commit 8e4b7205 upstream.

Since commit acb2505d ("openrisc: fix copy_from_user()"),
copy_from_user() returns the number of bytes requested, not the
number of bytes not copied.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Fixes: acb2505d ("openrisc: fix copy_from_user()")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 65c0044c upstream.

avr32 builds fail with:

arch/avr32/kernel/built-in.o: In function `arch_ptrace':
(.text+0x650): undefined reference to `___copy_from_user'
arch/avr32/kernel/built-in.o:(___ksymtab+___copy_from_user+0x0): undefined
reference to `___copy_from_user'
kernel/built-in.o: In function `proc_doulongvec_ms_jiffies_minmax':
(.text+0x5dd8): undefined reference to `___copy_from_user'
kernel/built-in.o: In function `proc_dointvec_minmax_sysadmin':
sysctl.c:(.text+0x6174): undefined reference to `___copy_from_user'
kernel/built-in.o: In function `ptrace_has_cap':
ptrace.c:(.text+0x69c0): undefined reference to `___copy_from_user'
kernel/built-in.o:ptrace.c:(.text+0x6b90): more undefined references to
`___copy_from_user' follow

Fixes: 8630c322 ("avr32: fix copy_from_user()")
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Havard Skinnemoen <hskinnemoen@gmail.com>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 8ab86c00 upstream.

skb is not freed if newsk is NULL. Rework the error path so free_skb is
unconditionally called on function exit.

Fixes: c3ea9fa2 ("[IrDA] af_irda: IRDA_ASSERT cleanups")
Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 344bacca upstream.

This fix solves a race between light flush and on the fly joins.
Light flush doesn't set the device to down and unset IPOIB_OPER_UP
flag, this means that if while flushing we have a MC join in progress
and the QP was attached to BC MGID we can have a mismatches when
re-attaching a QP to the BC MGID.

The light flush would set the broadcast group to NULL causing an on
the fly join to rejoin and reattach to the BC MCG as well as adding
the BC MGID to the multicast list. The flush process would later on
remove the BC MGID and detach it from the QP. On the next flush
the BC MGID is present in the multicast list but not found when trying
to detach it because of the previous double attach and single detach.

[18332.714265] ------------[ cut here ]------------
[18332.717775] WARNING: CPU: 6 PID: 3767 at drivers/infiniband/core/verbs.c:280 ib_dealloc_pd+0xff/0x120 [ib_core]
...
[18332.775198] Hardware name: Red Hat KVM, BIOS Bochs 01/01/2011
[18332.779411]  0000000000000000 ffff8800b50dfbb0 ffffffff813fed47 0000000000000000
[18332.784960]  0000000000000000 ffff8800b50dfbf0 ffffffff8109add1 0000011832f58300
[18332.790547]  ffff880226a596c0 ffff880032482000 ffff880032482830 ffff880226a59280
[18332.796199] Call Trace:
[18332.798015]  [<ffffffff813fed47>] dump_stack+0x63/0x8c
[18332.801831]  [<ffffffff8109add1>] __warn+0xd1/0xf0
[18332.805403]  [<ffffffff8109aebd>] warn_slowpath_null+0x1d/0x20
[18332.809706]  [<ffffffffa025d90f>] ib_dealloc_pd+0xff/0x120 [ib_core]
[18332.814384]  [<ffffffffa04f3d7c>] ipoib_transport_dev_cleanup+0xfc/0x1d0 [ib_ipoib]
[18332.820031]  [<ffffffffa04ed648>] ipoib_ib_dev_cleanup+0x98/0x110 [ib_ipoib]
[18332.825220]  [<ffffffffa04e62c8>] ipoib_dev_cleanup+0x2d8/0x550 [ib_ipoib]
[18332.830290]  [<ffffffffa04e656f>] ipoib_uninit+0x2f/0x40 [ib_ipoib]
[18332.834911]  [<ffffffff81772a8a>] rollback_registered_many+0x1aa/0x2c0
[18332.839741]  [<ffffffff81772bd1>] rollback_registered+0x31/0x40
[18332.844091]  [<ffffffff81773b18>] unregister_netdevice_queue+0x48/0x80
[18332.848880]  [<ffffffffa04f489b>] ipoib_vlan_delete+0x1fb/0x290 [ib_ipoib]
[18332.853848]  [<ffffffffa04df1cd>] delete_child+0x7d/0xf0 [ib_ipoib]
[18332.858474]  [<ffffffff81520c08>] dev_attr_store+0x18/0x30
[18332.862510]  [<ffffffff8127fe4a>] sysfs_kf_write+0x3a/0x50
[18332.866349]  [<ffffffff8127f4e0>] kernfs_fop_write+0x120/0x170
[18332.870471]  [<ffffffff81207198>] __vfs_write+0x28/0xe0
[18332.874152]  [<ffffffff810e09bf>] ? percpu_down_read+0x1f/0x50
[18332.878274]  [<ffffffff81208062>] vfs_write+0xa2/0x1a0
[18332.881896]  [<ffffffff812093a6>] SyS_write+0x46/0xa0
[18332.885632]  [<ffffffff810039b7>] do_syscall_64+0x57/0xb0
[18332.889709]  [<ffffffff81883321>] entry_SYSCALL64_slow_path+0x25/0x25
[18332.894727] ---[ end trace 09ebbe31f831ef17 ]---

