matching on conntrack label"
Signed-off-by: NJoe Stringer <joestringer@nicira.com>
Acked-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now send with MSG_PEEK can return data from multiple SKBs.

Unfortunately we take into account the peek offset for each skb,
that is wrong. We need to apply the peek offset only once.

In addition, the peek offset should be used only if MSG_PEEK is set.

Cc: "David S. Miller" <davem@davemloft.net> (maintainer:NETWORKING
Cc: Eric Dumazet <edumazet@google.com> (commit_signer:1/14=7%)
Cc: Aaron Conole <aconole@bytheb.org>
Fixes: 9f389e35 ("af_unix: return data from multiple SKBs on recv() with MSG_PEEK flag")
Signed-off-by: NAndrey Vagin <avagin@openvz.org>
Tested-by: NAaron Conole <aconole@bytheb.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Align with other tc actions.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After commit 1ce87720 ("net: sched: make cls_u32 lockless")
we began to release tc actions in a RCU callback. However,
mirred action relies on RTNL lock to protect the global
mirred_list, therefore we could have a race condition
between RCU callback and netdevice event, which caused
a list corruption as reported by Vinson.

Instead of relying on RTNL lock, introduce a spinlock to
protect this list.

Note, in non-bind case, it is still called with RTNL lock,
therefore should disable BH too.
Reported-by: NVinson Lee <vlee@twopensource.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are cases when the created metadata reply is not used. Ensure the
allocated memory is freed also in such cases.

Fixes: 63d008a4 ("ipv4: send arp replies to the correct tunnel")
Reported-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

reqsk_timer_handler() tests if icsk_accept_queue.listen_opt
is NULL at its beginning.

By the time it calls inet_csk_reqsk_queue_drop() and
reqsk_queue_unlink(), listener might have been closed and
inet_csk_listen_stop() had called reqsk_queue_yank_acceptq()
which sets icsk_accept_queue.listen_opt to NULL

We therefore need to correctly check listen_opt being NULL
after holding syn_wait_lock for proper synchronization.

Fixes: fa76ce73 ("inet: get rid of central tcp/dccp listener timer")
Fixes: b357a364 ("inet: fix possible panic in reqsk_queue_unlink()")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The fib_table_lookup tracepoint found 2 places where the flowi4_flags is
not initialized.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Because of the default 0 value of ret in dsa_slave_port_attr_set, a
driver may return -EOPNOTSUPP from the commit phase of a STP state,
which triggers a WARN() from switchdev.

This happened on a 6185 switch which does not support hardware bridging.

Fixes: 35636062 ("switchdev: convert STP update to switchdev attr set")
Reported-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Earlier patch 6ae459bd tried to detect void ckecksum partial
skb by comparing pull length to checksum offset. But it does
not work for all cases since checksum-offset depends on
updates to skb->data.

Following patch fixes it by validating checksum start offset
after skb-data pointer is updated. Negative value of checksum
offset start means there is no need to checksum.

Fixes: 6ae459bd ("skbuff: Fix skb checksum flag on skb pull")
Reported-by: NAndrew Vagin <avagin@odin.com>
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Wolfgang reported that IPv6 stack is ignoring oif in output route lookups:

    With ipv6, ip -6 route get always returns the specific route.

    $ ip -6 r
    2001:db8:e2::1 dev enp2s0  proto kernel  metric 256
    2001:db8:e2::/64 dev enp2s0  metric 1024
    2001:db8:e3::1 dev enp3s0  proto kernel  metric 256
    2001:db8:e3::/64 dev enp3s0  metric 1024
    fe80::/64 dev enp3s0  proto kernel  metric 256
    default via 2001:db8:e3::255 dev enp3s0  metric 1024

    $ ip -6 r get 2001:db8:e2::100
    2001:db8:e2::100 from :: dev enp2s0  src 2001:db8:e3::1  metric 0
        cache

    $ ip -6 r get 2001:db8:e2::100 oif enp3s0
    2001:db8:e2::100 from :: dev enp2s0  src 2001:db8:e3::1  metric 0
        cache

The stack does consider the oif but a mismatch in rt6_device_match is not
considered fatal because RT6_LOOKUP_F_IFACE is not set in the flags.

Cc: Wolfgang Nothdurft <netdev@linux-dude.de>
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Otherwise 4294967295 (MBit/s) (-1) will be printed when there is no link.
Documentation/ABI/testing/sysfs-class-net does not state if this shall be
signed or unsigned.
Also remove the now unused variable fmt_udec.
Signed-off-by: NAlexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

AF_UNIX sockets now return multiple skbs from recv() when MSG_PEEK flag
is set.

