The last argument to __skb_header_pointer() should be a buffer large
enough to store struct arphdr. This can be a pointer to a struct arphdr
structure. The code was previously using a pointer to a pointer to
struct arphdr.

By my counting the storage available both before and after is 8 bytes on
x86_64.

Fixes: 55733350 ("flow disector: ARP support")
Reported-by: NNicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Callers of l2tp_nl_session_find() need to hold a reference on the
returned session since there's no guarantee that it isn't going to
disappear from under them.

Relying on the fact that no l2tp netlink message may be processed
concurrently isn't enough: sessions can be deleted by other means
(e.g. by closing the PPPOL2TP socket of a ppp pseudowire).

l2tp_nl_cmd_session_delete() is a bit special: it runs a callback
function that may require a previous call to session->ref(). In
particular, for ppp pseudowires, the callback is l2tp_session_delete(),
which then calls pppol2tp_session_close() and dereferences the PPPOL2TP
socket. The socket might already be gone at the moment
l2tp_session_delete() calls session->ref(), so we need to take a
reference during the session lookup. So we need to pass the do_ref
variable down to l2tp_session_get() and l2tp_session_get_by_ifname().

Since all callers have to be updated, l2tp_session_find_by_ifname() and
l2tp_nl_session_find() are renamed to reflect their new behaviour.

Fixes: 309795f4 ("l2tp: Add netlink control API for L2TP")
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

l2tp_session_find() doesn't take any reference on the returned session.
Therefore, the session may disappear while sending the notification.

Use l2tp_session_get() instead and decrement session's refcount once
the notification is sent.

Fixes: 33f72e6f ("l2tp : multicast notification to the registered listeners")
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

l2tp_session_create() relies on its caller for checking for duplicate
sessions. This is racy since a session can be concurrently inserted
after the caller's verification.

Fix this by letting l2tp_session_create() verify sessions uniqueness
upon insertion. Callers need to be adapted to check for
l2tp_session_create()'s return code instead of calling
l2tp_session_find().

pppol2tp_connect() is a bit special because it has to work on existing
sessions (if they're not connected) or to create a new session if none
is found. When acting on a preexisting session, a reference must be
held or it could go away on us. So we have to use l2tp_session_get()
instead of l2tp_session_find() and drop the reference before exiting.

Fixes: d9e31d17 ("l2tp: Add L2TP ethernet pseudowire support")
Fixes: fd558d18 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Holding a reference on session is required before calling
pppol2tp_session_ioctl(). The session could get freed while processing the
ioctl otherwise. Since pppol2tp_session_ioctl() uses the session's socket,
we also need to take a reference on it in l2tp_session_get().

Fixes: fd558d18 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Taking a reference on sessions in l2tp_recv_common() is racy; this
has to be done by the callers.

To this end, a new function is required (l2tp_session_get()) to
atomically lookup a session and take a reference on it. Callers then
have to manually drop this reference.

Fixes: fd558d18 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since sctp reconf was added in sctp, the real cnt of in/out stream
have not been c.sinit_max_instreams and c.sinit_num_ostreams any
more.

This patch is to replace them with stream->in/outcnt.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ovs_flow_key_update() is called when the flow key is invalid, and it is
used to update and revalidate the flow key. Commit 329f45bc
("openvswitch: add mac_proto field to the flow key") introduces mac_proto
field to flow key and use it to determine whether the flow key is valid.
However, the commit does not update the code path in ovs_flow_key_update()
to revalidate the flow key which may cause BUG_ON() on execute_recirc().
This patch addresses the aforementioned issue.

Fixes: 329f45bc ("openvswitch: add mac_proto field to the flow key")
Signed-off-by: NYi-Hung Wei <yihung.wei@gmail.com>
Acked-by: NJiri Benc <jbenc@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When sending a msg without asoc established, sctp will send INIT packet
first and then enqueue chunks.

Before receiving INIT_ACK, stream info is not yet alloced. But enqueuing
chunks needs to access stream info, like out stream state and out stream
cnt.

This patch is to fix it by allocing out stream info when initializing an
asoc, allocing in stream and re-allocing out stream when processing init.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When calculating po->tp_hdrlen + po->tp_reserve the result can overflow.

Fix by checking that tp_reserve <= INT_MAX on assign.
Signed-off-by: NAndrey Konovalov <andreyknvl@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When calculating rb->frames_per_block * req->tp_block_nr the result
can overflow.

Add a check that tp_block_size * tp_block_nr <= UINT_MAX.

Since frames_per_block <= tp_block_size, the expression would
never overflow.
Signed-off-by: NAndrey Konovalov <andreyknvl@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Subtracting tp_sizeof_priv from tp_block_size and casting to int
to check whether one is less then the other doesn't always work
(both of them are unsigned ints).

Compare them as is instead.

Also cast tp_sizeof_priv to u64 before using BLK_PLUS_PRIV, as
it can overflow inside BLK_PLUS_PRIV otherwise.
Signed-off-by: NAndrey Konovalov <andreyknvl@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The Rx path may grab the socket right before pppol2tp_release(), but
nothing guarantees that it will enqueue packets before
skb_queue_purge(). Therefore, the socket can be destroyed without its
queues fully purged.

Fix this by purging queues in pppol2tp_session_destruct() where we're
guaranteed nothing is still referencing the socket.

Fixes: 9e9cb622 ("l2tp: fix userspace reception on plain L2TP sockets")
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The code following l2tp_tunnel_find() expects that a new reference is
held on sk. Either sk_receive_skb() or the discard_put error path will
drop a reference from the tunnel's socket.

This issue exists in both l2tp_ip and l2tp_ip6.

