ext4: atomically set inode->i_flags in ext4_set_inode_flags()

commit 00a1a053ebe5febcfc2ec498bd894f035ad2aa06 upstream.

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: John Sullivan <jsrhbz@kanargh.force9.co.uk>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Input: mousedev - fix race when creating mixed device

commit e4dbedc7eac7da9db363a36f2bd4366962eeefcc upstream.

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=71551

Reported-by: GiulioDP <depasquale.giulio@gmail.com>
Tested-by: GiulioDP <depasquale.giulio@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Input: synaptics - add manual min/max quirk

commit 421e08c41fda1f0c2ff6af81a67b491389b653a5 upstream.

The new Lenovo Haswell series (-40's) contains a new Synaptics touchpad.
However, these new Synaptics devices report bad axis ranges.
Under Windows, it is not a problem because the Windows driver uses RMI4
over SMBus to talk to the device. Under Linux, we are using the PS/2
fallback interface and it occurs the reported ranges are wrong.

Of course, it would be too easy to have only one range for the whole
series, each touchpad seems to be calibrated in a different way.

We can not use SMBus to get the actual range because I suspect the firmware
will switch into the SMBus mode and stop talking through PS/2 (this is the
case for hybrid HID over I2C / PS/2 Synaptics touchpads).

So as a temporary solution (until RMI4 land into upstream), start a new
list of quirks with the min/max manually set.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Input: synaptics - add manual min/max quirk for ThinkPad X240

commit 8a0435d958fb36d93b8df610124a0e91e5675c82 upstream.

This extends Benjamin Tissoires manual min/max quirk table with support for
the ThinkPad X240.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Input: cypress_ps2 - don't report as a button pads

commit 6797b39e6f6f34c74177736e146406e894b9482b upstream.

The cypress PS/2 trackpad models supported by the cypress_ps2 driver
emulate BTN_RIGHT events in firmware based on the finger position, as part
of this no motion events are sent when the finger is in the button area.

The INPUT_PROP_BUTTONPAD property is there to indicate to userspace that
BTN_RIGHT events should be emulated in userspace, which is not necessary
in this case.

When INPUT_PROP_BUTTONPAD is advertised userspace will wait for a motion
event before propagating the button event higher up the stack, as it needs
current abs x + y data for its BTN_RIGHT emulation. Since in the
cypress_ps2 pads don't report motion events in the button area, this means
that clicks in the button area end up being ignored, so
INPUT_PROP_BUTTONPAD actually causes problems for these touchpads, and
removing it fixes:

https://bugs.freedesktop.org/show_bug.cgi?id=76341

Reported-by: Adam Williamson <awilliam@redhat.com>
Tested-by: Adam Williamson <awilliam@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86: fix boot on uniprocessor systems

commit 825600c0f20e595daaa7a6dd8970f84fa2a2ee57 upstream.

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: Artem 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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: mvneta: rename MVNETA_GMAC2_PSC_ENABLE to MVNETA_GMAC2_PCS_ENABLE

commit a79121d3b57e7ad61f0b5d23eae05214054f3ccd upstream.

Bit 3 of the MVNETA_GMAC_CTRL_2 is actually used to enable the PCS,
not the PSC: there was a typo in the name of the define, which this
commit fixes.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm: close PageTail race

commit 668f9abbd4334e6c29fa8acd71635c4f9101caa7 upstream.

Commit bf6bddf1924e ("mm: introduce compaction and migration for
ballooned pages") introduces page_count(page) into memory compaction
which dereferences page->first_page if PageTail(page).

This results in a very rare NULL pointer dereference on the
aforementioned page_count(page).  Indeed, anything that does
compound_head(), including page_count() is susceptible to racing with
prep_compound_page() and seeing a NULL or dangling page->first_page
pointer.

This patch uses Andrea's implementation of compound_trans_head() that
deals with such a race and makes it the default compound_head()
implementation.  This includes a read memory barrier that ensures that
if PageTail(head) is true that we return a head page that is neither
NULL nor dangling.  The patch then adds a store memory barrier to
prep_compound_page() to ensure page->first_page is set.