This is referenced in kernel bugzilla #12323 @
https://bugzilla.kernel.org/show_bug.cgi?id=12323

As described both in the BZ and lkml thread @
http://lkml.org/lkml/2008/1/8/444 calling recv() with MSG_PEEK on an
AF_UNIX socket only reads a single skb, where the desired effect is
to return as much skb data has been queued, until hitting the recv
buffer size (whichever comes first).

The modified MSG_PEEK path will now move to the next skb in the tree
and jump to the again: label, rather than following the natural loop
structure. This requires duplicating some of the loop head actions.

This was tested using the python socketpair python code attached to
the bugzilla issue.
Signed-off-by: NAaron Conole <aconole@bytheb.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Seemingly innocuous sctp_trans_state_to_prio_map[] array
is way bigger than it looks, since
"[SCTP_UNKNOWN] = 2" expands into "[0xffff] = 2" !

This patch replaces it with switch() statement.
Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: Neil Horman <nhorman@tuxdriver.com>
CC: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
CC: linux-sctp@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-kernel@vger.kernel.org
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is a small chance that tunnel_free() is called before tunnel->del_work scheduled
resulting in a zero pointer dereference.
Signed-off-by: NAlexander Couzens <lynxis@fe80.eu>
Acked-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A case can occur when sctp_accept() is called by the user during
a heartbeat timeout event after the 4-way handshake.  Since
sctp_assoc_migrate() changes both assoc->base.sk and assoc->ep, the
bh_sock_lock in sctp_generate_heartbeat_event() will be taken with
the listening socket but released with the new association socket.
The result is a deadlock on any future attempts to take the listening
socket lock.

Note that this race can occur with other SCTP timeouts that take
the bh_lock_sock() in the event sctp_accept() is called.

 BUG: soft lockup - CPU#9 stuck for 67s! [swapper:0]
 ...
 RIP: 0010:[<ffffffff8152d48e>]  [<ffffffff8152d48e>] _spin_lock+0x1e/0x30
 RSP: 0018:ffff880028323b20  EFLAGS: 00000206
 RAX: 0000000000000002 RBX: ffff880028323b20 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff880028323be0 RDI: ffff8804632c4b48
 RBP: ffffffff8100bb93 R08: 0000000000000000 R09: 0000000000000000
 R10: ffff880610662280 R11: 0000000000000100 R12: ffff880028323aa0
 R13: ffff8804383c3880 R14: ffff880028323a90 R15: ffffffff81534225
 FS:  0000000000000000(0000) GS:ffff880028320000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
 CR2: 00000000006df528 CR3: 0000000001a85000 CR4: 00000000000006e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process swapper (pid: 0, threadinfo ffff880616b70000, task ffff880616b6cab0)
 Stack:
 ffff880028323c40 ffffffffa01c2582 ffff880614cfb020 0000000000000000
 <d> 0100000000000000 00000014383a6c44 ffff8804383c3880 ffff880614e93c00
 <d> ffff880614e93c00 0000000000000000 ffff8804632c4b00 ffff8804383c38b8
 Call Trace:
 <IRQ>
 [<ffffffffa01c2582>] ? sctp_rcv+0x492/0xa10 [sctp]
 [<ffffffff8148c559>] ? nf_iterate+0x69/0xb0
 [<ffffffff814974a0>] ? ip_local_deliver_finish+0x0/0x2d0
 [<ffffffff8148c716>] ? nf_hook_slow+0x76/0x120
 [<ffffffff814974a0>] ? ip_local_deliver_finish+0x0/0x2d0
 [<ffffffff8149757d>] ? ip_local_deliver_finish+0xdd/0x2d0
 [<ffffffff81497808>] ? ip_local_deliver+0x98/0xa0
 [<ffffffff81496ccd>] ? ip_rcv_finish+0x12d/0x440
 [<ffffffff81497255>] ? ip_rcv+0x275/0x350
 [<ffffffff8145cfeb>] ? __netif_receive_skb+0x4ab/0x750
 ...

With lockdep debugging:

 =====================================
 [ BUG: bad unlock balance detected! ]
 -------------------------------------
 CslRx/12087 is trying to release lock (slock-AF_INET) at:
 [<ffffffffa01bcae0>] sctp_generate_timeout_event+0x40/0xe0 [sctp]
 but there are no more locks to release!

 other info that might help us debug this:
 2 locks held by CslRx/12087:
 #0:  (&asoc->timers[i]){+.-...}, at: [<ffffffff8108ce1f>] run_timer_softirq+0x16f/0x3e0
 #1:  (slock-AF_INET){+.-...}, at: [<ffffffffa01bcac3>] sctp_generate_timeout_event+0x23/0xe0 [sctp]

Ensure the socket taken is also the same one that is released by
saving a copy of the socket before entering the timeout event
critical section.
Signed-off-by: NKarl Heiss <kheiss@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix indentation in sctp_generate_heartbeat_event.
Signed-off-by: NKarl Heiss <kheiss@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>