linux.git/include/net, branch v5.0.4

Bluetooth: Fix locking in bt_accept_enqueue() for BH context

2019-03-10T06:09:01+00:00

commit c4f5627f7eeecde1bb6b646d8c0907b96dc2b2a6 upstream.

With commit e16337622016 ("Bluetooth: Handle bt_accept_enqueue() socket
atomically") lock_sock[_nested]() is used to acquire the socket lock
before manipulating the socket. lock_sock[_nested]() may block, which
is problematic since bt_accept_enqueue() can be called in bottom half
context (e.g. from rfcomm_connect_ind()):

[] __might_sleep+0x4c/0x80
[] lock_sock_nested+0x24/0x58
[] bt_accept_enqueue+0x48/0xd4 [bluetooth]
[] rfcomm_connect_ind+0x190/0x218 [rfcomm]

Add a parameter to bt_accept_enqueue() to indicate whether the
function is called from BH context, and acquire the socket lock
with bh_lock_sock_nested() if that's the case.

Also adapt all callers of bt_accept_enqueue() to pass the new
parameter:

- l2cap_sock_new_connection_cb()
  - uses lock_sock() to lock the parent socket => process context

- rfcomm_connect_ind()
  - acquires the parent socket lock with bh_lock_sock() => BH
    context

- __sco_chan_add()
  - called from sco_chan_add(), which is called from sco_connect().
    parent is NULL, hence bt_accept_enqueue() isn't called in this
    code path and we can ignore it
  - also called from sco_conn_ready(). uses bh_lock_sock() to acquire
    the parent lock => BH context

Fixes: e16337622016 ("Bluetooth: Handle bt_accept_enqueue() socket atomically")
Signed-off-by: Matthias Kaehlcke 
Reviewed-by: Douglas Anderson 
Signed-off-by: Marcel Holtmann 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

net: sched: put back q.qlen into a single location

2019-03-10T06:08:59+00:00

[ Upstream commit 46b1c18f9deb326a7e18348e668e4c7ab7c7458b ]

In the series fc8b81a5981f ("Merge branch 'lockless-qdisc-series'")
John made the assumption that the data path had no need to read
the qdisc qlen (number of packets in the qdisc).

It is true when pfifo_fast is used as the root qdisc, or as direct MQ/MQPRIO
children.

But pfifo_fast can be used as leaf in class full qdiscs, and existing
logic needs to access the child qlen in an efficient way.

HTB breaks badly, since it uses cl->leaf.q->q.qlen in :
  htb_activate() -> WARN_ON()
  htb_dequeue_tree() to decide if a class can be htb_deactivated
  when it has no more packets.

HFSC, DRR, CBQ, QFQ have similar issues, and some calls to
qdisc_tree_reduce_backlog() also read q.qlen directly.

Using qdisc_qlen_sum() (which iterates over all possible cpus)
in the data path is a non starter.

It seems we have to put back qlen in a central location,
at least for stable kernels.

For all qdisc but pfifo_fast, qlen is guarded by the qdisc lock,
so the existing q.qlen{++|--} are correct.

For 'lockless' qdisc (pfifo_fast so far), we need to use atomic_{inc|dec}()
because the spinlock might be not held (for example from
pfifo_fast_enqueue() and pfifo_fast_dequeue())

This patch adds atomic_qlen (in the same location than qlen)
and renames the following helpers, since we want to express
they can be used without qdisc lock, and that qlen is no longer percpu.

- qdisc_qstats_cpu_qlen_dec -> qdisc_qstats_atomic_qlen_dec()
- qdisc_qstats_cpu_qlen_inc -> qdisc_qstats_atomic_qlen_inc()

Later (net-next) we might revert this patch by tracking all these
qlen uses and replace them by a more efficient method (not having
to access a precise qlen, but an empty/non_empty status that might
be less expensive to maintain/track).

Another possibility is to have a legacy pfifo_fast version that would
be used when used a a child qdisc, since the parent qdisc needs
a spinlock anyway. But then, future lockless qdiscs would also
have the same problem.

Fixes: 7e66016f2c65 ("net: sched: helpers to sum qlen and qlen for per cpu logic")
Signed-off-by: Eric Dumazet 
Cc: John Fastabend 
Cc: Jamal Hadi Salim 
Cc: Cong Wang 
Cc: Jiri Pirko 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: Add ICMPv6 support when parse route ipproto

2019-03-02T00:41:27+00:00

For ip rules, we need to use 'ipproto ipv6-icmp' to match ICMPv6 headers.
But for ip -6 route, currently we only support tcp, udp and icmp.

Add ICMPv6 support so we can match ipv6-icmp rules for route lookup.

v2: As David Ahern and Sabrina Dubroca suggested, Add an argument to
rtm_getroute_parse_ip_proto() to handle ICMP/ICMPv6 with different family.

Reported-by: Jianlin Shi 
Fixes: eacb9384a3fe ("ipv6: support sport, dport and ip_proto in RTM_GETROUTE")
Signed-off-by: Hangbin Liu 
Signed-off-by: David S. Miller

net: avoid use IPCB in cipso_v4_error

2019-02-25T22:32:35+00:00

Extract IP options in cipso_v4_error and use __icmp_send.

