When a VLAN interface (on top of batX) is removed and
re-added within a short timeframe TT does not have enough
time to properly cleanup. This creates an internal TT state
mismatch as the newly created softif_vlan will be
initialized from scratch with a TT client count of zero
(even if TT entries for this VLAN still exist). The
resulting TT messages are bogus due to the counter / tt
client listing mismatch, thus creating inconsistencies on
every node in the network

To fix this issue destroy_vlan() has to not free the VLAN
object immediately but it has to be kept alive until all the
TT entries for this VLAN have been removed. destroy_vlan()
still removes the sysfs folder so that the user has the
feeling that everything went fine.

If the same VLAN is re-added before the old object is free'd,
then the latter is resurrected and re-used.

Implement such behaviour by increasing the reference counter
of a softif_vlan object every time a new local TT entry for
such VLAN is created and remove the object from the list
only when all the TT entries have been destroyed.
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

Since bridge loop avoidance only supports untagged or simple 802.1q
tagged VLAN claim frames, claim frames with stacked VLAN headers (QinQ)
should be detected and dropped. Transporting the over the mesh may cause
problems on the receivers, or create bogus entries in the local tt
tables.
Reported-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

*_result[len] is parsed as *(_result[len]) which is not at all what we
want to touch here.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: 84a7c0b1 ("dns_resolver: assure that dns_query() result is null-terminated")
Signed-off-by: David S. Miller <davem@davemloft.net>

Zoltan Kiss says:

====================
xen-netback: Fixing up xenvif_tx_check_gop

This series fixes a lot of bugs on the error path around this function, which
were introduced with my grant mapping series in 3.15. They apply to the latest
net tree, but probably to net-next as well without any modification.
I'll post an another series which applies to 3.15 stable, as the problem was
first discovered there. The only difference is that the "queue" variable name is
replaced to "vif".
====================
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Reported-by: Armin Zentai <armin.zentai@ezit.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>

Due to this pointer is increased prematurely, the error log contains rubbish.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Reported-by: Armin Zentai <armin.zentai@ezit.hu>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch makes this function aware that the first frag and the header might
share the same ring slot. That could happen if the first slot is bigger than
PKT_PROT_LEN. Due to this the error path might release that slot twice or never,
depending on the error scenario.
xenvif_idx_release is also removed from xenvif_idx_unmap, and called separately.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Reported-by: Armin Zentai <armin.zentai@ezit.hu>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: David S. Miller <davem@davemloft.net>

When the grant operations failed, the skb is freed up eventually, and it tries
to release the frags, if there is any. For the main skb nr_frags is set to 0 to
avoid this, but on the frag_list it iterates through the frags array, and tries
to call put_page on the page pointer which contains garbage at that time.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Reported-by: Armin Zentai <armin.zentai@ezit.hu>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: David S. Miller <davem@davemloft.net>

The error handling for skb's with frag_list was completely wrong, it caused
double unmap attempts to happen if the error was on the first skb. Move it to
the right place in the loop.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Reported-by: Armin Zentai <armin.zentai@ezit.hu>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: David S. Miller <davem@davemloft.net>

When kernel generates a handle for a u32 filter, it tries to start
from the max in the bucket. So when we have a filter with the max (fff)
handle, it will cause kernel always generates the same handle for new
filters. This can be shown by the following command:

	tc qdisc add dev eth0 ingress
	tc filter add dev eth0 parent ffff: protocol ip pref 770 handle 800::fff u32 match ip protocol 1 0xff
	tc filter add dev eth0 parent ffff: protocol ip pref 770 u32 match ip protocol 1 0xff
	...

we will get some u32 filters with same handle:

 # tc filter show dev eth0 parent ffff:
filter protocol ip pref 770 u32
filter protocol ip pref 770 u32 fh 800: ht divisor 1
filter protocol ip pref 770 u32 fh 800::fff order 4095 key ht 800 bkt 0
  match 00010000/00ff0000 at 8
filter protocol ip pref 770 u32 fh 800::fff order 4095 key ht 800 bkt 0
  match 00010000/00ff0000 at 8
filter protocol ip pref 770 u32 fh 800::fff order 4095 key ht 800 bkt 0
  match 00010000/00ff0000 at 8
filter protocol ip pref 770 u32 fh 800::fff order 4095 key ht 800 bkt 0
  match 00010000/00ff0000 at 8

handles should be unique. This patch fixes it by looking up a bitmap,
so that can guarantee the handle is as unique as possible. For compatibility,
we still start from 0x800.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Huawei's usage of the subclass and protocol fields is not 100%
clear to us, but there appears to be a very strict system.

A device with the "shared" device ID 12d1:1506 and this NCM
function was recently reported (showing only default altsetting):

    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass      3
      bInterfaceProtocol     22
      iInterface              8 CDC Network Control Model (NCM)
      ** UNRECOGNIZED:  05 24 00 10 01
      ** UNRECOGNIZED:  06 24 1a 00 01 1f
      ** UNRECOGNIZED:  0c 24 1b 00 01 00 04 10 14 dc 05 20
      ** UNRECOGNIZED:  0d 24 0f 0a 0f 00 00 00 ea 05 03 00 01
      ** UNRECOGNIZED:  05 24 06 01 01
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0010  1x 16 bytes
        bInterval               9

Cc: Enrico Mioso <mrkiko.rs@gmail.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add two device IDs found in an out-of-tree driver downloadable
from Netgear.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

If "newmtu * 2 + 4" is too large then it can cause an integer overflow
leading to memory corruption.  Eric Dumazet suggests that 65534 is a
reasonable upper limit.

Btw, "newmtu" is not allowed to be a negative number because of the
check in dev_set_mtu(), so that's ok.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 568f194e ("net: ppp: use
sk_unattached_filter api") inadvertently changed the logic when setting
PPP pass and active filters. This applies to both the generic PPP subsystem
implemented by drivers/net/ppp/ppp_generic.c and the ISDN PPP subsystem
implemented by drivers/isdn/i4l/isdn_ppp.c. The original code in ppp_ioctl()
(or isdn_ppp_ioctl(), resp.) handling PPPIOCSPASS and PPPIOCSACTIVE allowed to
remove a pass/active filter previously set by using a filter of length zero.
However, with the new code this is not possible anymore as this case is not
explicitly checked for, which leads to passing NULL as a filter to
sk_unattached_filter_create(). This results in returning EINVAL to the caller.

Additionally, the variables ppp->pass_filter and ppp->active_filter (or
is->pass_filter and is->active_filter, resp.) are not reset to NULL, although
the filters they point to may have been destroyed by
sk_unattached_filter_destroy(), so in this EINVAL case dangling pointers are
left behind (provided the pointers were previously non-NULL).

This patch corrects both problems by checking whether the filter passed is
empty or non-empty, and prevents sk_unattached_filter_create() from being
called in the first case. Moreover, the pointers are always reset to NULL
as soon as sk_unattached_filter_destroy() returns.
Signed-off-by: Christoph Schulz <develop@kristov.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix a regression introduced by commit 35f6f453 ("net/mlx4_en: Don't use
irq_affinity_notifier to track changes in IRQ affinity map").
When core is started in legacy EQ's (number of IRQ's < rx rings), cq->irq_desc
was NULL.  This caused a kernel crash under heavy traffic - when having more
than rx NAPI budget completions.
Fixed to have it set for both EQ modes.
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Nothing cleans up the objects created by
vnet_new(), they are completely leaked.

vnet_exit(), after doing the vio_unregister_driver() to clean
up ports, should call a helper function that iterates over vnet_list
and cleans up those objects. This includes unregister_netdevice()
as well as free_netdev().
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Reviewed-by: Karl Volz <karl.volz@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The ethernet port on my ASUS A88X Pro mainboard stopped working
several times a day, with messages like these in dmesg:

AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 domain=0x001e address=0x0000000000003000 flags=0x0050]

Searching the web for these messages led me to similar reports about
different hardware supported by r8169, and eventually to commits
3ced8c95 ('r8169: enforce RX_MULTI_EN
for the 8168f.') and eb2dc35d ('r8169:
RxConfig hack for the 8168evl'). So I tried this change, and it fixes
the problem for me.
Signed-off-by: Michel Dänzer <michel@daenzer.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

====================
Netfilter/nf_tables fixes

The following patchset contains nf_tables fixes, they are:

1) Fix wrong transaction handling when the table flags are not
   modified.

2) Fix missing rcu read_lock section in the netlink dump path, which
   is not protected by the nfnl_lock.

3) Set NLM_F_DUMP_INTR in the netlink dump path to indicate
   interferences with updates.

4) Fix 64 bits chain counters when they are retrieved from a 32 bits
   arch, from Eric Dumazet.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixed a bug that was introduced by my GRE-GRO patch
(bf5a755f net-gre-gro: Add GRE
support to the GRO stack) that breaks the forwarding path
because various GSO related fields were not set. The bug will
cause on the egress path either the GSO code to fail, or a
GRE-TSO capable (NETIF_F_GSO_GRE) NICs to choke. The following
fix has been tested for both cases.
Signed-off-by: H.K. Jerry Chu <hkchu@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull MTD fixes from Brian Norris:

 - Fix ELM suspend/resume

 - Reduce warnings if NAND ECC is too weak

 - Add CFI support for Sharp LH28F640BF NOR

   The last fix is coming in because other commits in the 3.16 cycle
   depended on this support.

* tag 'for-linus-20140716' of git://git.infradead.org/linux-mtd:
  mtd: cfi_cmdset_0001.c: add support for Sharp LH28F640BF NOR
  mtd: nand: reduce the warning noise when the ECC is too weak
  mtd: devices: elm: fix elm_context_save() and elm_context_restore() functions

Pull scheduler fixes from Ingo Molnar:
 "A cpufreq lockup fix and a compiler warning fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix compiler warnings
  x86, tsc: Fix cpufreq lockup

Pull perf fixes from Ingo Molnar:
 "Tooling fixes and an Intel PMU driver fixlet"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Do not allow optimized switch for non-cloned events
  perf/x86/intel: ignore CondChgd bit to avoid false NMI handling
  perf symbols: Get kernel start address by symbol name
  perf tools: Fix segfault in cumulative.callchain report

Pull sound fixes from Takashi Iwai:
 "Things seem to calm down so far, just a small few HD-audio fixes
  (regression fixes and a new codec ID addition) popping up"

* tag 'sound-3.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Fix broken PM due to incomplete i915 initialization
  ALSA: hda - Revert stream assignment order for Intel controllers
  ALSA: hda - Add new GPU codec ID 0x10de0070 to snd-hda
  ALSA: hda: Fix build warning

Pull quota fix from Jan Kara:
 "Fix locking of dquot shrinker"

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  quota: missing lock in dqcache_shrink_scan()

Pull GPIO fix from Linus Walleij:
 "Fix up some merge confusion from the merge window"

* tag 'gpio-v3.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: mcp23s08: Eliminates redundant checking.

Commit 1ab6c499 (fs: convert fs shrinkers to new scan/count API)
accidentally removed locking from quota shrinker. Fix it -
dqcache_shrink_scan() should use dq_list_lock to protect the
scan on free_dquots list.

CC: stable@vger.kernel.org
Fixes: 1ab6c499Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>

Pull fuse fixes from Miklos Szeredi:
 "This contains miscellaneous fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: replace count*size kzalloc by kcalloc
  fuse: release temporary page if fuse_writepage_locked() failed
  fuse: restructure ->rename2()
  fuse: avoid scheduling while atomic
  fuse: handle large user and group ID
  fuse: inode: drop cast
  fuse: ignore entry-timeout on LOOKUP_REVAL
  fuse: timeout comparison fix

Pull networking fixes from David Miller:

 1) Bluetooth pairing fixes from Johan Hedberg.