Fixes: ee1e2c82 ("IPoIB: Refresh paths instead of flushing them on SM change events")
Signed-off-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 08c5cd37 upstream.

Some full-speed mceusb infrared transceivers contain invalid endpoint
descriptors for their interrupt endpoints, with bInterval set to 0.
In the past they have worked out okay with the mceusb driver, because
the driver sets the bInterval field in the descriptor to 1,
overwriting whatever value may have been there before.  However, this
approach was never sanctioned by the USB core, and in fact it does not
work with xHCI controllers, because they use the bInterval value that
was present when the configuration was installed.

Currently usbcore uses 32 ms as the default interval if the value in
the endpoint descriptor is invalid.  It turns out that these IR
transceivers don't work properly unless the interval is set to 10 ms
or below.  To work around this mceusb problem, this patch changes the
endpoint-descriptor parsing routine, making the default interval value
be 10 ms rather than 32 ms.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Wade Berrier <wberrier@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 8630c322 upstream.

really ugly, but apparently avr32 compilers turns access_ok() into
something so bad that they want it in assembler.  Left that way,
zeroing added in inline wrapper.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit e98b9e37 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit d0cf3851 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit c90a3bc5 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 8f035983 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 917400ce upstream.
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 6e050503 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit c6852389 upstream.

It could be done in exception-handling bits in __get_user_b() et.al.,
but the surgery involved would take more knowledge of sh64 details
than I have or _want_ to have.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit b615e3c7 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit c2f18fa4 upstream.

* should zero on any failure
* __get_user() should use __copy_from_user(), not copy_from_user()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit fd2d2b19 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 22426465 upstream.

should clear on access_ok() failures.  Also remove the useless
range truncation logics.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: no calls to check_object_size()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit aace880f upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit acb2505d upstream.

... that should zero on faults.  Also remove the <censored> helpful
logics wrt range truncation copied from ppc32.  Where it had ever
been needed only in case of copy_from_user() *and* had not been merged
into the mainline until a month after the need had disappeared.
A decade before openrisc went into mainline, I might add...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit ae7cc577 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: include <linux/string.h> to get declaration of memset()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 43403eab upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit a5e541f7 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: no calls to check_object_size()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit f35c1e06 upstream.

It's -EFAULT, not -1 (and contrary to the comment in there,
__strnlen_user() can return 0 - on faults).
Acked-by: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 3b8767a8 upstream.

It should check access_ok().  Otherwise a bunch of places turn into
trivially exploitable rootholes.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit eb47e029 upstream.

