If this flag is specified and the target of the rename exists then the
rename syscall fails with EEXIST.

The VFS does the existence checking, so it is trivial to enable for most
local filesystems.  This patch only enables it in ext4.

For network filesystems the VFS check is not enough as there may be a race
between a remote create and the rename, so these filesystems need to handle
this flag in their ->rename() implementations to ensure atomicity.

Andy writes about why this is useful:

"The trivial answer: to eliminate the race condition from 'mv -i'.

Another answer: there's a common pattern to atomically create a file
with contents: open a temporary file, write to it, optionally fsync
it, close it, then link(2) it to the final name, then unlink the
temporary file.

The reason to use link(2) is because it won't silently clobber the destination.

This is annoying:
 - It requires an extra system call that shouldn't be necessary.
 - It doesn't work on (IMO sensible) filesystems that don't support
hard links (e.g. vfat).
 - It's not atomic -- there's an intermediate state where both files exist.
 - It's ugly.

The new rename flag will make this totally sensible.

To be fair, on new enough kernels, you can also use O_TMPFILE and
linkat to achieve the same thing even more cleanly."

Suggested-by: Andy Lutomirski <luto@amacapital.net> 
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Reviewed-by: NJ. Bruce Fields <bfields@redhat.com>

Add new renameat2 syscall, which is the same as renameat with an added
flags argument.

Pass flags to vfs_rename() and to i_op->rename() as well.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Reviewed-by: NJ. Bruce Fields <bfields@redhat.com>

There's actually very little difference between vfs_rename_dir() and
vfs_rename_other() so move both inline into vfs_rename() which still stays
reasonably readable.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Reviewed-by: NJ. Bruce Fields <bfields@redhat.com>

Move the d_move() in vfs_rename_dir() up, similarly to how it's done in
vfs_rename_other().  The next patch will consolidate these two functions
and this is the only structural difference between them.

I'm not sure if doing the d_move() after the dput is even valid.  But there
may be a logical explanation for that.  But moving the d_move() before the
dput() (and the mutex_unlock()) should definitely not hurt.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Reviewed-by: NJ. Bruce Fields <bfields@redhat.com>

Add d_is_dir(dentry) helper which is analogous to S_ISDIR().

To avoid confusion, rename d_is_directory() to d_can_lookup().
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Reviewed-by: NJ. Bruce Fields <bfields@redhat.com>

Pull vfs fixes from Al Viro:
 "Switch mnt_hash to hlist, turning the races between __lookup_mnt() and
  hash modifications into false negatives from __lookup_mnt() (instead
  of hangs)"

On the false negatives from __lookup_mnt():
 "The *only* thing we care about is not getting stuck in __lookup_mnt().
  If it misses an entry because something in front of it just got moved
  around, etc, we are fine.  We'll notice that mount_lock mismatch and
  that'll be it"

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch mnt_hash to hlist
  don't bother with propagate_mnt() unless the target is shared
  keep shadowed vfsmounts together
  resizable namespace.c hashes

I am the new kernel tree Documentation maintainer (except for parts that
are handled by other people, of course).
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NRob Landley <rob@landley.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull input updates from Dmitry Torokhov:
 "Some more updates for the input subsystem.

  You will get a fix for race in mousedev that has been causing quite a
  few oopses lately and a small fixup for force feedback support in
  evdev"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: mousedev - fix race when creating mixed device
  Input: don't modify the id of ioctl-provided ff effect on upload failure

It its possible to configure your PAM stack to refuse login if audit
messages (about the login) were unable to be sent.  This is common in
many distros and thus normal configuration of many containers.  The PAM
modules determine if audit is enabled/disabled in the kernel based on
the return value from sending an audit message on the netlink socket.
If userspace gets back ECONNREFUSED it believes audit is disabled in the
kernel.  If it gets any other error else it refuses to let the login
proceed.

Just about ever since the introduction of namespaces the kernel audit
subsystem has returned EPERM if the task sending a message was not in
the init user or pid namespace.  So many forms of containers have never
worked if audit was enabled in the kernel.

BUT if the container was not in net_init then the kernel network code
would send ECONNREFUSED (instead of the audit code sending EPERM).  Thus
by pure accident/dumb luck/bug if an admin configured the PAM stack to
reject all logins that didn't talk to audit, but then ran the login
untility in the non-init_net namespace, it would work!! Clearly this was
a bug, but it is a bug some people expected.