 2) ieee80211_send_auth() doesn't allocate enough tail room for the SKB,
    from Max Stepanov.

 3) New iwlwifi chip IDs, from Oren Givon.

 4) bnx2x driver reads wrong PCI config space MSI register, from Yijing
    Wang.

 5) IPV6 MLD Query validation isn't strong enough, from Hangbin Liu.

 6) Fix double SKB free in openvswitch, from Andy Zhou.

 7) Fix sk_dst_set() being racey with UDP sockets, leading to strange
    crashes, from Eric Dumazet.

 8) Interpret the NAPI budget correctly in the new systemport driver,
    from Florian Fainelli.

 9) VLAN code frees percpu stats in the wrong place, leading to crashes
    in the get stats handler.  From Eric Dumazet.

10) TCP sockets doing a repair can crash with a divide by zero, because
    we invoke tcp_push() with an MSS value of zero.  Just skip that part
    of the sendmsg paths in repair mode.  From Christoph Paasch.

11) IRQ affinity bug fixes in mlx4 driver from Amir Vadai.

12) Don't ignore path MTU icmp messages with a zero mtu, machines out
    there still spit them out, and all of our per-protocol handlers for
    PMTU can cope with it just fine.  From Edward Allcutt.

13) Some NETDEV_CHANGE notifier invocations were not passing in the
    correct kind of cookie as the argument, from Loic Prylli.

14) Fix crashes in long multicast/broadcast reassembly, from Jon Paul
    Maloy.

15) ip_tunnel_lookup() doesn't interpret wildcard keys correctly, fix
    from Dmitry Popov.

16) Fix skb->sk assigned without taking a reference to 'sk' in
    appletalk, from Andrey Utkin.

17) Fix some info leaks in ULP event signalling to userspace in SCTP,
    from Daniel Borkmann.

18) Fix deadlocks in HSO driver, from Olivier Sobrie.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (93 commits)
  hso: fix deadlock when receiving bursts of data
  hso: remove unused workqueue
  net: ppp: don't call sk_chk_filter twice
  mlx4: mark napi id for gro_skb
  bonding: fix ad_select module param check
  net: pppoe: use correct channel MTU when using Multilink PPP
  neigh: sysctl - simplify address calculation of gc_* variables
  net: sctp: fix information leaks in ulpevent layer
  MAINTAINERS: update r8169 maintainer
  net: bcmgenet: fix RGMII_MODE_EN bit
  tipc: clear 'next'-pointer of message fragments before reassembly
  r8152: fix r8152_csum_workaround function
  be2net: set EQ DB clear-intr bit in be_open()
  GRE: enable offloads for GRE
  farsync: fix invalid memory accesses in fst_add_one() and fst_init_card()
  igb: do a reset on SR-IOV re-init if device is down
  igb: Workaround for i210 Errata 25: Slow System Clock
  usbnet: smsc95xx: add reset_resume function with reset operation
  dp83640: Always decode received status frames
  r8169: disable L23
  ...

When the initialization of Intel HDMI controller fails due to missing
i915 kernel symbols (e.g. HD-audio is built in while i915 is module),
the driver discontinues the probe.  However, since the probe was done
asynchronously, the driver object still remains, thus the relevant PM
ops are still called at suspend/resume. This results in the bad access
to the incomplete audio card object, eventually leads to Oops or stall
at PM.

This patch adds the missing checks of chip->init_failed flag at each
PM callback in order to fix the problem above.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=79561
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

When the module sends bursts of data, sometimes a deadlock happens in
the hso driver when the tty buffer doesn't get the chance to be flushed
quickly enough.

Remove the endless while loop in function put_rxbuf_data() which is
called by the urb completion handler.
If there isn't enough room in the tty buffer, discards all the data
received in the URB.