* copy_from_user() on access_ok() failure ought to zero the destination
* none of those primitives should skip the access_ok() check in case of
small constant size.
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 9ad18b75 upstream.

both for access_ok() failures and for faults halfway through
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit acdb04d0 upstream.

When we need to allocate a temporary blkcipher_walk_next and it
fails, the code is supposed to take the slow path of processing
the data block by block.  However, due to an unrelated change
we instead end up dereferencing the NULL pointer.

This patch fixes it by moving the unrelated bsize setting out
of the way so that we enter the slow path as inteded.

Fixes: 7607bd8f ("[CRYPTO] blkcipher: Added blkcipher_walk_virt_block")
Reported-by: xiakaixu <xiakaixu@huawei.com>
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[bwh: Backported to 3.2: s/walk_blocksize/blocksize/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 06dfe5cc upstream.

SA1111 PCMCIA was broken when PCMCIA switched to using dev_pm_ops for
the PCMCIA socket class.  PCMCIA used to handle suspend/resume via the
socket hosting device, which happened at normal device suspend/resume
time.

However, the referenced commit changed this: much of the resume now
happens much earlier, in the noirq resume handler of dev_pm_ops.

However, on SA1111, the PCMCIA device is not accessible as the SA1111
has not been resumed at _noirq time.  It's slightly worse than that,
because the SA1111 has already been put to sleep at _noirq time, so
suspend doesn't work properly.

Fix this by converting the core SA1111 code to use dev_pm_ops as well,
and performing its own suspend/resume at noirq time.

This fixes these errors in the kernel log:

pcmcia_socket pcmcia_socket0: time out after reset
pcmcia_socket pcmcia_socket1: time out after reset

and the resulting lack of PCMCIA cards after a S2RAM cycle.

Fixes: d7646f76 ("pcmcia: use dev_pm_ops for class pcmcia_socket_class")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit b519d408 upstream.

Ensure that we conform to the algorithm described in RFC5661, section
18.36.4 for when to bump the sequence id. In essence we do it for all
cases except when the RPC call timed out, or in case of the server returning
NFS4ERR_DELAY or NFS4ERR_STALE_CLIENTID.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
[bwh: Backported to 3.2:
 - Add the 'out' label
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit f6d7c1b5 upstream.

This fixes subpage writes when using 4-bit HW ECC.

There has been numerous reports about ECC errors with devices using this
driver for a while.  Also the 4-bit ECC has been reported as broken with
subpages in [1] and with 16 bits NANDs in the driver and in mach* board
files both in mainline and in the vendor BSPs.

What I saw with 4-bit ECC on a 16bits NAND (on an LCDK) which got me to
try reinitializing the ECC engine:
- R/W on whole pages properly generates/checks RS code
- try writing the 1st subpage only of a blank page, the subpage is well
  written and the RS code properly generated, re-reading the same page
  the HW detects some ECC error, reading the same page again no ECC
  error is detected

Note that the ECC engine is already reinitialized in the 1-bit case.

Tested on my LCDK with UBI+UBIFS using subpages.
This could potentially get rid of the issue workarounded in [1].

[1] 28c015a9 ("mtd: davinci-nand: disable subpage write for keystone-nand")

Fixes: 6a4123e5 ("mtd: nand: davinci_nand, 4-bit ECC for smallpage")
Signed-off-by: Karl Beldan <kbeldan@baylibre.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 2545e5da upstream.

... in all cases, including the failing access_ok()

Note that some architectures using asm-generic/uaccess.h have
__copy_from_user() not zeroing the tail on failure halfway
through.  This variant works either way.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 2561d309 upstream.

it should clear the destination even when access_ok() fails.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 2f30ea50 upstream.

When we fail to attach the security context in xfrm_state_construct()
we'll return 0 as error value which, in turn, will wrongly claim success
to userland when, in fact, we won't be adding / updating the XFRM state.

This is a regression introduced by commit fd21150a ("[XFRM] netlink:
Inline attach_encap_tmpl(), attach_sec_ctx(), and attach_one_addr()").