With the introduction of network namespace support in 3.14-rc1 the two
bugs stopped cancelling each other out.  Now, containers in the
non-init_net namespace refused to let users log in (just like PAM was
configfured!) Obviously some people were not happy that what used to let
users log in, now didn't!

This fix is kinda hacky.  We return ECONNREFUSED for all non-init
relevant namespaces.  That means that not only will the old broken
non-init_net setups continue to work, now the broken non-init_pid or
non-init_user setups will 'work'.  They don't really work, since audit
isn't logging things.  But it's what most users want.

In 3.15 we should have patches to support not only the non-init_net
(3.14) namespace but also the non-init_pid and non-init_user namespace.
So all will be right in the world.  This just opens the doors wide open
on 3.14 and hopefully makes users happy, if not the audit system...
Reported-by: NAndre Tomt <andre@tomt.net>
Reported-by: NAdam Richter <adam_richter2004@yahoo.com>
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use cmpxchg() to atomically set i_flags instead of clearing out the
S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race
where an immutable file has the immutable flag cleared for a brief
window of time.
Reported-by: NJohn Sullivan <jsrhbz@kanargh.force9.co.uk>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fixes RCU bug - walking through hlist is safe in face of element moves,
since it's self-terminating.  Cyclic lists are not - if we end up jumping
to another hash chain, we'll loop infinitely without ever hitting the
original list head.

[fix for dumb braino folded]

Spotted by: Max Kellermann <mk@cm4all.com>
Cc: stable@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If the dest_mnt is not shared, propagate_mnt() does nothing -
there's no mounts to propagate to and thus no copies to create.
Might as well don't bother calling it in that case.

Cc: stable@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

preparation to switching mnt_hash to hlist

Cc: stable@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* switch allocation to alloc_large_system_hash()
* make sizes overridable by boot parameters (mhash_entries=, mphash_entries=)
* switch mountpoint_hashtable from list_head to hlist_head

Cc: stable@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Pull timer fix from Ingo Molnar:
 "A late breaking fix from John.  (The bug fixed has a hard lockup
  potential, but that was not observed, warnings were)"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Revert to calling clock_was_set_delayed() while in irq context

Pull Ceph fix from Sage Weil:
 "This drops a bad assert that a few users have been hitting but we've
  only recently been able to track down"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: drop an unsafe assertion

We should not be using static variable mousedev_mix in methods that can be
called before that singleton gets assigned. While at it let's add open and
close methods to mousedev structure so that we do not need to test if we
are dealing with multiplexor or normal device and simply call appropriate
method directly.

This fixes: https://bugzilla.kernel.org/show_bug.cgi?id=71551Reported-by: NGiulioDP <depasquale.giulio@gmail.com>
Tested-by: NGiulioDP <depasquale.giulio@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

If a new (id == -1) ff effect was uploaded from userspace,
ff-core.c::input_ff_upload() will have assigned a positive number to the
new effect id.  Currently, evdev.c::evdev_do_ioctl() will save this new id
to userspace, regardless of whether the upload succeeded or not.

On upload failure, this can be confusing because the dev->ff->effects[]
array will not contain an element at the index of that new effect id.

This patch fixes this by leaving the id unchanged after upload fails.

Note: Unfortunately applications should still expect changed effect id for
quite some time.

This has been discussed on:
http://www.mail-archive.com/linux-input@vger.kernel.org/msg08513.html
("ff-core effect id handling in case of a failed effect upload")
Suggested-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NElias Vanderstuyft <elias.vds@gmail.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Olivier Bonvalet reported having repeated crashes due to a failed
assertion he was hitting in rbd_img_obj_callback():

    Assertion failure in rbd_img_obj_callback() at line 2165:
	rbd_assert(which >= img_request->next_completion);

With a lot of help from Olivier with reproducing the problem
we were able to determine the object and image requests had
already been completed (and often freed) at the point the
assertion failed.

There was a great deal of discussion on the ceph-devel mailing list
about this.  The problem only arose when there were two (or more)
object requests in an image request, and the problem was always
seen when the second request was being completed.

The problem is due to a race in the window between setting the
"done" flag on an object request and checking the image request's
next completion value.  When the first object request completes, it
checks to see if its successor request is marked "done", and if
so, that request is also completed.  In the process, the image
request's next_completion value is updated to reflect that both
the first and second requests are completed.  By the time the
second request is able to check the next_completion value, it
has been set to a value *greater* than its own "which" value,
which caused an assertion to fail.