Signed-off-by: Sergey Nazarov 
Acked-by: Paul Moore 
Signed-off-by: David S. Miller

net: Add __icmp_send helper.

2019-02-25T22:32:35+00:00

Add __icmp_send function having ip_options struct parameter

Signed-off-by: Sergey Nazarov 
Reviewed-by: Paul Moore 
Signed-off-by: David S. Miller

phonet: fix building with clang

2019-02-22T00:23:56+00:00

clang warns about overflowing the data[] member in the struct pnpipehdr:

net/phonet/pep.c:295:8: warning: array index 4 is past the end of the array (which contains 1 element) [-Warray-bounds]
                        if (hdr->data[4] == PEP_IND_READY)
                            ^         ~
include/net/phonet/pep.h:66:3: note: array 'data' declared here
                u8              data[1];

Using a flexible array member at the end of the struct avoids the
warning, but since we cannot have a flexible array member inside
of the union, each index now has to be moved back by one, which
makes it a little uglier.

Signed-off-by: Arnd Bergmann 
Acked-by: Rémi Denis-Courmont 
Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2019-02-22T00:08:52+00:00

Steffen Klassert says:

====================
pull request (net): ipsec 2019-02-21

1) Don't do TX bytes accounting for the esp trailer when sending
   from a request socket as this will result in an out of bounds
   memory write. From Martin Willi.

2) Destroy xfrm_state synchronously on net exit path to
   avoid nested gc flush callbacks that may trigger a
   warning in xfrm6_tunnel_net_exit(). From Cong Wang.

3) Do an unconditionally clone in pfkey_broadcast_one()
   to avoid a race when freeing the skb.
   From Sean Tranchetti.

4) Fix inbound traffic via XFRM interfaces across network
   namespaces. We did the lookup for interfaces and policies
   in the wrong namespace. From Tobias Brunner.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller

net: fix possible overflow in __sk_mem_raise_allocated()

2019-02-14T05:05:18+00:00

With many active TCP sockets, fat TCP sockets could fool
__sk_mem_raise_allocated() thanks to an overflow.

They would increase their share of the memory, instead
of decreasing it.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: ipv4: use a dedicated counter for icmp_v4 redirect packets

2019-02-09T05:50:15+00:00

According to the algorithm described in the comment block at the
beginning of ip_rt_send_redirect, the host should try to send
'ip_rt_redirect_number' ICMP redirect packets with an exponential
backoff and then stop sending them at all assuming that the destination
ignores redirects.
If the device has previously sent some ICMP error packets that are
rate-limited (e.g TTL expired) and continues to receive traffic,
the redirect packets will never be transmitted. This happens since
peer->rate_tokens will be typically greater than 'ip_rt_redirect_number'
and so it will never be reset even if the redirect silence timeout
(ip_rt_redirect_silence) has elapsed without receiving any packet
requiring redirects.

Fix it by using a dedicated counter for the number of ICMP redirect
packets that has been sent by the host

I have not been able to identify a given commit that introduced the
issue since ip_rt_send_redirect implements the same rate-limiting
algorithm from commit 1da177e4c3f4 ("Linux-2.6.12-rc2")

Signed-off-by: Lorenzo Bianconi 
Signed-off-by: David S. Miller

xfrm: destroy xfrm_state synchronously on net exit path

2019-02-05T05:29:20+00:00

xfrm_state_put() moves struct xfrm_state to the GC list
and schedules the GC work to clean it up. On net exit call
path, xfrm_state_flush() is called to clean up and
xfrm_flush_gc() is called to wait for the GC work to complete
before exit.

However, this doesn't work because one of the ->destructor(),
ipcomp_destroy(), schedules the same GC work again inside
the GC work. It is hard to wait for such a nested async
callback. This is also why syzbot still reports the following
warning:

 WARNING: CPU: 1 PID: 33 at net/ipv6/xfrm6_tunnel.c:351 xfrm6_tunnel_net_exit+0x2cb/0x500 net/ipv6/xfrm6_tunnel.c:351
 ...
  ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:153
  cleanup_net+0x51d/0xb10 net/core/net_namespace.c:551
  process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153
  worker_thread+0x143/0x14a0 kernel/workqueue.c:2296
  kthread+0x357/0x430 kernel/kthread.c:246
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

In fact, it is perfectly fine to bypass GC and destroy xfrm_state
synchronously on net exit call path, because it is in process context
and doesn't need a work struct to do any blocking work.

This patch introduces xfrm_state_put_sync() which simply bypasses
GC, and lets its callers to decide whether to use this synchronous
version. On net exit path, xfrm_state_fini() and
xfrm6_tunnel_net_exit() use it. And, as ipcomp_destroy() itself is
blocking, it can use xfrm_state_put_sync() directly too.

Also rename xfrm_state_gc_destroy() to ___xfrm_state_destroy() to
reflect this change.

Fixes: b48c05ab5d32 ("xfrm: Fix warning in xfrm6_tunnel_net_exit.")
Reported-and-tested-by: syzbot+e9aebef558e3ed673934@syzkaller.appspotmail.com
Cc: Steffen Klassert 
Signed-off-by: Cong Wang 
Signed-off-by: Steffen Klassert