Fixes: a3c18422 ("l2tp: hold socket before dropping lock in l2tp_ip{, 6}_recv()")
Signed-off-by: NGuillaume Nault <g.nault@alphalink.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When internal mac80211 TXQs aren't supported, netdev queues must
always started out started even when driver queues are stopped
while the interface is added. This is necessary because with the
internal TXQ support netdev queues are never stopped and packet
scheduling/dropping is done in mac80211.

Cc: stable@vger.kernel.org # 4.9+
Fixes: 80a83cfc ("mac80211: skip netdev queue control with software queuing")
Reported-and-tested-by: NSven Eckelmann <sven.eckelmann@openmesh.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

We must call security_release_secctx to free the memory returned by
security_secid_to_secctx, otherwise memory may be leaked forever.

Fixes: ef493bd9 ("netfilter: nfnetlink_queue: add security context information")
Signed-off-by: NLiping Zhang <zlpnobody@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

We got the following use-after-free KASAN report:

 BUG: KASAN: use-after-free in wiphy_resume+0x591/0x5a0 [cfg80211]
	 at addr ffff8803fc244090
 Read of size 8 by task kworker/u16:24/2587
 CPU: 6 PID: 2587 Comm: kworker/u16:24 Tainted: G    B 4.9.13-debug+
 Hardware name: Dell Inc. XPS 15 9550/0N7TVV, BIOS 1.2.19 12/22/2016
 Workqueue: events_unbound async_run_entry_fn
  ffff880425d4f9d8 ffffffffaeedb541 ffff88042b80ef00 ffff8803fc244088
  ffff880425d4fa00 ffffffffae84d7a1 ffff880425d4fa98 ffff8803fc244080
  ffff88042b80ef00 ffff880425d4fa88 ffffffffae84da3a ffffffffc141f7d9
 Call Trace:
  [<ffffffffaeedb541>] dump_stack+0x85/0xc4
  [<ffffffffae84d7a1>] kasan_object_err+0x21/0x70
  [<ffffffffae84da3a>] kasan_report_error+0x1fa/0x500
  [<ffffffffc141f7d9>] ? cfg80211_bss_age+0x39/0xc0 [cfg80211]
  [<ffffffffc141f83a>] ? cfg80211_bss_age+0x9a/0xc0 [cfg80211]
  [<ffffffffae48d46d>] ? trace_hardirqs_on+0xd/0x10
  [<ffffffffc13fb1c0>] ? wiphy_suspend+0xc70/0xc70 [cfg80211]
  [<ffffffffae84def1>] __asan_report_load8_noabort+0x61/0x70
  [<ffffffffc13fb100>] ? wiphy_suspend+0xbb0/0xc70 [cfg80211]
  [<ffffffffc13fb751>] ? wiphy_resume+0x591/0x5a0 [cfg80211]
  [<ffffffffc13fb751>] wiphy_resume+0x591/0x5a0 [cfg80211]
  [<ffffffffc13fb1c0>] ? wiphy_suspend+0xc70/0xc70 [cfg80211]
  [<ffffffffaf3b206e>] dpm_run_callback+0x6e/0x4f0
  [<ffffffffaf3b31b2>] device_resume+0x1c2/0x670
  [<ffffffffaf3b367d>] async_resume+0x1d/0x50
  [<ffffffffae3ee84e>] async_run_entry_fn+0xfe/0x610
  [<ffffffffae3d0666>] process_one_work+0x716/0x1a50
  [<ffffffffae3d05c9>] ? process_one_work+0x679/0x1a50
  [<ffffffffafdd7b6d>] ? _raw_spin_unlock_irq+0x3d/0x60
  [<ffffffffae3cff50>] ? pwq_dec_nr_in_flight+0x2b0/0x2b0
  [<ffffffffae3d1a80>] worker_thread+0xe0/0x1460
  [<ffffffffae3d19a0>] ? process_one_work+0x1a50/0x1a50
  [<ffffffffae3e54c2>] kthread+0x222/0x2e0
  [<ffffffffae3e52a0>] ? kthread_park+0x80/0x80
  [<ffffffffae3e52a0>] ? kthread_park+0x80/0x80
  [<ffffffffae3e52a0>] ? kthread_park+0x80/0x80
  [<ffffffffafdd86aa>] ret_from_fork+0x2a/0x40
 Object at ffff8803fc244088, in cache kmalloc-1024 size: 1024
 Allocated:
 PID = 71
  save_stack_trace+0x1b/0x20
  save_stack+0x46/0xd0
  kasan_kmalloc+0xad/0xe0
  kasan_slab_alloc+0x12/0x20
  __kmalloc_track_caller+0x134/0x360
  kmemdup+0x20/0x50
  brcmf_cfg80211_attach+0x10b/0x3a90 [brcmfmac]
  brcmf_bus_start+0x19a/0x9a0 [brcmfmac]
  brcmf_pcie_setup+0x1f1a/0x3680 [brcmfmac]
  brcmf_fw_request_nvram_done+0x44c/0x11b0 [brcmfmac]
  request_firmware_work_func+0x135/0x280
  process_one_work+0x716/0x1a50
  worker_thread+0xe0/0x1460
  kthread+0x222/0x2e0
  ret_from_fork+0x2a/0x40
 Freed:
 PID = 2568
  save_stack_trace+0x1b/0x20
  save_stack+0x46/0xd0
  kasan_slab_free+0x71/0xb0
  kfree+0xe8/0x2e0
  brcmf_cfg80211_detach+0x62/0xf0 [brcmfmac]
  brcmf_detach+0x14a/0x2b0 [brcmfmac]
  brcmf_pcie_remove+0x140/0x5d0 [brcmfmac]
  brcmf_pcie_pm_leave_D3+0x198/0x2e0 [brcmfmac]
  pci_pm_resume+0x186/0x220
  dpm_run_callback+0x6e/0x4f0
  device_resume+0x1c2/0x670
  async_resume+0x1d/0x50
  async_run_entry_fn+0xfe/0x610
  process_one_work+0x716/0x1a50
  worker_thread+0xe0/0x1460
  kthread+0x222/0x2e0
  ret_from_fork+0x2a/0x40
 Memory state around the buggy address:
  ffff8803fc243f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff8803fc244000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 >ffff8803fc244080: fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                          ^
  ffff8803fc244100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8803fc244180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