Fix this problem by skipping over any completion processing
unless the completing object request is the next one expected.
Test only for inequality (not >=), and eliminate the bad
assertion.
Tested-by: NOlivier Bonvalet <ob@daevel.fr>
Signed-off-by: NAlex Elder <elder@linaro.org>
Reviewed-by: NSage Weil <sage@inktank.com>
Reviewed-by: NIlya Dryomov <ilya.dryomov@inktank.com>

Pull networking fixes from David Miller:

 1) We've discovered a common error in several networking drivers, they
    put VLAN offload features into ->vlan_features, which would suggest
    that they support offloading 2 or more levels of VLAN encapsulation.
    Not only do these devices not do that, but we don't have the
    infrastructure yet to handle that at all.

    Fixes from Vlad Yasevich.

 2) Fix tcpdump crash with bridging and vlans, also from Vlad.

 3) Some MAINTAINERS updates for random32 and bonding.

 4) Fix late reseeds of prandom generator, from Sasha Levin.

 5) Bridge doesn't handle stacked vlans properly, fix from Toshiaki
    Makita.

 6) Fix deadlock in openvswitch, from Flavio Leitner.

 7) get_timewait4_sock() doesn't report delay times correctly, fix from
    Eric Dumazet.

 8) Duplicate address detection and addrconf verification need to run in
    contexts where RTNL can be obtained.  Move them to run from a
    workqueue.  From Hannes Frederic Sowa.

 9) Fix route refcount leaking in ip tunnels, from Pravin B Shelar.

10) Don't return -EINTR from non-blocking recvmsg() on AF_UNIX sockets,
    from Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (28 commits)
  vlan: Warn the user if lowerdev has bad vlan features.
  veth: Turn off vlan rx acceleration in vlan_features
  ifb: Remove vlan acceleration from vlan_features
  qlge: Do not propaged vlan tag offloads to vlans
  bridge: Fix crash with vlan filtering and tcpdump
  net: Account for all vlan headers in skb_mac_gso_segment
  MAINTAINERS: bonding: change email address
  MAINTAINERS: bonding: change email address
  ipv6: move DAD and addrconf_verify processing to workqueue
  tcp: fix get_timewait4_sock() delay computation on 64bit
  openvswitch: fix a possible deadlock and lockdep warning
  bridge: Fix handling stacked vlan tags
  bridge: Fix inabillity to retrieve vlan tags when tx offload is disabled
  vhost: validate vhost_get_vq_desc return value
  vhost: fix total length when packets are too short
  random32: avoid attempt to late reseed if in the middle of seeding
  random32: assign to network folks in MAINTAINERS
  net/mlx4_core: pass pci_device_id.driver_data to __mlx4_init_one during reset
  core, nfqueue, openvswitch: Orphan frags in skb_zerocopy and handle errors
  vlan: Set hard_header_len according to available acceleration
  ...

Vlad Yasevich says:

====================
Audit all drivers for correct vlan_features.

Some drivers set vlan acceleration features in vlan_features.  This causes
issues with Q-in-Q/802.1ad configurations.

Audit all the drivers for correct vlan_features.  Fix broken ones.
Add a warning to vlan code to help catch future offenders.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some drivers incorrectly assign vlan acceleration features to
vlan_features thus causing issues for Q-in-Q vlan configurations.
Warn the user of such cases.
Signed-off-by: NVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For completeness, turn off vlan rx acceleration in vlan_features so
that it doesn't show up on q-in-q setups.
Signed-off-by: NVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Do not include vlan acceleration features in vlan_features as that
precludes correct Q-in-Q operation.
Signed-off-by: NVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qlge driver turns off NETIF_F_HW_CTAG_FILTER, but forgets to
turn off HW_CTAG_TX and HW_CTAG_RX on vlan devices.  With the
current settings, q-in-q will only generate a single vlan header.
Remember to mask off CTAG_TX and CTAG_RX features in vlan_features.