This is the safest way to ensure we see the head page that we are
expecting, PageTail(page) is already in the unlikely() path and the
memory barriers are unfortunately required.

Hugetlbfs is the exception, we don't enforce a store memory barrier
during init since no race is possible.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Holger Kiehl <Holger.Kiehl@dwd.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: nf_conntrack_dccp: fix skb_header_pointer API usages

commit b22f5126a24b3b2f15448c3f2a254fc10cbc2b92 upstream.

Some occurences in the netfilter tree use skb_header_pointer() in
the following way ...

  struct dccp_hdr _dh, *dh;
  ...
  skb_header_pointer(skb, dataoff, sizeof(_dh), &dh);

... where dh itself is a pointer that is being passed as the copy
buffer. Instead, we need to use &_dh as the forth argument so that
we're copying the data into an actual buffer that sits on the stack.

Currently, we probably could overwrite memory on the stack (e.g.
with a possibly mal-formed DCCP packet), but unintentionally, as
we only want the buffer to be placed into _dh variable.

Fixes: 2bc780499aa3 ("[NETFILTER]: nf_conntrack: add DCCP protocol support")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux 3.10.36
selinux: correctly label /proc inodes in use before the policy is loaded

commit f64410ec665479d7b4b77b7519e814253ed0f686 upstream.

This patch is based on an earlier patch by Eric Paris, he describes
the problem below:

  "If an inode is accessed before policy load it will get placed on a
   list of inodes to be initialized after policy load.  After policy
   load we call inode_doinit() which calls inode_doinit_with_dentry()
   on all inodes accessed before policy load.  In the case of inodes
   in procfs that means we'll end up at the bottom where it does:

     /* Default to the fs superblock SID. */
     isec->sid = sbsec->sid;

     if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
             if (opt_dentry) {
                     isec->sclass = inode_mode_to_security_class(...)
                     rc = selinux_proc_get_sid(opt_dentry,
                                               isec->sclass,
                                               &sid);
                     if (rc)
                             goto out_unlock;
                     isec->sid = sid;
             }
     }

   Since opt_dentry is null, we'll never call selinux_proc_get_sid()
   and will leave the inode labeled with the label on the superblock.
   I believe a fix would be to mimic the behavior of xattrs.  Look
   for an alias of the inode.  If it can't be found, just leave the
   inode uninitialized (and pick it up later) if it can be found, we
   should be able to call selinux_proc_get_sid() ..."

On a system exhibiting this problem, you will notice a lot of files in
/proc with the generic "proc_t" type (at least the ones that were
accessed early in the boot), for example:

   # ls -Z /proc/sys/kernel/shmmax | awk '{ print $4 " " $5 }'
   system_u:object_r:proc_t:s0 /proc/sys/kernel/shmmax

However, with this patch in place we see the expected result:

   # ls -Z /proc/sys/kernel/shmmax | awk '{ print $4 " " $5 }'
   system_u:object_r:sysctl_kernel_t:s0 /proc/sys/kernel/shmmax

Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powernow-k6: disable cache when changing frequency

commit e20e1d0ac02308e2211306fc67abcd0b2668fb8b upstream.

I found out that a system with k6-3+ processor is unstable during network
server load. The system locks up or the network card stops receiving. The
reason for the instability is the CPU frequency scaling.

During frequency transition the processor is in "EPM Stop Grant" state.
The documentation says that the processor doesn't respond to inquiry
requests in this state. Consequently, coherency of processor caches and
bus master devices is not maintained, causing the system instability.

This patch flushes the cache during frequency transition. It fixes the
instability.