What is happening is that brcmf_pcie_resume() detects a device that
is no longer responsive and it decides to unbind resulting in a
wiphy_unregister() and wiphy_free() call. Now the wiphy instance
remains allocated, because PM needs to call wiphy_resume() for it.
However, brcmfmac already does a kfree() for the struct
cfg80211_registered_device::ops field. Change the checks in
wiphy_resume() to only access the struct cfg80211_registered_device::ops
if the wiphy instance is still registered at this time.

Cc: stable@vger.kernel.org # 4.10.x, 4.9.x
Reported-by: NDaniel J Blueman <daniel@quora.org>
Reviewed-by: NHante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: NPieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: NFranky Lin <franky.lin@broadcom.com>
Signed-off-by: NArend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The reference count held for skb needs to be released when the skb's
nfct pointer is cleared regardless of if nf_ct_delete() is called or
not.

Failing to release the skb's reference cound led to deferred conntrack
cleanup spinning forever within nf_conntrack_cleanup_net_list() when
cleaning up a network namespace:

   kworker/u16:0-19025 [004] 45981067.173642: sched_switch: kworker/u16:0:19025 [120] R ==> rcu_preempt:7 [120]
   kworker/u16:0-19025 [004] 45981067.173651: kernel_stack: <stack trace>
=> ___preempt_schedule (ffffffffa001ed36)
=> _raw_spin_unlock_bh (ffffffffa0713290)
=> nf_ct_iterate_cleanup (ffffffffc00a4454)
=> nf_conntrack_cleanup_net_list (ffffffffc00a5e1e)
=> nf_conntrack_pernet_exit (ffffffffc00a63dd)
=> ops_exit_list.isra.1 (ffffffffa06075f3)
=> cleanup_net (ffffffffa0607df0)
=> process_one_work (ffffffffa0084c31)
=> worker_thread (ffffffffa008592b)
=> kthread (ffffffffa008bee2)
=> ret_from_fork (ffffffffa071b67c)

Fixes: dd41d33f ("openvswitch: Add force commit.")
Reported-by: NYang Song <yangsong@vmware.com>
Signed-off-by: NJarno Rajahalme <jarno@ovn.org>
Acked-by: NJoe Stringer <joe@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

David Laight noticed the support for MSG_MORE with datamsg->force_delay
didn't really work as we expected, as the first msg with MSG_MORE set
would always block the following chunks' dequeuing.

This Patch is to rewrite it by saving the MSG_MORE flag into assoc as
David Laight suggested.

asoc->force_delay is used to save MSG_MORE flag before a msg is sent.
All chunks in queue would not be sent out if asoc->force_delay is set
by the msg with MSG_MORE flag, until a new msg without MSG_MORE flag
clears asoc->force_delay.

Note that this change would not affect the flush is generated by other
triggers, like asoc->state != ESTABLISHED, queue size > pmtu etc.

v1->v2:
  Not clear asoc->force_delay after sending the msg with MSG_MORE flag.

Fixes: 4ea0c32f ("sctp: add support for MSG_MORE")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NDavid Laight <david.laight@aculab.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Our chosen ic_dev may be anywhere in our list of ic_devs, and we may
free it before attempting to close others. When we compare d->dev and
ic_dev->dev, we're potentially dereferencing memory returned to the
allocator. This causes KASAN to scream for each subsequent ic_dev we
check.

As there's a 1-1 mapping between ic_devs and netdevs, we can instead
compare d and ic_dev directly, which implicitly handles the !ic_dev
case, and avoids the use-after-free. The ic_dev pointer may be stale,
but we will not dereference it.

Original splat:

[    6.487446] ==================================================================
[    6.494693] BUG: KASAN: use-after-free in ic_close_devs+0xc4/0x154 at addr ffff800367efa708
[    6.503013] Read of size 8 by task swapper/0/1
[    6.507452] CPU: 5 PID: 1 Comm: swapper/0 Not tainted 4.11.0-rc3-00002-gda42158 #8
[    6.514993] Hardware name: AppliedMicro Mustang/Mustang, BIOS 3.05.05-beta_rc Jan 27 2016
[    6.523138] Call trace:
[    6.525590] [<ffff200008094778>] dump_backtrace+0x0/0x570
[    6.530976] [<ffff200008094d08>] show_stack+0x20/0x30
[    6.536017] [<ffff200008bee928>] dump_stack+0x120/0x188
[    6.541231] [<ffff20000856d5e4>] kasan_object_err+0x24/0xa0
[    6.546790] [<ffff20000856d924>] kasan_report_error+0x244/0x738
[    6.552695] [<ffff20000856dfec>] __asan_report_load8_noabort+0x54/0x80
[    6.559204] [<ffff20000aae86ac>] ic_close_devs+0xc4/0x154
[    6.564590] [<ffff20000aaedbac>] ip_auto_config+0x2ed4/0x2f1c
[    6.570321] [<ffff200008084b04>] do_one_initcall+0xcc/0x370
[    6.575882] [<ffff20000aa31de8>] kernel_init_freeable+0x5f8/0x6c4
[    6.581959] [<ffff20000a16df00>] kernel_init+0x18/0x190
[    6.587171] [<ffff200008084710>] ret_from_fork+0x10/0x40
[    6.592468] Object at ffff800367efa700, in cache kmalloc-128 size: 128
[    6.598969] Allocated:
[    6.601324] PID = 1
[    6.603427]  save_stack_trace_tsk+0x0/0x418
[    6.607603]  save_stack_trace+0x20/0x30
[    6.611430]  kasan_kmalloc+0xd8/0x188
[    6.615087]  ip_auto_config+0x8c4/0x2f1c
[    6.619002]  do_one_initcall+0xcc/0x370
[    6.622832]  kernel_init_freeable+0x5f8/0x6c4
[    6.627178]  kernel_init+0x18/0x190
[    6.630660]  ret_from_fork+0x10/0x40
[    6.634223] Freed:
[    6.636233] PID = 1
[    6.638334]  save_stack_trace_tsk+0x0/0x418
[    6.642510]  save_stack_trace+0x20/0x30
[    6.646337]  kasan_slab_free+0x88/0x178
[    6.650167]  kfree+0xb8/0x478
[    6.653131]  ic_close_devs+0x130/0x154
[    6.656875]  ip_auto_config+0x2ed4/0x2f1c
[    6.660875]  do_one_initcall+0xcc/0x370
[    6.664705]  kernel_init_freeable+0x5f8/0x6c4
[    6.669051]  kernel_init+0x18/0x190
[    6.672534]  ret_from_fork+0x10/0x40
[    6.676098] Memory state around the buggy address:
[    6.680880]  ffff800367efa600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[    6.688078]  ffff800367efa680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[    6.695276] >ffff800367efa700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[    6.702469]                       ^
[    6.705952]  ffff800367efa780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[    6.713149]  ffff800367efa800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[    6.720343] ==================================================================
[    6.727536] Disabling lock debugging due to kernel taint
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: David S. Miller <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: James Morris <jmorris@namei.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: netdev@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the commit 93557f53 ("netfilter: nf_conntrack: nf_conntrack snmp
helper"), the snmp_helper is replaced by nf_nat_snmp_hook. So the
snmp_helper is never registered. But it still tries to unregister the
snmp_helper, it could cause the panic.

Now remove the useless snmp_helper and the unregister call in the
error handler.

Fixes: 93557f53 ("netfilter: nf_conntrack: nf_conntrack snmp helper")
Signed-off-by: NGao Feng <fgao@ikuai8.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

If one cpu is doing nf_ct_extend_unregister while another cpu is doing
__nf_ct_ext_add_length, then we may hit BUG_ON(t == NULL). Moreover,
there's no synchronize_rcu invocation after set nf_ct_ext_types[id] to
NULL, so it's possible that we may access invalid pointer.

But actually, most of the ct extends are built-in, so the problem listed
above will not happen. However, there are two exceptions: NF_CT_EXT_NAT
and NF_CT_EXT_SYNPROXY.

For _EXT_NAT, the panic will not happen, since adding the nat extend and
unregistering the nat extend are located in the same file(nf_nat_core.c),
this means that after the nat module is removed, we cannot add the nat
extend too.

For _EXT_SYNPROXY, synproxy extend may be added by init_conntrack, while
synproxy extend unregister will be done by synproxy_core_exit. So after
nf_synproxy_core.ko is removed, we may still try to add the synproxy
extend, then kernel panic may happen.

I know it's very hard to reproduce this issue, but I can play a tricky
game to make it happen very easily :)

Step 1. Enable SYNPROXY for tcp dport 1234 at FORWARD hook:
  # iptables -I FORWARD -p tcp --dport 1234 -j SYNPROXY
Step 2. Queue the syn packet to the userspace at raw table OUTPUT hook.
        Also note, in the userspace we only add a 20s' delay, then
        reinject the syn packet to the kernel:
  # iptables -t raw -I OUTPUT -p tcp --syn -j NFQUEUE --queue-num 1
Step 3. Using "nc 2.2.2.2 1234" to connect the server.
Step 4. Now remove the nf_synproxy_core.ko quickly:
  # iptables -F FORWARD
  # rmmod ipt_SYNPROXY
  # rmmod nf_synproxy_core
Step 5. After 20s' delay, the syn packet is reinjected to the kernel.

Now you will see the panic like this:
  kernel BUG at net/netfilter/nf_conntrack_extend.c:91!
  Call Trace:
   ? __nf_ct_ext_add_length+0x53/0x3c0 [nf_conntrack]
   init_conntrack+0x12b/0x600 [nf_conntrack]
   nf_conntrack_in+0x4cc/0x580 [nf_conntrack]
   ipv4_conntrack_local+0x48/0x50 [nf_conntrack_ipv4]
   nf_reinject+0x104/0x270
   nfqnl_recv_verdict+0x3e1/0x5f9 [nfnetlink_queue]
   ? nfqnl_recv_verdict+0x5/0x5f9 [nfnetlink_queue]
   ? nla_parse+0xa0/0x100
   nfnetlink_rcv_msg+0x175/0x6a9 [nfnetlink]
   [...]

One possible solution is to make NF_CT_EXT_SYNPROXY extend built-in, i.e.
introduce nf_conntrack_synproxy.c and only do ct extend register and
unregister in it, similar to nf_conntrack_timeout.c.