CC: Shahed Shaikh <shahed.shaikh@qlogic.com>
CC: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
CC: Ron Mercer <ron.mercer@qlogic.com>
Signed-off-by: NVlad Yasevich <vyasevic@redhat.com>
Acked-by: NJitendra Kalsaria <jitendra.kalsaria@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the vlan filtering is enabled on the bridge, but
the filter is not configured on the bridge device itself,
running tcpdump on the bridge device will result in a
an Oops with NULL pointer dereference.  The reason
is that br_pass_frame_up() will bypass the vlan
check because promisc flag is set.  It will then try
to get the table pointer and process the packet based
on the table.  Since the table pointer is NULL, we oops.
Catch this special condition in br_handle_vlan().
Reported-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
CC: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: NVlad Yasevich <vyasevic@redhat.com>
Acked-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

skb_network_protocol() already accounts for multiple vlan
headers that may be present in the skb.  However, skb_mac_gso_segment()
doesn't know anything about it and assumes that skb->mac_len
is set correctly to skip all mac headers.  That may not
always be the case.  If we are simply forwarding the packet (via
bridge or macvtap), all vlan headers may not be accounted for.

A simple solution is to allow skb_network_protocol to return
the vlan depth it has calculated.  This way skb_mac_gso_segment
will correctly skip all mac headers.
Signed-off-by: NVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Update my email address.
Signed-off-by: NJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Merge two fixes from Andrew Morton:
 "The x86 fix should come from x86 guys but they appear to be
  conferencing or otherwise distracted.

  The ocfs2 fix is a bit of a mess - the code runs into an immediate
  NULL deref and we're trying to work out how this got through test and
  review, but we haven't heard from Goldwyn in the past few days.
  Sasha's patch fixes the oops, but the feature as a whole is probably
  broken.  So this is a stopgap for 3.14 - I'll aim to get the real
  fixes into 3.14.x"

* emailed patches from Andrew Morton akpm@linux-foundation.org>:
  x86: fix boot on uniprocessor systems
  ocfs2: check if cluster name exists before deref

On x86 uniprocessor systems topology_physical_package_id() returns -1
which causes rapl_cpu_prepare() to leave rapl_pmu variable uninitialized
which leads to GPF in rapl_pmu_init().

See arch/x86/kernel/cpu/perf_event_intel_rapl.c.

It turns out that physical_package_id and core_id can actually be
retreived for uniprocessor systems too.  Enabling them also fixes
rapl_pmu code.
Signed-off-by: NArtem Fetishev <artem_fetishev@epam.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit c74a3bdd ("ocfs2: add clustername to cluster connection") is
trying to strlcpy a string which was explicitly passed as NULL in the
very same patch, triggering a NULL ptr deref.

  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: strlcpy (lib/string.c:388 lib/string.c:151)
  CPU: 19 PID: 19426 Comm: trinity-c19 Tainted: G        W     3.14.0-rc7-next-20140325-sasha-00014-g9476368-dirty #274
  RIP:  strlcpy (lib/string.c:388 lib/string.c:151)
  Call Trace:
   ocfs2_cluster_connect (fs/ocfs2/stackglue.c:350)
   ocfs2_cluster_connect_agnostic (fs/ocfs2/stackglue.c:396)
   user_dlm_register (fs/ocfs2/dlmfs/userdlm.c:679)
   dlmfs_mkdir (fs/ocfs2/dlmfs/dlmfs.c:503)
   vfs_mkdir (fs/namei.c:3467)
   SyS_mkdirat (fs/namei.c:3488 fs/namei.c:3472)
   tracesys (arch/x86/kernel/entry_64.S:749)

akpm: this patch probably disables the feature.  A temporary thing to
avoid triviel oopses.
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

addrconf_join_solict and addrconf_join_anycast may cause actions which
need rtnl locked, especially on first address creation.

A new DAD state is introduced which defers processing of the initial
DAD processing into a workqueue.

To get rtnl lock we need to push the code paths which depend on those
calls up to workqueues, specifically addrconf_verify and the DAD
processing.

(v2)
addrconf_dad_failure needs to be queued up to the workqueue, too. This
patch introduces a new DAD state and stop the DAD processing in the
workqueue (this is because of the possible ipv6_del_addr processing
which removes the solicited multicast address from the device).

addrconf_verify_lock is removed, too. After the transition it is not
needed any more.

As we are not processing in bottom half anymore we need to be a bit more
careful about disabling bottom half out when we lock spin_locks which are also
used in bh.

