Its easy to eat all kernel memory and trigger NMI watchdog, using an
exploit program that queues unix sockets on top of others.

lkml ref : http://lkml.org/lkml/2010/11/25/8

This mechanism is used in applications, one choice we have is to have a
recursion limit.

Other limits might be needed as well (if we queue other types of files),
since the passfd mechanism is currently limited by socket receive queue
sizes only.

Add a recursion_level to unix socket, allowing up to 4 levels.

Each time we send an unix socket through sendfd mechanism, we copy its
recursion level (plus one) to receiver. This recursion level is cleared
when socket receive queue is emptied.

Reported-by: Марк Коренберг <socketpair@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

jiffies is defined as "volatile".

  extern unsigned long volatile __jiffy_data jiffies;

ACCESS_ONCE() uses "volatile".
As a result, some compilers warn duplicate `volatile' for ACCESS_ONCE(jiffies).

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

WIPHY_FLAG_IBSS_RSN is BIT(7) as is WIPHY_FLAG_CONTROL_PORT_PROTOCOL. Change
to BIT(8).

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

When b43legacy is compiled on the arm platform, the following errors are seen:

  CC [M]  drivers/net/wireless/b43legacy/xmit.o
In file included from include/net/dst.h:11,
from drivers/net/wireless/b43legacy/xmit.c:31:
include/net/dst_ops.h:28: error: expected ':', ',', ';', '}' or '__attribute__'
   before '____cacheline_aligned_in_smp'
include/net/dst_ops.h: In function 'dst_entries_get_fast':
include/net/dst_ops.h:33: error: 'struct dst_ops' has no member named
   'pcpuc_entries'
include/net/dst_ops.h: In function 'dst_entries_get_slow':
include/net/dst_ops.h:41: error: 'struct dst_ops' has no member named
   'pcpuc_entries'
include/net/dst_ops.h: In function 'dst_entries_add':
include/net/dst_ops.h:49: error: 'struct dst_ops' has no member named
   'pcpuc_entries'
include/net/dst_ops.h: In function 'dst_entries_init':
include/net/dst_ops.h:55: error: 'struct dst_ops' has no member named
   'pcpuc_entries'
include/net/dst_ops.h: In function 'dst_entries_destroy':
include/net/dst_ops.h:60: error: 'struct dst_ops' has no member named
   'pcpuc_entries'
make[4]: *** [drivers/net/wireless/b43legacy/xmit.o] Error 1
make[3]: *** [drivers/net/wireless/b43legacy] Error 2
make[2]: *** [drivers/net/wireless] Error 2
make[1]: *** [drivers/net] Error 2
make: *** [drivers] Error 2

The cause is a missing include of <linux/cache.h>, which is present for
i386 and x86_64 architectures, but not for arm.

Signed-off-by: Arnd Hannemann <arnd@arndnet.de>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@kernel.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (66 commits)
  can-bcm: fix minor heap overflow
  gianfar: Do not call device_set_wakeup_enable() under a spinlock
  ipv6: Warn users if maximum number of routes is reached.
  docs: Add neigh/gc_thresh3 and route/max_size documentation.
  axnet_cs: fix resume problem for some Ax88790 chip
  ipv6: addrconf: don't remove address state on ifdown if the address is being kept
  tcp: Don't change unlocked socket state in tcp_v4_err().
  x25: Prevent crashing when parsing bad X.25 facilities
  cxgb4vf: add call to Firmware to reset VF State.
  cxgb4vf: Fail open if link_start() fails.
  cxgb4vf: flesh out PCI Device ID Table ...
  cxgb4vf: fix some errors in Gather List to skb conversion
  cxgb4vf: fix bug in Generic Receive Offload
  cxgb4vf: don't implement trivial (and incorrect) ndo_select_queue()
  ixgbe: Look inside vlan when determining offload protocol.
  bnx2x: Look inside vlan when determining checksum proto.
  vlan: Add function to retrieve EtherType from vlan packets.
  virtio-net: init link state correctly
  ucc_geth: Fix deadlock
  ucc_geth: Do not bring the whole IF down when TX failure.
  ...

Robin Holt tried to boot a 16TB machine and found some limits were
reached : sysctl_tcp_mem[2], sysctl_udp_mem[2]

We can switch infrastructure to use long "instead" of "int", now
atomic_long_t primitives are available for free.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reported-by: Robin Holt <holt@sgi.com>
Reviewed-by: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Presently the b43legacy build fails on an sh randconfig:

In file included from include/net/dst.h:12,
                 from drivers/net/wireless/b43legacy/xmit.c:32:
include/net/dst_ops.h:28: error: expected ':', ',', ';', '}' or '__attribute__' before '____cacheline_aligned_in_smp'
include/net/dst_ops.h: In function 'dst_entries_get_fast':
include/net/dst_ops.h:33: error: 'struct dst_ops' has no member named 'pcpuc_entries'
include/net/dst_ops.h: In function 'dst_entries_get_slow':
include/net/dst_ops.h:41: error: 'struct dst_ops' has no member named 'pcpuc_entries'
include/net/dst_ops.h: In function 'dst_entries_add':
include/net/dst_ops.h:49: error: 'struct dst_ops' has no member named 'pcpuc_entries'
include/net/dst_ops.h: In function 'dst_entries_init':
include/net/dst_ops.h:55: error: 'struct dst_ops' has no member named 'pcpuc_entries'
include/net/dst_ops.h: In function 'dst_entries_destroy':
include/net/dst_ops.h:60: error: 'struct dst_ops' has no member named 'pcpuc_entries'
make[5]: *** [drivers/net/wireless/b43legacy/xmit.o] Error 1
make[5]: *** Waiting for unfinished jobs....

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (41 commits)
  inet_diag: Make sure we actually run the same bytecode we audited.
  netlink: Make nlmsg_find_attr take a const nlmsghdr*.
  fib: fib_result_assign() should not change fib refcounts
  netfilter: ip6_tables: fix information leak to userspace
  cls_cgroup: Fix crash on module unload
  memory corruption in X.25 facilities parsing
  net dst: fix percpu_counter list corruption and poison overwritten
  rds: Remove kfreed tcp conn from list
  rds: Lost locking in loop connection freeing
  de2104x: fix panic on load
  atl1 : fix panic on load
  netxen: remove unused firmware exports
  caif: Remove noisy printout when disconnecting caif socket
  caif: SPI-driver bugfix - incorrect padding.
  caif: Bugfix for socket priority, bindtodev and dbg channel.
  smsc911x: Set Ethernet EEPROM size to supported device's size
  ipv4: netfilter: ip_tables: fix information leak to userland
  ipv4: netfilter: arp_tables: fix information leak to userland
  cxgb4vf: remove call to stop TX queues at load time.
  cxgb4: remove call to stop TX queues at load time.
  ...

This will let us use it on a nlmsghdr stored inside a netlink_callback.

Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Signed-off-by: David S. Miller <davem@davemloft.net>