But having such a obscure restriction of nf_ct_extend_unregister is not a
good idea, so we should invoke synchronize_rcu after set nf_ct_ext_types
to NULL, and check the NULL pointer when do __nf_ct_ext_add_length. Then
it will be easier if we add new ct extend in the future.

Last, we use kfree_rcu to free nf_ct_ext, so rcu_barrier() is unnecessary
anymore, remove it too.
Signed-off-by: NLiping Zhang <zlpnobody@gmail.com>
Acked-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The nf_ct_helper_hash table is protected by nf_ct_helper_mutex, while
nfct_helper operation is protected by nfnl_lock(NFNL_SUBSYS_CTHELPER).
So it's possible that one CPU is walking the nf_ct_helper_hash for
cthelper add/get/del, another cpu is doing nf_conntrack_helpers_unregister
at the same time. This is dangrous, and may cause use after free error.

Note, delete operation will flush all cthelpers added via nfnetlink, so
using rcu to do protect is not easy.

Now introduce a dummy list to record all the cthelpers added via
nfnetlink, then we can walk the dummy list instead of walking the
nf_ct_helper_hash. Also, keep nfnl_cthelper_dump_table unchanged, it
may be invoked without nfnl_lock(NFNL_SUBSYS_CTHELPER) held.
Signed-off-by: NLiping Zhang <zlpnobody@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Otherwise, another CPU may access the invalid pointer. For example:
    CPU0                CPU1
     -              rcu_read_lock();
     -              pfunc = _hook_;
  _hook_ = NULL;          -
  mod unload              -
     -                 pfunc(); // invalid, panic
     -             rcu_read_unlock();

So we must call synchronize_rcu() to wait the rcu reader to finish.

Also note, in nf_nat_snmp_basic_fini, synchronize_rcu() will be invoked
by later nf_conntrack_helper_unregister, but I'm inclined to add a
explicit synchronize_rcu after set the nf_nat_snmp_hook to NULL. Depend
on such obscure assumptions is not a good idea.

Last, in nfnetlink_cttimeout, we use kfree_rcu to free the time object,
so in cttimeout_exit, invoking rcu_barrier() is not necessary at all,
remove it too.
Signed-off-by: NLiping Zhang <zlpnobody@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

We got a report of yet another bug in ping

http://www.openwall.com/lists/oss-security/2017/03/24/6

->disconnect() is not called with socket lock held.

Fix this by acquiring ping rwlock earlier.

Thanks to Daniel, Alexander and Andrey for letting us know this problem.

Fixes: c319b4d7 ("net: ipv4: add IPPROTO_ICMP socket kind")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NDaniel Jiang <danieljiang0415@gmail.com>
Reported-by: NSolar Designer <solar@openwall.com>
Reported-by: NAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Unfortunately too many devices (not under our control) use tcp_tw_recycle=1,
which depends on timestamps being identical of the same saddr.

Although tcp_tw_recycle got removed in net-next we can't make
such end hosts disappear so downgrade to per-host timestamp offsets.

Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Reported-by: NYvan Vanrossomme <yvan@vanrossomme.net>
Fixes: 95a22cae ("tcp: randomize tcp timestamp offsets for each connection")
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change basically codifies what I think was already the limitations on
the busy_poll and busy_read sysctl interfaces.  We weren't checking the
lower bounds and as such could input negative values. The behavior when
that was used was dependent on the architecture. In order to prevent any
issues with that I am just disabling support for values less than 0 since
this way we don't have to worry about any odd behaviors.

By limiting the sysctl values this way it also makes it consistent with how
we handle the SO_BUSY_POLL socket option since the value appears to be
reported as a signed integer value and negative values are rejected.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no reason to continue after a copy_from_user()
failure.

Fixes: ab7ac4eb ("kcm: Kernel Connection Multiplexor module")
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Dmitry posted a nice reproducer of a bug triggering in neigh_probe()
when dereferencing a NULL neigh->ops->solicit method.

This can happen for arp_direct_ops/ndisc_direct_ops and similar,
which can be used for NUD_NOARP neighbours (created when dev->header_ops
is NULL). Admin can then force changing nud_state to some other state
that would fire neigh timer.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Dmitry reported a lockdep splat [1] (false positive) that we can fix
by releasing the spinlock before calling icmp_send() from ip_expire()

This is a false positive because sending an ICMP message can not
possibly re-enter the IP frag engine.

[1]
[ INFO: possible circular locking dependency detected ]
4.10.0+ #29 Not tainted
-------------------------------------------------------
modprobe/12392 is trying to acquire lock:
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] spin_lock
include/linux/spinlock.h:299 [inline]
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] __netif_tx_lock
include/linux/netdevice.h:3486 [inline]
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>]
sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180