Relevant backtrace:
[  541.030090] RTNL: assertion failed at net/core/dev.c (4496)
[  541.031143] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G           O 3.10.33-1-amd64-vyatta #1
[  541.031145] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[  541.031146]  ffffffff8148a9f0 000000000000002f ffffffff813c98c1 ffff88007c4451f8
[  541.031148]  0000000000000000 0000000000000000 ffffffff813d3540 ffff88007fc03d18
[  541.031150]  0000880000000006 ffff88007c445000 ffffffffa0194160 0000000000000000
[  541.031152] Call Trace:
[  541.031153]  <IRQ>  [<ffffffff8148a9f0>] ? dump_stack+0xd/0x17
[  541.031180]  [<ffffffff813c98c1>] ? __dev_set_promiscuity+0x101/0x180
[  541.031183]  [<ffffffff813d3540>] ? __hw_addr_create_ex+0x60/0xc0
[  541.031185]  [<ffffffff813cfe1a>] ? __dev_set_rx_mode+0xaa/0xc0
[  541.031189]  [<ffffffff813d3a81>] ? __dev_mc_add+0x61/0x90
[  541.031198]  [<ffffffffa01dcf9c>] ? igmp6_group_added+0xfc/0x1a0 [ipv6]
[  541.031208]  [<ffffffff8111237b>] ? kmem_cache_alloc+0xcb/0xd0
[  541.031212]  [<ffffffffa01ddcd7>] ? ipv6_dev_mc_inc+0x267/0x300 [ipv6]
[  541.031216]  [<ffffffffa01c2fae>] ? addrconf_join_solict+0x2e/0x40 [ipv6]
[  541.031219]  [<ffffffffa01ba2e9>] ? ipv6_dev_ac_inc+0x159/0x1f0 [ipv6]
[  541.031223]  [<ffffffffa01c0772>] ? addrconf_join_anycast+0x92/0xa0 [ipv6]
[  541.031226]  [<ffffffffa01c311e>] ? __ipv6_ifa_notify+0x11e/0x1e0 [ipv6]
[  541.031229]  [<ffffffffa01c3213>] ? ipv6_ifa_notify+0x33/0x50 [ipv6]
[  541.031233]  [<ffffffffa01c36c8>] ? addrconf_dad_completed+0x28/0x100 [ipv6]
[  541.031241]  [<ffffffff81075c1d>] ? task_cputime+0x2d/0x50
[  541.031244]  [<ffffffffa01c38d6>] ? addrconf_dad_timer+0x136/0x150 [ipv6]
[  541.031247]  [<ffffffffa01c37a0>] ? addrconf_dad_completed+0x100/0x100 [ipv6]
[  541.031255]  [<ffffffff8105313a>] ? call_timer_fn.isra.22+0x2a/0x90
[  541.031258]  [<ffffffffa01c37a0>] ? addrconf_dad_completed+0x100/0x100 [ipv6]

Hunks and backtrace stolen from a patch by Stephen Hemminger.
Reported-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It seems I missed one change in get_timewait4_sock() to compute
the remaining time before deletion of IPV4 timewait socket.

This could result in wrong output in /proc/net/tcp for tm->when field.

Fixes: 96f817fe ("tcp: shrink tcp6_timewait_sock by one cache line")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are two problematic situations.

A deadlock can happen when is_percpu is false because it can get
interrupted while holding the spinlock. Then it executes
ovs_flow_stats_update() in softirq context which tries to get
the same lock.

The second sitation is that when is_percpu is true, the code
correctly disables BH but only for the local CPU, so the
following can happen when locking the remote CPU without
disabling BH:

       CPU#0                            CPU#1
  ovs_flow_stats_get()
   stats_read()
 +->spin_lock remote CPU#1        ovs_flow_stats_get()
 |  <interrupted>                  stats_read()
 |  ...                       +-->  spin_lock remote CPU#0
 |                            |     <interrupted>
 |  ovs_flow_stats_update()   |     ...
 |   spin_lock local CPU#0 <--+     ovs_flow_stats_update()
 +---------------------------------- spin_lock local CPU#1

This patch disables BH for both cases fixing the deadlocks.
Acked-by: NJesse Gross <jesse@nicira.com>

