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484,581 commits

Author SHA1 Message Date
Jason Wang
0b5ee81826 kvm: fix double free for fast mmio eventfd
[ Upstream commit eefd6b06b1 ]

We register wildcard mmio eventfd on two buses, once for KVM_MMIO_BUS
and once on KVM_FAST_MMIO_BUS but with a single iodev
instance. This will lead to an issue: kvm_io_bus_destroy() knows
nothing about the devices on two buses pointing to a single dev. Which
will lead to double free[1] during exit. Fix this by allocating two
instances of iodevs then registering one on KVM_MMIO_BUS and another
on KVM_FAST_MMIO_BUS.

CPU: 1 PID: 2894 Comm: qemu-system-x86 Not tainted 3.19.0-26-generic #28-Ubuntu
Hardware name: LENOVO 2356BG6/2356BG6, BIOS G7ET96WW (2.56 ) 09/12/2013
task: ffff88009ae0c4b0 ti: ffff88020e7f0000 task.ti: ffff88020e7f0000
RIP: 0010:[<ffffffffc07e25d8>]  [<ffffffffc07e25d8>] ioeventfd_release+0x28/0x60 [kvm]
RSP: 0018:ffff88020e7f3bc8  EFLAGS: 00010292
RAX: dead000000200200 RBX: ffff8801ec19c900 RCX: 000000018200016d
RDX: ffff8801ec19cf80 RSI: ffffea0008bf1d40 RDI: ffff8801ec19c900
RBP: ffff88020e7f3bd8 R08: 000000002fc75a01 R09: 000000018200016d
R10: ffffffffc07df6ae R11: ffff88022fc75a98 R12: ffff88021e7cc000
R13: ffff88021e7cca48 R14: ffff88021e7cca50 R15: ffff8801ec19c880
FS:  00007fc1ee3e6700(0000) GS:ffff88023e240000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f389d8000 CR3: 000000023dc13000 CR4: 00000000001427e0
Stack:
ffff88021e7cc000 0000000000000000 ffff88020e7f3be8 ffffffffc07e2622
ffff88020e7f3c38 ffffffffc07df69a ffff880232524160 ffff88020e792d80
 0000000000000000 ffff880219b78c00 0000000000000008 ffff8802321686a8
Call Trace:
[<ffffffffc07e2622>] ioeventfd_destructor+0x12/0x20 [kvm]
[<ffffffffc07df69a>] kvm_put_kvm+0xca/0x210 [kvm]
[<ffffffffc07df818>] kvm_vcpu_release+0x18/0x20 [kvm]
[<ffffffff811f69f7>] __fput+0xe7/0x250
[<ffffffff811f6bae>] ____fput+0xe/0x10
[<ffffffff81093f04>] task_work_run+0xd4/0xf0
[<ffffffff81079358>] do_exit+0x368/0xa50
[<ffffffff81082c8f>] ? recalc_sigpending+0x1f/0x60
[<ffffffff81079ad5>] do_group_exit+0x45/0xb0
[<ffffffff81085c71>] get_signal+0x291/0x750
[<ffffffff810144d8>] do_signal+0x28/0xab0
[<ffffffff810f3a3b>] ? do_futex+0xdb/0x5d0
[<ffffffff810b7028>] ? __wake_up_locked_key+0x18/0x20
[<ffffffff810f3fa6>] ? SyS_futex+0x76/0x170
[<ffffffff81014fc9>] do_notify_resume+0x69/0xb0
[<ffffffff817cb9af>] int_signal+0x12/0x17
Code: 5d c3 90 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 8b 7f 20 e8 06 d6 a5 c0 48 8b 43 08 48 8b 13 48 89 df 48 89 42 08 <48> 89 10 48 b8 00 01 10 00 00
 RIP  [<ffffffffc07e25d8>] ioeventfd_release+0x28/0x60 [kvm]
 RSP <ffff88020e7f3bc8>

Cc: stable@vger.kernel.org
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 22:12:51 -04:00
Jason Wang
7642b3f109 kvm: factor out core eventfd assign/deassign logic
[ Upstream commit 85da11ca58 ]

This patch factors out core eventfd assign/deassign logic and leaves
the argument checking and bus index selection to callers.