Cc: David Miller <davem@davemloft.net>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Dan Williams <dcbw@redhat.com>
Cc: Jan Dumon <j.dumon@option.com>
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The workqueue "retry_unthrottle_workqueue" is not scheduled anywhere
in the code. So, remove it.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull firewire fix from Stefan Richter:
 "The 1394 drivers cannot and are not supposed to be built on platforms
  which don't provide the DMA mapping API (regression since v3.16-rc1
  with CONFIG_COMPILE_TEST=y on some architectures)"

* tag 'firewire-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: IEEE 1394 (FireWire) support should depend on HAS_DMA

Pull another aio fix from Ben LaHaise:
 "put_reqs_available() can now be called from within irq context, which
  means that it (and its sibling function get_reqs_available()) now need
  to be irq-safe, not just preempt-safe"

* git://git.kvack.org/~bcrl/aio-fixes:
  aio: protect reqs_available updates from changes in interrupt handlers

The l2tp [get|set]sockopt() code has fallen back to the UDP functions
for socket option levels != SOL_PPPOL2TP since day one, but that has
never actually worked, since the l2tp socket isn't an inet socket.

As David Miller points out:

  "If we wanted this to work, it'd have to look up the tunnel and then
   use tunnel->sk, but I wonder how useful that would be"

Since this can never have worked so nobody could possibly have depended
on that functionality, just remove the broken code and return -EINVAL.
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: James Chapman <jchapman@katalix.com>
Acked-by: David Miller <davem@davemloft.net>
Cc: Phil Turnbull <phil.turnbull@oracle.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 568f194e ("net: ppp: use
sk_unattached_filter api") causes sk_chk_filter() to be called twice when
setting a PPP pass or active filter. This applies to both the generic PPP
subsystem implemented by drivers/net/ppp/ppp_generic.c and the ISDN PPP
subsystem implemented by drivers/isdn/i4l/isdn_ppp.c. The first call is from
within get_filter(). The second one is through the call chain

  ppp_ioctl() or isdn_ppp_ioctl()
  --> sk_unattached_filter_create()
      --> __sk_prepare_filter()
          --> sk_chk_filter()

The first call from within get_filter() should be deleted as get_filter() is
called just before calling sk_unattached_filter_create() later on, which
eventually calls sk_chk_filter() anyway.

For 3.15.x, this proposed change is a bugfix rather than a pure optimization as
in that branch, sk_chk_filter() may replace filter codes by other codes which
are not recognized when executing sk_chk_filter() a second time. So with
3.15.x, if sk_chk_filter() is called twice, the second invocation may yield
EINVAL (this depends on the filter codes found in the filter to be set, but
because the replacement is done for frequently used codes, this is almost
always the case). The net effect is that setting pass and/or active PPP filters
does not work anymore, since sk_unattached_filter_create() always returns
EINVAL due to the second call to sk_chk_filter(), regardless whether the filter
was originally sane or not.
Signed-off-by: Christoph Schulz <develop@kristov.de>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Napi id was not marked for gro_skb, this will lead rx busy loop won't
work correctly since they stack never try to call low latency receive
method because of a zero socket napi id. Fix this by marking napi id
for gro_skb.

The transaction rate of 1 byte netperf tcp_rr gets about 50% increased
(from 20531.68 to 30610.88).

Cc: Amir Vadai <amirv@mellanox.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Obvious copy/paste error when I converted the ad_select to the new
option API. "lacp_rate" there should be "ad_select" so we can get the
proper value.

CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@gmail.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: David S. Miller <davem@davemloft.net>

Fixes: 9e5f5eeb ("bonding: convert ad_select to use the new option
API")
Reported-by: Karim Scheik <karim.scheik@prisma-solutions.at>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The PPP channel MTU is used with Multilink PPP when ppp_mp_explode() (see
ppp_generic module) tries to determine how big a fragment might be. According
to RFC 1661, the MTU excludes the 2-byte PPP protocol field, see the
corresponding comment and code in ppp_mp_explode():

		/*
		 * hdrlen includes the 2-byte PPP protocol field, but the
		 * MTU counts only the payload excluding the protocol field.
		 * (RFC1661 Section 2)
		 */
		mtu = pch->chan->mtu - (hdrlen - 2);

However, the pppoe module *does* include the PPP protocol field in the channel
MTU, which is wrong as it causes the PPP payload to be 1-2 bytes too big under
certain circumstances (one byte if PPP protocol compression is used, two
otherwise), causing the generated Ethernet packets to be dropped. So the pppoe
module has to subtract two bytes from the channel MTU. This error only
manifests itself when using Multilink PPP, as otherwise the channel MTU is not
used anywhere.

In the following, I will describe how to reproduce this bug. We configure two
pppd instances for multilink PPP over two PPPoE links, say eth2 and eth3, with
a MTU of 1492 bytes for each link and a MRRU of 2976 bytes. (This MRRU is
computed by adding the two link MTUs and subtracting the MP header twice, which
is 4 bytes long.) The necessary pppd statements on both sides are "multilink
mtu 1492 mru 1492 mrru 2976". On the client side, we additionally need "plugin
rp-pppoe.so eth2" and "plugin rp-pppoe.so eth3", respectively; on the server
side, we additionally need to start two pppoe-server instances to be able to
establish two PPPoE sessions, one over eth2 and one over eth3. We set the MTU
of the PPP network interface to the MRRU (2976) on both sides of the connection
in order to make use of the higher bandwidth. (If we didn't do that, IP
fragmentation would kick in, which we want to avoid.)

Now we send a ICMPv4 echo request with a payload of 2948 bytes from client to
server over the PPP link. This results in the following network packet:

   2948 (echo payload)
 +    8 (ICMPv4 header)
 +   20 (IPv4 header)
---------------------
   2976 (PPP payload)

These 2976 bytes do not exceed the MTU of the PPP network interface, so the
IP packet is not fragmented. Now the multilink PPP code in ppp_mp_explode()
prepends one protocol byte (0x21 for IPv4), making the packet one byte bigger
than the negotiated MRRU. So this packet would have to be divided in three
fragments. But this does not happen as each link MTU is assumed to be two bytes
larger. So this packet is diveded into two fragments only, one of size 1489 and
one of size 1488. Now we have for that bigger fragment:

   1489 (PPP payload)
 +    4 (MP header)
 +    2 (PPP protocol field for the MP payload (0x3d))
 +    6 (PPPoE header)
--------------------------
   1501 (Ethernet payload)

This packet exceeds the link MTU and is discarded.

If one configures the link MTU on the client side to 1501, one can see the
discarded Ethernet frames with tcpdump running on the client. A

ping -s 2948 -c 1 192.168.15.254

leads to the smaller fragment that is correctly received on the server side:

(tcpdump -vvvne -i eth3 pppoes and ppp proto 0x3d)
52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864),
  length 1514: PPPoE  [ses 0x3] MLPPP (0x003d), length 1494: seq 0x000,
  Flags [end], length 1492

and to the bigger fragment that is not received on the server side:

(tcpdump -vvvne -i eth2 pppoes and ppp proto 0x3d)
52:54:00:70:9e:89 > 52:54:00:5d:6f:b0, ethertype PPPoE S (0x8864),
  length 1515: PPPoE  [ses 0x5] MLPPP (0x003d), length 1495: seq 0x000,
  Flags [begin], length 1493

With the patch below, we correctly obtain three fragments:

52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864),
  length 1514: PPPoE  [ses 0x1] MLPPP (0x003d), length 1494: seq 0x000,
  Flags [begin], length 1492
52:54:00:70:9e:89 > 52:54:00:5d:6f:b0, ethertype PPPoE S (0x8864),
  length 1514: PPPoE  [ses 0x1] MLPPP (0x003d), length 1494: seq 0x000,
  Flags [none], length 1492
52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864),
  length 27: PPPoE  [ses 0x1] MLPPP (0x003d), length 7: seq 0x000,
  Flags [end], length 5