=================================
[ INFO: inconsistent lock state ]
3.14.0-rc8-00007-g632b06aa #1 Tainted: G          I
---------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
swapper/0/0 [HC0[0]:SC1[5]:HE1:SE0] takes:
(&(&cpu_stats->lock)->rlock){+.?...}, at: [<ffffffffa05dd8a1>] ovs_flow_stats_update+0x51/0xd0 [openvswitch]
{SOFTIRQ-ON-W} state was registered at:
[<ffffffff810f973f>] __lock_acquire+0x68f/0x1c40
[<ffffffff810fb4e2>] lock_acquire+0xa2/0x1d0
[<ffffffff817d8d9e>] _raw_spin_lock+0x3e/0x80
[<ffffffffa05dd9e4>] ovs_flow_stats_get+0xc4/0x1e0 [openvswitch]
[<ffffffffa05da855>] ovs_flow_cmd_fill_info+0x185/0x360 [openvswitch]
[<ffffffffa05daf05>] ovs_flow_cmd_build_info.constprop.27+0x55/0x90 [openvswitch]
[<ffffffffa05db41d>] ovs_flow_cmd_new_or_set+0x4dd/0x570 [openvswitch]
[<ffffffff816c245d>] genl_family_rcv_msg+0x1cd/0x3f0
[<ffffffff816c270e>] genl_rcv_msg+0x8e/0xd0
[<ffffffff816c0239>] netlink_rcv_skb+0xa9/0xc0
[<ffffffff816c0798>] genl_rcv+0x28/0x40
[<ffffffff816bf830>] netlink_unicast+0x100/0x1e0
[<ffffffff816bfc57>] netlink_sendmsg+0x347/0x770
[<ffffffff81668e9c>] sock_sendmsg+0x9c/0xe0
[<ffffffff816692d9>] ___sys_sendmsg+0x3a9/0x3c0
[<ffffffff8166a911>] __sys_sendmsg+0x51/0x90
[<ffffffff8166a962>] SyS_sendmsg+0x12/0x20
[<ffffffff817e3ce9>] system_call_fastpath+0x16/0x1b
irq event stamp: 1740726
hardirqs last  enabled at (1740726): [<ffffffff8175d5e0>] ip6_finish_output2+0x4f0/0x840
hardirqs last disabled at (1740725): [<ffffffff8175d59b>] ip6_finish_output2+0x4ab/0x840
softirqs last  enabled at (1740674): [<ffffffff8109be12>] _local_bh_enable+0x22/0x50
softirqs last disabled at (1740675): [<ffffffff8109db05>] irq_exit+0xc5/0xd0

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&cpu_stats->lock)->rlock);
  <Interrupt>
    lock(&(&cpu_stats->lock)->rlock);

 *** DEADLOCK ***

5 locks held by swapper/0/0:
 #0:  (((&ifa->dad_timer))){+.-...}, at: [<ffffffff810a7155>] call_timer_fn+0x5/0x320
 #1:  (rcu_read_lock){.+.+..}, at: [<ffffffff81788a55>] mld_sendpack+0x5/0x4a0
 #2:  (rcu_read_lock_bh){.+....}, at: [<ffffffff8175d149>] ip6_finish_output2+0x59/0x840
 #3:  (rcu_read_lock_bh){.+....}, at: [<ffffffff8168ba75>] __dev_queue_xmit+0x5/0x9b0
 #4:  (rcu_read_lock){.+.+..}, at: [<ffffffffa05e41b5>] internal_dev_xmit+0x5/0x110 [openvswitch]