but task is already holding lock:
 (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock
include/linux/spinlock.h:299 [inline]
 (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>]
ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&(&q->lock)->rlock){+.-...}:
       validate_chain kernel/locking/lockdep.c:2267 [inline]
       __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
       lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
       spin_lock include/linux/spinlock.h:299 [inline]
       ip_defrag+0x3a2/0x4130 net/ipv4/ip_fragment.c:669
       ip_check_defrag+0x4e3/0x8b0 net/ipv4/ip_fragment.c:713
       packet_rcv_fanout+0x282/0x800 net/packet/af_packet.c:1459
       deliver_skb net/core/dev.c:1834 [inline]
       dev_queue_xmit_nit+0x294/0xa90 net/core/dev.c:1890
       xmit_one net/core/dev.c:2903 [inline]
       dev_hard_start_xmit+0x16b/0xab0 net/core/dev.c:2923
       sch_direct_xmit+0x31f/0x6d0 net/sched/sch_generic.c:182
       __dev_xmit_skb net/core/dev.c:3092 [inline]
       __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
       dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
       neigh_resolve_output+0x6b9/0xb10 net/core/neighbour.c:1308
       neigh_output include/net/neighbour.h:478 [inline]
       ip_finish_output2+0x8b8/0x15a0 net/ipv4/ip_output.c:228
       ip_do_fragment+0x1d93/0x2720 net/ipv4/ip_output.c:672
       ip_fragment.constprop.54+0x145/0x200 net/ipv4/ip_output.c:545
       ip_finish_output+0x82d/0xe10 net/ipv4/ip_output.c:314
       NF_HOOK_COND include/linux/netfilter.h:246 [inline]
       ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
       dst_output include/net/dst.h:486 [inline]
       ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
       ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
       ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
       raw_sendmsg+0x26de/0x3a00 net/ipv4/raw.c:655
       inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:761
       sock_sendmsg_nosec net/socket.c:633 [inline]
       sock_sendmsg+0xca/0x110 net/socket.c:643
       ___sys_sendmsg+0x4a3/0x9f0 net/socket.c:1985
       __sys_sendmmsg+0x25c/0x750 net/socket.c:2075
       SYSC_sendmmsg net/socket.c:2106 [inline]
       SyS_sendmmsg+0x35/0x60 net/socket.c:2101
       do_syscall_64+0x2e8/0x930 arch/x86/entry/common.c:281
       return_from_SYSCALL_64+0x0/0x7a

-> #0 (_xmit_ETHER#2){+.-...}:
       check_prev_add kernel/locking/lockdep.c:1830 [inline]
       check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940
       validate_chain kernel/locking/lockdep.c:2267 [inline]
       __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
       lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
       spin_lock include/linux/spinlock.h:299 [inline]
       __netif_tx_lock include/linux/netdevice.h:3486 [inline]
       sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180
       __dev_xmit_skb net/core/dev.c:3092 [inline]
       __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
       dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
       neigh_hh_output include/net/neighbour.h:468 [inline]
       neigh_output include/net/neighbour.h:476 [inline]
       ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228
       ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316
       NF_HOOK_COND include/linux/netfilter.h:246 [inline]
       ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
       dst_output include/net/dst.h:486 [inline]
       ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
       ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
       ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
       icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394
       icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754
       ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239
       call_timer_fn+0x241/0x820 kernel/time/timer.c:1268
       expire_timers kernel/time/timer.c:1307 [inline]
       __run_timers+0x960/0xcf0 kernel/time/timer.c:1601
       run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614
       __do_softirq+0x31f/0xbe7 kernel/softirq.c:284
       invoke_softirq kernel/softirq.c:364 [inline]
       irq_exit+0x1cc/0x200 kernel/softirq.c:405
       exiting_irq arch/x86/include/asm/apic.h:657 [inline]
       smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962
       apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707
       __read_once_size include/linux/compiler.h:254 [inline]
       atomic_read arch/x86/include/asm/atomic.h:26 [inline]
       rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline]
       __rcu_is_watching kernel/rcu/tree.c:1133 [inline]
       rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147
       rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293
       radix_tree_deref_slot include/linux/radix-tree.h:238 [inline]
       filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335
       do_fault_around mm/memory.c:3231 [inline]
       do_read_fault mm/memory.c:3265 [inline]
       do_fault+0xbd5/0x2080 mm/memory.c:3370
       handle_pte_fault mm/memory.c:3600 [inline]
       __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714
       handle_mm_fault+0x1e2/0x480 mm/memory.c:3751
       __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397
       do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460
       page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&(&q->lock)->rlock);
                               lock(_xmit_ETHER#2);
                               lock(&(&q->lock)->rlock);
  lock(_xmit_ETHER#2);

 *** DEADLOCK ***

10 locks held by modprobe/12392:
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff81329758>]
__do_page_fault+0x2b8/0xb60 arch/x86/mm/fault.c:1336
 #1:  (rcu_read_lock){......}, at: [<ffffffff8188cab6>]
filemap_map_pages+0x1e6/0x1570 mm/filemap.c:2324
 #2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
spin_lock include/linux/spinlock.h:299 [inline]
 #2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
pte_alloc_one_map mm/memory.c:2944 [inline]
 #2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
alloc_set_pte+0x13b8/0x1b90 mm/memory.c:3072
 #3:  (((&q->timer))){+.-...}, at: [<ffffffff81627e72>]
lockdep_copy_map include/linux/lockdep.h:175 [inline]
 #3:  (((&q->timer))){+.-...}, at: [<ffffffff81627e72>]
call_timer_fn+0x1c2/0x820 kernel/time/timer.c:1258
 #4:  (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock
include/linux/spinlock.h:299 [inline]
 #4:  (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>]
ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201
 #5:  (rcu_read_lock){......}, at: [<ffffffff8389a633>]
ip_expire+0x1b3/0x6c0 net/ipv4/ip_fragment.c:216
 #6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] spin_trylock
include/linux/spinlock.h:309 [inline]
 #6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] icmp_xmit_lock
net/ipv4/icmp.c:219 [inline]
 #6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>]
icmp_send+0x803/0x1c80 net/ipv4/icmp.c:681
 #7:  (rcu_read_lock_bh){......}, at: [<ffffffff838ab9a1>]
ip_finish_output2+0x2c1/0x15a0 net/ipv4/ip_output.c:198
 #8:  (rcu_read_lock_bh){......}, at: [<ffffffff836d1dee>]
__dev_queue_xmit+0x23e/0x1e60 net/core/dev.c:3324
 #9:  (dev->qdisc_running_key ?: &qdisc_running_key){+.....}, at:
[<ffffffff836d3a27>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3423