Fix it by propagating the error returned by security_xfrm_state_alloc()
in this case.

Fixes: fd21150a ("[XFRM] netlink: Inline attach_encap_tmpl()...")
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 816f318b upstream.

When a seq-virmidi driver is initialized, it registers a rawmidi
instance with its callback to create an associated seq kernel client.
Currently it's done throughly in rawmidi's register_mutex context.
Recently it was found that this may lead to a deadlock another rawmidi
device that is being attached with the sequencer is accessed, as both
open with the same register_mutex.  This was actually triggered by
syzkaller, as Dmitry Vyukov reported:

======================================================
 [ INFO: possible circular locking dependency detected ]
 4.8.0-rc1+ #11 Not tainted
 -------------------------------------------------------
 syz-executor/7154 is trying to acquire lock:
  (register_mutex#5){+.+.+.}, at: [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341

 but task is already holding lock:
  (&grp->list_mutex){++++.+}, at: [<ffffffff850138bb>] check_and_subscribe_port+0x5b/0x5c0 sound/core/seq/seq_ports.c:495

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&grp->list_mutex){++++.+}:
    [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746
    [<ffffffff863f6199>] down_read+0x49/0xc0 kernel/locking/rwsem.c:22
    [<     inline     >] deliver_to_subscribers sound/core/seq/seq_clientmgr.c:681
    [<ffffffff85005c5e>] snd_seq_deliver_event+0x35e/0x890 sound/core/seq/seq_clientmgr.c:822
    [<ffffffff85006e96>] > snd_seq_kernel_client_dispatch+0x126/0x170 sound/core/seq/seq_clientmgr.c:2418
    [<ffffffff85012c52>] snd_seq_system_broadcast+0xb2/0xf0 sound/core/seq/seq_system.c:101
    [<ffffffff84fff70a>] snd_seq_create_kernel_client+0x24a/0x330 sound/core/seq/seq_clientmgr.c:2297
    [<     inline     >] snd_virmidi_dev_attach_seq sound/core/seq/seq_virmidi.c:383
    [<ffffffff8502d29f>] snd_virmidi_dev_register+0x29f/0x750 sound/core/seq/seq_virmidi.c:450
    [<ffffffff84fd208c>] snd_rawmidi_dev_register+0x30c/0xd40 sound/core/rawmidi.c:1645
    [<ffffffff84f816d3>] __snd_device_register.part.0+0x63/0xc0 sound/core/device.c:164
    [<     inline     >] __snd_device_register sound/core/device.c:162
    [<ffffffff84f8235d>] snd_device_register_all+0xad/0x110 sound/core/device.c:212
    [<ffffffff84f7546f>] snd_card_register+0xef/0x6c0 sound/core/init.c:749
    [<ffffffff85040b7f>] snd_virmidi_probe+0x3ef/0x590 sound/drivers/virmidi.c:123
    [<ffffffff833ebf7b>] platform_drv_probe+0x8b/0x170 drivers/base/platform.c:564
    ......