Other minor changes:
* u64 invalue changed to unsigned long because the variable is 32-bit
* move the logic to set the multiplier to a separate function
  powernow_k6_set_cpu_multiplier
* preserve lower 5 bits of the powernow port instead of 4 (the voltage
  field has 5 bits)
* mask interrupts when reading the multiplier, so that the port is not
  open during other activity (running other kernel code with the port open
  shouldn't cause any misbehavior, but we should better be safe and keep
  the port closed)

This patch should be backported to all stable kernels. If it doesn't
apply cleanly, change it, or ask me to change it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powernow-k6: correctly initialize default parameters

commit d82b922a4acc1781d368aceac2f9da43b038cab2 upstream.

The powernow-k6 driver used to read the initial multiplier from the
powernow register. However, there is a problem with this:

* If there was a frequency transition before, the multiplier read from the
  register corresponds to the current multiplier.
* If there was no frequency transition since reset, the field in the
  register always reads as zero, regardless of the current multiplier that
  is set using switches on the mainboard and that the CPU is running at.

The zero value corresponds to multiplier 4.5, so as a consequence, the
powernow-k6 driver always assumes multiplier 4.5.

For example, if we have 550MHz CPU with bus frequency 100MHz and
multiplier 5.5, the powernow-k6 driver thinks that the multiplier is 4.5
and bus frequency is 122MHz. The powernow-k6 driver then sets the
multiplier to 4.5, underclocking the CPU to 450MHz, but reports the
current frequency as 550MHz.

There is no reliable way how to read the initial multiplier. I modified
the driver so that it contains a table of known frequencies (based on
parameters of existing CPUs and some common overclocking schemes) and sets
the multiplier according to the frequency. If the frequency is unknown
(because of unusual overclocking or underclocking), the user must supply
the bus speed and maximum multiplier as module parameters.

This patch should be backported to all stable kernels. If it doesn't
apply cleanly, change it, or ask me to change it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powernow-k6: reorder frequencies

commit 22c73795b101597051924556dce019385a1e2fa0 upstream.

This patch reorders reported frequencies from the highest to the lowest,
just like in other frequency drivers.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kbuild: fix make headers_install when path is too long

commit c0ff68f1611d6855a06d672989ad5cfea160a4eb upstream.

If headers_install is executed from a deep/long directory structure, the
shell's maximum argument length can be execeeded, which breaks the operation
with:

| make[2]: execvp: /bin/sh: Argument list too long
| make[2]: ***

Instead of passing each files name with the entire path, I give only the file
name without the source path and give this path as a new argument to
headers_install.pl.

Because there is three possible paths, I have tree input-files list, one per
path.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Tested-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Cc: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpuidle: Check the result of cpuidle_get_driver() against NULL

commit 3b9c10e98021e1f92e6f8c7ce1778b86ba68db10 upstream.

If the current CPU has no cpuidle driver, drv will be NULL in
cpuidle_driver_ref().  Check if that is the case before trying
to bump up the driver's refcount to prevent the kernel from
crashing.

[rjw: Subject and changelog]
Signed-off-by: Daniel Fu <danifu@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: fix for a race condition in the inet frag code

[ Upstream commit 24b9bf43e93e0edd89072da51cf1fab95fc69dec ]

I stumbled upon this very serious bug while hunting for another one,
it's a very subtle race condition between inet_frag_evictor,
inet_frag_intern and the IPv4/6 frag_queue and expire functions
(basically the users of inet_frag_kill/inet_frag_put).

What happens is that after a fragment has been added to the hash chain
but before it's been added to the lru_list (inet_frag_lru_add) in
inet_frag_intern, it may get deleted (either by an expired timer if
the system load is high or the timer sufficiently low, or by the
fraq_queue function for different reasons) before it's added to the
lru_list, then after it gets added it's a matter of time for the
evictor to get to a piece of memory which has been freed leading to a
number of different bugs depending on what's left there.

I've been able to trigger this on both IPv4 and IPv6 (which is normal
as the frag code is the same), but it's been much more difficult to
trigger on IPv4 due to the protocol differences about how fragments
are treated.