stack backtrace:
CPU: 0 PID: 12392 Comm: modprobe Not tainted 4.10.0+ #29
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x2ee/0x3ef lib/dump_stack.c:52
 print_circular_bug+0x307/0x3b0 kernel/locking/lockdep.c:1204
 check_prev_add kernel/locking/lockdep.c:1830 [inline]
 check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940
 validate_chain kernel/locking/lockdep.c:2267 [inline]
 __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:299 [inline]
 __netif_tx_lock include/linux/netdevice.h:3486 [inline]
 sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180
 __dev_xmit_skb net/core/dev.c:3092 [inline]
 __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
 neigh_hh_output include/net/neighbour.h:468 [inline]
 neigh_output include/net/neighbour.h:476 [inline]
 ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228
 ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:246 [inline]
 ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
 dst_output include/net/dst.h:486 [inline]
 ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
 icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394
 icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754
 ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239
 call_timer_fn+0x241/0x820 kernel/time/timer.c:1268
 expire_timers kernel/time/timer.c:1307 [inline]
 __run_timers+0x960/0xcf0 kernel/time/timer.c:1601
 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614
 __do_softirq+0x31f/0xbe7 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1cc/0x200 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:657 [inline]
 smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962
 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707
RIP: 0010:__read_once_size include/linux/compiler.h:254 [inline]
RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:26 [inline]
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline]
RIP: 0010:__rcu_is_watching kernel/rcu/tree.c:1133 [inline]
RIP: 0010:rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147
RSP: 0000:ffff8801c391f120 EFLAGS: 00000a03 ORIG_RAX: ffffffffffffff10
RAX: dffffc0000000000 RBX: ffff8801c391f148 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 000055edd4374000 RDI: ffff8801dbe1ae0c
RBP: ffff8801c391f1a0 R08: 0000000000000002 R09: 0000000000000000
R10: dffffc0000000000 R11: 0000000000000002 R12: 1ffff10038723e25
R13: ffff8801dbe1ae00 R14: ffff8801c391f680 R15: dffffc0000000000
 </IRQ>
 rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293
 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline]
 filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335
 do_fault_around mm/memory.c:3231 [inline]
 do_read_fault mm/memory.c:3265 [inline]
 do_fault+0xbd5/0x2080 mm/memory.c:3370
 handle_pte_fault mm/memory.c:3600 [inline]
 __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714
 handle_mm_fault+0x1e2/0x480 mm/memory.c:3751
 __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397
 do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460
 page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011
RIP: 0033:0x7f83172f2786
RSP: 002b:00007fffe859ae80 EFLAGS: 00010293
RAX: 000055edd4373040 RBX: 00007f83175111c8 RCX: 000055edd4373238
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f8317510970
RBP: 00007fffe859afd0 R08: 0000000000000009 R09: 0000000000000000
R10: 0000000000000064 R11: 0000000000000000 R12: 000055edd4373040
R13: 0000000000000000 R14: 00007fffe859afe8 R15: 0000000000000000
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

icsk_ack.lrcvtime has a 0 value at socket creation time.

tcpi_last_data_recv can have bogus value if no payload is ever received.

This patch initializes icsk_ack.lrcvtime for active sessions
in tcp_finish_connect(), and for passive sessions in
tcp_create_openreq_child()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 2ae0f17d ("genetlink: use idr to track families") replaced

	if (++n < fams_to_skip)
		continue;
into:

	if (n++ < fams_to_skip)
		continue;

This subtle change cause that on retry ctrl_dumpfamily() call we omit
one family that failed to do ctrl_fill_info() on previous call, because
cb->args[0] = n number counts also family that failed to do
ctrl_fill_info().

Patch fixes the problem and avoid confusion in the future just decrease
n counter when ctrl_fill_info() fail.

User visible problem caused by this bug is failure to get access to
some genetlink family i.e. nl80211. However problem is reproducible
only if number of registered genetlink families is big enough to
cause second call of ctrl_dumpfamily().

Cc: Xose Vazquez Perez <xose.vazquez@gmail.com>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Johannes Berg <johannes@sipsolutions.net>
Fixes: 2ae0f17d ("genetlink: use idr to track families")
Signed-off-by: NStanislaw Gruszka <sgruszka@redhat.com>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In sk_clone_lock(), we create a new socket and inherit most of the
parent's members via sock_copy() which memcpy()'s various sections.
Now, in case the parent socket had a BPF socket filter attached,
then newsk->sk_filter points to the same instance as the original
sk->sk_filter.

sk_filter_charge() is then called on the newsk->sk_filter to take a
reference and should that fail due to hitting max optmem, we bail
out and release the newsk instance.

The issue is that commit 278571ba ("net: filter: simplify socket
charging") wrongly combined the dismantle path with the failure path
of xfrm_sk_clone_policy(). This means, even when charging failed, we
call sk_free_unlock_clone() on the newsk, which then still points to
the same sk_filter as the original sk.

Thus, sk_free_unlock_clone() calls into __sk_destruct() eventually
where it tests for present sk_filter and calls sk_filter_uncharge()
on it, which potentially lets sk_omem_alloc wrap around and releases
the eBPF prog and sk_filter structure from the (still intact) parent.

Fix it by making sure that when sk_filter_charge() failed, we reset
newsk->sk_filter back to NULL before passing to sk_free_unlock_clone(),
so that we don't mess with the parents sk_filter.

Only if xfrm_sk_clone_policy() fails, we did reach the point where
either the parent's filter was NULL and as a result newsk's as well
or where we previously had a successful sk_filter_charge(), thus for
that case, we do need sk_filter_uncharge() to release the prior taken
reference on sk_filter.