And the ICMPv4 echo request is successfully received at the server side:

IP (tos 0x0, ttl 64, id 21925, offset 0, flags [DF], proto ICMP (1),
  length 2976)
    192.168.222.2 > 192.168.15.254: ICMP echo request, id 30530, seq 0,
      length 2956

The bug was introduced in commit c9aa6895
("[PPPOE]: Advertise PPPoE MTU") from the very beginning. This patch applies
to 3.10 upwards but the fix can be applied (with minor modifications) to
kernels as old as 2.6.32.
Signed-off-by: Christoph Schulz <develop@kristov.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The code in neigh_sysctl_register() relies on a specific layout of
struct neigh_table, namely that the 'gc_*' variables are directly
following the 'parms' member in a specific order. The code, though,
expresses this in the most ugly way.

Get rid of the ugly casts and use the 'tbl' pointer to get a handle to
the table. This way we can refer to the 'gc_*' variables directly.

Similarly seen in the grsecurity patch, written by Brad Spengler.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Brad Spengler <spender@grsecurity.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

While working on some other SCTP code, I noticed that some
structures shared with user space are leaking uninitialized
stack or heap buffer. In particular, struct sctp_sndrcvinfo
has a 2 bytes hole between .sinfo_flags and .sinfo_ppid that
remains unfilled by us in sctp_ulpevent_read_sndrcvinfo() when
putting this into cmsg. But also struct sctp_remote_error
contains a 2 bytes hole that we don't fill but place into a skb
through skb_copy_expand() via sctp_ulpevent_make_remote_error().

Both structures are defined by the IETF in RFC6458:

* Section 5.3.2. SCTP Header Information Structure:

  The sctp_sndrcvinfo structure is defined below:

  struct sctp_sndrcvinfo {
    uint16_t sinfo_stream;
    uint16_t sinfo_ssn;
    uint16_t sinfo_flags;
    <-- 2 bytes hole  -->
    uint32_t sinfo_ppid;
    uint32_t sinfo_context;
    uint32_t sinfo_timetolive;
    uint32_t sinfo_tsn;
    uint32_t sinfo_cumtsn;
    sctp_assoc_t sinfo_assoc_id;
  };

* 6.1.3. SCTP_REMOTE_ERROR:

  A remote peer may send an Operation Error message to its peer.
  This message indicates a variety of error conditions on an
  association. The entire ERROR chunk as it appears on the wire
  is included in an SCTP_REMOTE_ERROR event. Please refer to the
  SCTP specification [RFC4960] and any extensions for a list of
  possible error formats. An SCTP error notification has the
  following format:

  struct sctp_remote_error {
    uint16_t sre_type;
    uint16_t sre_flags;
    uint32_t sre_length;
    uint16_t sre_error;
    <-- 2 bytes hole  -->
    sctp_assoc_t sre_assoc_id;
    uint8_t  sre_data[];
  };

Fix this by setting both to 0 before filling them out. We also
have other structures shared between user and kernel space in
SCTP that contains holes (e.g. struct sctp_paddrthlds), but we
copy that buffer over from user space first and thus don't need
to care about it in that cases.

While at it, we can also remove lengthy comments copied from
the draft, instead, we update the comment with the correct RFC
number where one can look it up.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As of commit f8567a38 it is now possible to
have put_reqs_available() called from irq context.  While put_reqs_available()
is per cpu, it did not protect itself from interrupts on the same CPU.  This
lead to aio_complete() corrupting the available io requests count when run
under a heavy O_DIRECT workloads as reported by Robert Elliott.  Fix this by
disabling irq updates around the per cpu batch updates of reqs_available.

Many thanks to Robert and folks for testing and tracking this down.
Reported-by: Robert Elliot <Elliott@hp.com>
Tested-by: Robert Elliot <Elliott@hp.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@infradead.org>
Cc: stable@vger.kenel.org