The setup I used to reproduce this is: 2 machines with 4 x 10G bonded
in a RR bond, so the same flow can be seen on multiple cards at the
same time. Then I used multiple instances of ping/ping6 to generate
fragmented packets and flood the machines with them while running
other processes to load the attacked machine.

*It is very important to have the _same flow_ coming in on multiple CPUs
concurrently. Usually the attacked machine would die in less than 30
minutes, if configured properly to have many evictor calls and timeouts
it could happen in 10 minutes or so.

An important point to make is that any caller (frag_queue or timer) of
inet_frag_kill will remove both the timer refcount and the
original/guarding refcount thus removing everything that's keeping the
frag from being freed at the next inet_frag_put.  All of this could
happen before the frag was ever added to the LRU list, then it gets
added and the evictor uses a freed fragment.

An example for IPv6 would be if a fragment is being added and is at
the stage of being inserted in the hash after the hash lock is
released, but before inet_frag_lru_add executes (or is able to obtain
the lru lock) another overlapping fragment for the same flow arrives
at a different CPU which finds it in the hash, but since it's
overlapping it drops it invoking inet_frag_kill and thus removing all
guarding refcounts, and afterwards freeing it by invoking
inet_frag_put which removes the last refcount added previously by
inet_frag_find, then inet_frag_lru_add gets executed by
inet_frag_intern and we have a freed fragment in the lru_list.

The fix is simple, just move the lru_add under the hash chain locked
region so when a removing function is called it'll have to wait for
the fragment to be added to the lru_list, and then it'll remove it (it
works because the hash chain removal is done before the lru_list one
and there's no window between the two list adds when the frag can get
dropped). With this fix applied I couldn't kill the same machine in 24
hours with the same setup.

Fixes: 3ef0eb0db4bf ("net: frag, move LRU list maintenance outside of
rwlock")

CC: Florian Westphal <fw@strlen.de>
CC: Jesper Dangaard Brouer <brouer@redhat.com>
CC: David S. Miller <davem@davemloft.net>

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: sctp: fix skb leakage in COOKIE ECHO path of chunk->auth_chunk

[ Upstream commit c485658bae87faccd7aed540fd2ca3ab37992310 ]

While working on ec0223ec48a9 ("net: sctp: fix sctp_sf_do_5_1D_ce to
verify if we/peer is AUTH capable"), we noticed that there's a skb
memory leakage in the error path.

Running the same reproducer as in ec0223ec48a9 and by unconditionally
jumping to the error label (to simulate an error condition) in
sctp_sf_do_5_1D_ce() receive path lets kmemleak detector bark about
the unfreed chunk->auth_chunk skb clone:

Unreferenced object 0xffff8800b8f3a000 (size 256):
  comm "softirq", pid 0, jiffies 4294769856 (age 110.757s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    89 ab 75 5e d4 01 58 13 00 00 00 00 00 00 00 00  ..u^..X.........
  backtrace:
    [<ffffffff816660be>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff8119f328>] kmem_cache_alloc+0xc8/0x210
    [<ffffffff81566929>] skb_clone+0x49/0xb0
    [<ffffffffa0467459>] sctp_endpoint_bh_rcv+0x1d9/0x230 [sctp]
    [<ffffffffa046fdbc>] sctp_inq_push+0x4c/0x70 [sctp]
    [<ffffffffa047e8de>] sctp_rcv+0x82e/0x9a0 [sctp]
    [<ffffffff815abd38>] ip_local_deliver_finish+0xa8/0x210
    [<ffffffff815a64af>] nf_reinject+0xbf/0x180
    [<ffffffffa04b4762>] nfqnl_recv_verdict+0x1d2/0x2b0 [nfnetlink_queue]
    [<ffffffffa04aa40b>] nfnetlink_rcv_msg+0x14b/0x250 [nfnetlink]
    [<ffffffff815a3269>] netlink_rcv_skb+0xa9/0xc0
    [<ffffffffa04aa7cf>] nfnetlink_rcv+0x23f/0x408 [nfnetlink]
    [<ffffffff815a2bd8>] netlink_unicast+0x168/0x250
    [<ffffffff815a2fa1>] netlink_sendmsg+0x2e1/0x3f0
    [<ffffffff8155cc6b>] sock_sendmsg+0x8b/0xc0
    [<ffffffff8155d449>] ___sys_sendmsg+0x369/0x380