Fixes: 278571ba ("net: filter: simplify socket charging")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Alexander reported a KMSAN splat caused by reads of uninitialized
field (tb_id_in) from user provided struct fib_result_nl

It turns out nl_fib_input() sanity tests on user input is a bit
wrong :

User can pretend nlh->nlmsg_len is big enough, but provide
at sendmsg() time a too small buffer.
Reported-by: NAlexander Potapenko <glider@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the case udp_sk(sk)->pending is AF_INET6, udpv6_sendmsg() would
jump to do_append_data, skipping the initialization of sockc.tsflags.
Fix the problem by moving sockc.tsflags initialization earlier.

The bug was detected with KMSAN.

Fixes: c14ac945 ("sock: enable timestamping using control messages")
Signed-off-by: NAlexander Potapenko <glider@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Until now, tipc_nametbl_unsubscribe() is called at subscriptions
reference count cleanup. Usually the subscriptions cleanup is
called at subscription timeout or at subscription cancel or at
subscriber delete.

We have ignored the possibility of this being called from other
locations, which causes deadlock as we try to grab the
tn->nametbl_lock while holding it already.

   CPU1:                             CPU2:
----------                     ----------------
tipc_nametbl_publish
spin_lock_bh(&tn->nametbl_lock)
tipc_nametbl_insert_publ
tipc_nameseq_insert_publ
tipc_subscrp_report_overlap
tipc_subscrp_get
tipc_subscrp_send_event
                             tipc_close_conn
                             tipc_subscrb_release_cb
                             tipc_subscrb_delete
                             tipc_subscrp_put
tipc_subscrp_put
tipc_subscrp_kref_release
tipc_nametbl_unsubscribe
spin_lock_bh(&tn->nametbl_lock)
<<grab nametbl_lock again>>

   CPU1:                              CPU2:
----------                     ----------------
tipc_nametbl_stop
spin_lock_bh(&tn->nametbl_lock)
tipc_purge_publications
tipc_nameseq_remove_publ
tipc_subscrp_report_overlap
tipc_subscrp_get
tipc_subscrp_send_event
                             tipc_close_conn
                             tipc_subscrb_release_cb
                             tipc_subscrb_delete
                             tipc_subscrp_put
tipc_subscrp_put
tipc_subscrp_kref_release
tipc_nametbl_unsubscribe
spin_lock_bh(&tn->nametbl_lock)
<<grab nametbl_lock again>>

In this commit, we advance the calling of tipc_nametbl_unsubscribe()
from the refcount cleanup to the intended callers.

Fixes: d094c4d5 ("tipc: add subscription refcount to avoid invalid delete")
Reported-by: NJohn Thompson <thompa.atl@gmail.com>
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the unnecessary temporary variable 'err' from
sctp_association_init.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The net_cls controller controls the classid field of each socket which
is associated with the cgroup.  Because the classid is per-socket
attribute, when a task migrates to another cgroup or the configured
classid of the cgroup changes, the controller needs to walk all
sockets and update the classid value, which was implemented by
3b13758f ("cgroups: Allow dynamically changing net_classid").

While the approach is not scalable, migrating tasks which have a lot
of fds attached to them is rare and the cost is born by the ones
initiating the operations.  However, for simplicity, both the
migration and classid config change paths call update_classid() which
scans all fds of all tasks in the target css.  This is an overkill for
the migration path which only needs to cover a much smaller subset of
tasks which are actually getting migrated in.

On cgroup v1, this can lead to unexpected scalability issues when one
tries to migrate a task or process into a net_cls cgroup which already
contains a lot of fds.  Even if the migration traget doesn't have many
to get scanned, update_classid() ends up scanning all fds in the
target cgroup which can be extremely numerous.

Unfortunately, on cgroup v2 which doesn't use net_cls, the problem is
even worse.  Before bfc2cf6f ("cgroup: call subsys->*attach() only
for subsystems which are actually affected by migration"), cgroup core
would call the ->css_attach callback even for controllers which don't
see actual migration to a different css.

As net_cls is always disabled but still mounted on cgroup v2, whenever
a process is migrated on the cgroup v2 hierarchy, net_cls sees
identity migration from root to root and cgroup core used to call
->css_attach callback for those.  The net_cls ->css_attach ends up
calling update_classid() on the root net_cls css to which all
processes on the system belong to as the controller isn't used.  This
makes any cgroup v2 migration O(total_number_of_fds_on_the_system)
which is horrible and easily leads to noticeable stalls triggering RCU
stall warnings and so on.

The worst symptom is already fixed in upstream by bfc2cf6f
("cgroup: call subsys->*attach() only for subsystems which are
actually affected by migration"); however, backporting that commit is
too invasive and we want to avoid other cases too.

This patch updates net_cls's cgrp_attach() to iterate fds of only the
processes which are actually getting migrated.  This removes the
surprising migration cost which is dependent on the total number of
fds in the target cgroup.  As this leaves write_classid() the only
user of update_classid(), open-code the helper into write_classid().
Reported-by: NDavid Goode <dgoode@fb.com>
Fixes: 3b13758f ("cgroups: Allow dynamically changing net_classid")
Cc: stable@vger.kernel.org # v4.4+
Cc: Nina Schiff <ninasc@fb.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We have memory leaks of nf_conntrack_helper & expect_policy.
Signed-off-by: NJeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

We only allow runtime updates of expectation policies for timeout and
maximum number of expectations, otherwise reject the update.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Acked-by: NLiping Zhang <zlpnobody@gmail.com>