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G          I  3.14.0-rc8-00007-g632b06aa #1
Hardware name:                  /DX58SO, BIOS SOX5810J.86A.5599.2012.0529.2218 05/29/2012
 0000000000000000 0fcf20709903df0c ffff88042d603808 ffffffff817cfe3c
 ffffffff81c134c0 ffff88042d603858 ffffffff817cb6da 0000000000000005
 ffffffff00000001 ffff880400000000 0000000000000006 ffffffff81c134c0
Call Trace:
 <IRQ>  [<ffffffff817cfe3c>] dump_stack+0x4d/0x66
 [<ffffffff817cb6da>] print_usage_bug+0x1f4/0x205
 [<ffffffff810f7f10>] ? check_usage_backwards+0x180/0x180
 [<ffffffff810f8963>] mark_lock+0x223/0x2b0
 [<ffffffff810f96d3>] __lock_acquire+0x623/0x1c40
 [<ffffffff810f5707>] ? __lock_is_held+0x57/0x80
 [<ffffffffa05e26c6>] ? masked_flow_lookup+0x236/0x250 [openvswitch]
 [<ffffffff810fb4e2>] lock_acquire+0xa2/0x1d0
 [<ffffffffa05dd8a1>] ? ovs_flow_stats_update+0x51/0xd0 [openvswitch]
 [<ffffffff817d8d9e>] _raw_spin_lock+0x3e/0x80
 [<ffffffffa05dd8a1>] ? ovs_flow_stats_update+0x51/0xd0 [openvswitch]
 [<ffffffffa05dd8a1>] ovs_flow_stats_update+0x51/0xd0 [openvswitch]
 [<ffffffffa05dcc64>] ovs_dp_process_received_packet+0x84/0x120 [openvswitch]
 [<ffffffff810f93f7>] ? __lock_acquire+0x347/0x1c40
 [<ffffffffa05e3bea>] ovs_vport_receive+0x2a/0x30 [openvswitch]
 [<ffffffffa05e4218>] internal_dev_xmit+0x68/0x110 [openvswitch]
 [<ffffffffa05e41b5>] ? internal_dev_xmit+0x5/0x110 [openvswitch]
 [<ffffffff8168b4a6>] dev_hard_start_xmit+0x2e6/0x8b0
 [<ffffffff8168be87>] __dev_queue_xmit+0x417/0x9b0
 [<ffffffff8168ba75>] ? __dev_queue_xmit+0x5/0x9b0
 [<ffffffff8175d5e0>] ? ip6_finish_output2+0x4f0/0x840
 [<ffffffff8168c430>] dev_queue_xmit+0x10/0x20
 [<ffffffff8175d641>] ip6_finish_output2+0x551/0x840
 [<ffffffff8176128a>] ? ip6_finish_output+0x9a/0x220
 [<ffffffff8176128a>] ip6_finish_output+0x9a/0x220
 [<ffffffff8176145f>] ip6_output+0x4f/0x1f0
 [<ffffffff81788c29>] mld_sendpack+0x1d9/0x4a0
 [<ffffffff817895b8>] mld_send_initial_cr.part.32+0x88/0xa0
 [<ffffffff817691b0>] ? addrconf_dad_completed+0x220/0x220
 [<ffffffff8178e301>] ipv6_mc_dad_complete+0x31/0x50
 [<ffffffff817690d7>] addrconf_dad_completed+0x147/0x220
 [<ffffffff817691b0>] ? addrconf_dad_completed+0x220/0x220
 [<ffffffff8176934f>] addrconf_dad_timer+0x19f/0x1c0
 [<ffffffff810a71e9>] call_timer_fn+0x99/0x320
 [<ffffffff810a7155>] ? call_timer_fn+0x5/0x320
 [<ffffffff817691b0>] ? addrconf_dad_completed+0x220/0x220
 [<ffffffff810a76c4>] run_timer_softirq+0x254/0x3b0
 [<ffffffff8109d47d>] __do_softirq+0x12d/0x480
Signed-off-by: NFlavio Leitner <fbl@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a bridge with vlan_filtering enabled receives frames with stacked
vlan tags, i.e., they have two vlan tags, br_vlan_untag() strips not
only the outer tag but also the inner tag.

br_vlan_untag() is called only from br_handle_vlan(), and in this case,
it is enough to set skb->vlan_tci to 0 here, because vlan_tci has already
been set before calling br_handle_vlan().
Signed-off-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: NVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bridge vlan code (br_vlan_get_tag()) assumes that all frames have vlan_tci
if they are tagged, but if vlan tx offload is manually disabled on bridge
device and frames are sent from vlan device on the bridge device, the tags
are embedded in skb->data and they break this assumption.
Extract embedded vlan tags and move them to vlan_tci at ingress.
Signed-off-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: NVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

vhost fails to validate negative error code
from vhost_get_vq_desc causing
a crash: we are using -EFAULT which is 0xfffffff2
as vector size, which exceeds the allocated size.

The code in question was introduced in commit
8dd014ad
    vhost-net: mergeable buffers support

CVE-2014-0055
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When mergeable buffers are disabled, and the
incoming packet is too large for the rx buffer,
get_rx_bufs returns success.

This was intentional in order for make recvmsg
truncate the packet and then handle_rx would
detect err != sock_len and drop it.

Unfortunately we pass the original sock_len to
recvmsg - which means we use parts of iov not fully
validated.

Fix this up by detecting this overrun and doing packet drop
immediately.

CVE-2014-0077
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>