 -> #0 (register_mutex#5){+.+.+.}:
    [<     inline     >] check_prev_add kernel/locking/lockdep.c:1829
    [<     inline     >] check_prevs_add kernel/locking/lockdep.c:1939
    [<     inline     >] validate_chain kernel/locking/lockdep.c:2266
    [<ffffffff814791f4>] __lock_acquire+0x4d44/0x4d80 kernel/locking/lockdep.c:3335
    [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746
    [<     inline     >] __mutex_lock_common kernel/locking/mutex.c:521
    [<ffffffff863f0ef1>] mutex_lock_nested+0xb1/0xa20 kernel/locking/mutex.c:621
    [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341
    [<ffffffff8502e7c7>] midisynth_subscribe+0xf7/0x350 sound/core/seq/seq_midi.c:188
    [<     inline     >] subscribe_port sound/core/seq/seq_ports.c:427
    [<ffffffff85013cc7>] check_and_subscribe_port+0x467/0x5c0 sound/core/seq/seq_ports.c:510
    [<ffffffff85015da9>] snd_seq_port_connect+0x2c9/0x500 sound/core/seq/seq_ports.c:579
    [<ffffffff850079b8>] snd_seq_ioctl_subscribe_port+0x1d8/0x2b0 sound/core/seq/seq_clientmgr.c:1480
    [<ffffffff84ffe9e4>] snd_seq_do_ioctl+0x184/0x1e0 sound/core/seq/seq_clientmgr.c:2225
    [<ffffffff84ffeae8>] snd_seq_kernel_client_ctl+0xa8/0x110 sound/core/seq/seq_clientmgr.c:2440
    [<ffffffff85027664>] snd_seq_oss_midi_open+0x3b4/0x610 sound/core/seq/oss/seq_oss_midi.c:375
    [<ffffffff85023d67>] snd_seq_oss_synth_setup_midi+0x107/0x4c0 sound/core/seq/oss/seq_oss_synth.c:281
    [<ffffffff8501b0a8>] snd_seq_oss_open+0x748/0x8d0 sound/core/seq/oss/seq_oss_init.c:274
    [<ffffffff85019d8a>] odev_open+0x6a/0x90 sound/core/seq/oss/seq_oss.c:138
    [<ffffffff84f7040f>] soundcore_open+0x30f/0x640 sound/sound_core.c:639
    ......

 other info that might help us debug this:

 Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&grp->list_mutex);
                                lock(register_mutex#5);
                                lock(&grp->list_mutex);
   lock(register_mutex#5);

 *** DEADLOCK ***
======================================================

The fix is to simply move the registration parts in
snd_rawmidi_dev_register() to the outside of the register_mutex lock.
The lock is needed only to manage the linked list, and it's not
necessarily to cover the whole initialization process.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 9f8a7658 upstream.

When a user timer instance is continued without the explicit start
beforehand, the system gets eventually zero-division error like:

  divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
  CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
   task: ffff88003c9b2280 task.stack: ffff880027280000
   RIP: 0010:[<ffffffff858e1a6c>]  [<     inline     >] ktime_divns include/linux/ktime.h:195
   RIP: 0010:[<ffffffff858e1a6c>]  [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62
  Call Trace:
   <IRQ>
   [<     inline     >] __run_hrtimer kernel/time/hrtimer.c:1238
   [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302
   [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336
   [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933
   [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957
   [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487
   <EOI>
   .....

Although a similar issue was spotted and a fix patch was merged in
commit [6b760bb2: ALSA: timer: fix division by zero after
SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of
iceberg.

In this patch, we fix the issue a bit more drastically.  Basically the
continue of an uninitialized timer is supposed to be a fresh start, so
we do it for user timers.  For the direct snd_timer_continue() call,
there is no way to pass the initial tick value, so we kick out for the
uninitialized case.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.2:
 - Adjust context
 - In _snd_timer_stop(), check the value of 'event' instead of 'stop']
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit c3b16813 upstream.

This is a minor code cleanup without any functional changes:
- Kill keep_flag argument from _snd_timer_stop(), as all callers pass
  only it false.
- Remove redundant NULL check in _snd_timer_stop().
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.2: adjust to apply after previously backported
 "ALSA: timer: Fix race between stop and interrupt"]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 0bd22235 upstream.

When calling .import() on a cryptd ahash_request, the structure members
that describe the child transform in the shash_desc need to be initialized
like they are when calling .init()
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 135e8c92 upstream.

The origin of the issue I've seen is related to
a missing memory barrier between check for task->state and
the check for task->on_rq.