What happens is that commit bbd0d59809f9 clones the skb containing
the AUTH chunk in sctp_endpoint_bh_rcv() when having the edge case
that an endpoint requires COOKIE-ECHO chunks to be authenticated:

  ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ---------->
  <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] ---------
  ------------------ AUTH; COOKIE-ECHO ---------------->
  <-------------------- COOKIE-ACK ---------------------

When we enter sctp_sf_do_5_1D_ce() and before we actually get to
the point where we process (and subsequently free) a non-NULL
chunk->auth_chunk, we could hit the "goto nomem_init" path from
an error condition and thus leave the cloned skb around w/o
freeing it.

The fix is to centrally free such clones in sctp_chunk_destroy()
handler that is invoked from sctp_chunk_free() after all refs have
dropped; and also move both kfree_skb(chunk->auth_chunk) there,
so that chunk->auth_chunk is either NULL (since sctp_chunkify()
allocs new chunks through kmem_cache_zalloc()) or non-NULL with
a valid skb pointer. chunk->skb and chunk->auth_chunk are the
only skbs in the sctp_chunk structure that need to be handeled.

While at it, we should use consume_skb() for both. It is the same
as dev_kfree_skb() but more appropriately named as we are not
a device but a protocol. Also, this effectively replaces the
kfree_skb() from both invocations into consume_skb(). Functions
are the same only that kfree_skb() assumes that the frame was
being dropped after a failure (e.g. for tools like drop monitor),
usage of consume_skb() seems more appropriate in function
sctp_chunk_destroy() though.

Fixes: bbd0d59809f9 ("[SCTP]: Implement the receive and verification of AUTH chunk")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Vlad Yasevich <yasevich@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bridge: multicast: add sanity check for query source addresses

[ Upstream commit 6565b9eeef194afbb3beec80d6dd2447f4091f8c ]

MLD queries are supposed to have an IPv6 link-local source address
according to RFC2710, section 4 and RFC3810, section 5.1.14. This patch
adds a sanity check to ignore such broken MLD queries.

Without this check, such malformed MLD queries can result in a
denial of service: The queries are ignored by any MLD listener
therefore they will not respond with an MLD report. However,
without this patch these malformed MLD queries would enable the
snooping part in the bridge code, potentially shutting down the
according ports towards these hosts for multicast traffic as the
bridge did not learn about these listeners.

Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
inet: frag: make sure forced eviction removes all frags

[ Upstream commit e588e2f286ed7da011ed357c24c5b9a554e26595 ]

Quoting Alexander Aring:
  While fragmentation and unloading of 6lowpan module I got this kernel Oops
  after few seconds:

  BUG: unable to handle kernel paging request at f88bbc30
  [..]
  Modules linked in: ipv6 [last unloaded: 6lowpan]
  Call Trace:
   [<c012af4c>] ? call_timer_fn+0x54/0xb3
   [<c012aef8>] ? process_timeout+0xa/0xa
   [<c012b66b>] run_timer_softirq+0x140/0x15f

Problem is that incomplete frags are still around after unload; when
their frag expire timer fires, we get crash.

When a netns is removed (also done when unloading module), inet_frag
calls the evictor with 'force' argument to purge remaining frags.

The evictor loop terminates when accounted memory ('work') drops to 0
or the lru-list becomes empty.  However, the mem accounting is done
via percpu counters and may not be accurate, i.e. loop may terminate
prematurely.

Alter evictor to only stop once the lru list is empty when force is
requested.

Reported-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Reported-by: Alexander Aring <alex.aring@gmail.com>
Tested-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>