The task being woken up is already awake from a schedule()
and is doing the following:

	do {
		schedule()
		set_current_state(TASK_(UN)INTERRUPTIBLE);
	} while (!cond);

The waker, actually gets stuck doing the following in
try_to_wake_up():

	while (p->on_cpu)
		cpu_relax();

Analysis:

The instance I've seen involves the following race:

 CPU1					CPU2

 while () {
   if (cond)
     break;
   do {
     schedule();
     set_current_state(TASK_UN..)
   } while (!cond);
					wakeup_routine()
					  spin_lock_irqsave(wait_lock)
   raw_spin_lock_irqsave(wait_lock)	  wake_up_process()
 }					  try_to_wake_up()
 set_current_state(TASK_RUNNING);	  ..
 list_del(&waiter.list);

CPU2 wakes up CPU1, but before it can get the wait_lock and set
current state to TASK_RUNNING the following occurs:

 CPU3
 wakeup_routine()
 raw_spin_lock_irqsave(wait_lock)
 if (!list_empty)
   wake_up_process()
   try_to_wake_up()
   raw_spin_lock_irqsave(p->pi_lock)
   ..
   if (p->on_rq && ttwu_wakeup())
   ..
   while (p->on_cpu)
     cpu_relax()
   ..

CPU3 tries to wake up the task on CPU1 again since it finds
it on the wait_queue, CPU1 is spinning on wait_lock, but immediately
after CPU2, CPU3 got it.

CPU3 checks the state of p on CPU1, it is TASK_UNINTERRUPTIBLE and
the task is spinning on the wait_lock. Interestingly since p->on_rq
is checked under pi_lock, I've noticed that try_to_wake_up() finds
p->on_rq to be 0. This was the most confusing bit of the analysis,
but p->on_rq is changed under runqueue lock, rq_lock, the p->on_rq
check is not reliable without this fix IMHO. The race is visible
(based on the analysis) only when ttwu_queue() does a remote wakeup
via ttwu_queue_remote. In which case the p->on_rq change is not
done uder the pi_lock.

The result is that after a while the entire system locks up on
the raw_spin_irqlock_save(wait_lock) and the holder spins infintely

Reproduction of the issue:

The issue can be reproduced after a long run on my system with 80
threads and having to tweak available memory to very low and running
memory stress-ng mmapfork test. It usually takes a long time to
reproduce. I am trying to work on a test case that can reproduce
the issue faster, but thats work in progress. I am still testing the
changes on my still in a loop and the tests seem OK thus far.

Big thanks to Benjamin and Nick for helping debug this as well.
Ben helped catch the missing barrier, Nick caught every missing
bit in my theory.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[ Updated comment to clarify matching barriers. Many
  architectures do not have a full barrier in switch_to()
  so that cannot be relied upon. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <nicholas.piggin@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/e02cce7b-d9ca-1ad0-7a61-ea97c7582b37@gmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 307fe9dd upstream.

All the scaling of the KXSD9 involves multiplication with a
fraction number < 1.

However the scaling value returned from IIO_INFO_SCALE was
unpredictable as only the micros of the value was assigned, and
not the integer part, resulting in scaling like this:

$cat in_accel_scale
-1057462640.011978

Fix this by assigning zero to the integer part.
Tested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 546481c2 upstream.

When a new CM connection is being requested, ipoib driver copies data
from the path pointer in the CM/tx object, the path object might be
invalid at the point and memory corruption will happened later when now
the CM driver will try using that data.

The next scenario demonstrates it:
	neigh_add_path --> ipoib_cm_create_tx -->
	queue_work (pointer to path is in the cm/tx struct)
	#while the work is still in the queue,
	#the port goes down and causes the ipoib_flush_paths:
	ipoib_flush_paths --> path_free --> kfree(path)
	#at this point the work scheduled starts.
	ipoib_cm_tx_start --> copy from the (invalid)path pointer:
	(memcpy(&pathrec, &p->path->pathrec, sizeof pathrec);)
	 -> memory corruption.

To fix that the driver now starts the CM/tx connection only if that
specific path exists in the general paths database.
This check is protected with the relevant locks, and uses the gid from
the neigh member in the CM/tx object which is valid according to the ref
count that was taken by the CM/tx.

Fixes: 839fcaba ('IPoIB: Connected mode experimental support')
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
[bwh: Backported to 3.2: s/neigh->daddr/neigh->neighbour->ha/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>