Cc: stable@vger.kernel.org
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 22:12:50 -04:00
Jason Wang
7d765ce07e kvm: fix zero length mmio searching
[ Upstream commit 8f4216c7d2 ]

Currently, if we had a zero length mmio eventfd assigned on
KVM_MMIO_BUS. It will never be found by kvm_io_bus_cmp() since it
always compares the kvm_io_range() with the length that guest
wrote. This will cause e.g for vhost, kick will be trapped by qemu
userspace instead of vhost. Fixing this by using zero length if an
iodevice is zero length.

Cc: stable@vger.kernel.org
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 22:12:49 -04:00
Jason Wang
d758df24a5 kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd
[ Upstream commit 8453fecbec ]

We only want zero length mmio eventfd to be registered on
KVM_FAST_MMIO_BUS. So check this explicitly when arg->len is zero to
make sure this.

Cc: stable@vger.kernel.org
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 22:12:48 -04:00
Marek Majtyka
45258bdd7f arm: KVM: Fix incorrect device to IPA mapping
[ Upstream commit ca09f02f12 ]

A critical bug has been found in device memory stage1 translation for
VMs with more then 4GB of address space. Once vm_pgoff size is smaller
then pa (which is true for LPAE case, u32 and u64 respectively) some
more significant bits of pa may be lost as a shift operation is performed
on u32 and later cast onto u64.

Example: vm_pgoff(u32)=0x00210030, PAGE_SHIFT=12
        expected pa(u64):   0x0000002010030000
        produced pa(u64):   0x0000000010030000

The fix is to change the order of operations (casting first onto phys_addr_t
and then shifting).

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
[maz: fixed changelog and patch formatting]
Cc: stable@vger.kernel.org
Signed-off-by: Marek Majtyka <marek.majtyka@tieto.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 22:12:47 -04:00
Kyle Evans
3cd079e563 hp-wmi: limit hotkey enable
[ Upstream commit 8a1513b493 ]

Do not write initialize magic on systems that do not have
feature query 0xb. Fixes Bug #82451.

Redefine FEATURE_QUERY to align with 0xb and FEATURE2 with 0xd
for code clearity.

Add a new test function, hp_wmi_bios_2008_later() & simplify
hp_wmi_bios_2009_later(), which fixes a bug in cases where
an improper value is returned. Probably also fixes Bug #69131.

Add missing __init tag.

Signed-off-by: Kyle Evans <kvans32@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 22:12:47 -04:00
Luis Henriques
2889a072fc zram: fix possible use after free in zcomp_create()
[ Upstream commit 3aaf14da80 ]

zcomp_create() verifies the success of zcomp_strm_{multi,single}_create()
through comp->stream, which can potentially be pointing to memory that
was freed if these functions returned an error.

While at it, replace a 'ERR_PTR(-ENOMEM)' by a more generic
'ERR_PTR(error)' as in the future zcomp_strm_{multi,siggle}_create()
could return other error codes.  Function documentation updated
accordingly.

Fixes: beca3ec71f ("zram: add multi stream functionality")
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 22:12:45 -04:00
Stas Sergeev
71a386c7a6 of_mdio: add new DT property 'managed' to specify the PHY management type
[ Upstream commit 4cba5c2103 ]

Currently the PHY management type is selected by the MAC driver arbitrary.
The decision is based on the presence of the "fixed-link" node and on a
will of the driver's authors.
This caused a regression recently, when mvneta driver suddenly started
to use the in-band status for auto-negotiation on fixed links.
It appears the auto-negotiation may not work when expected by the MAC driver.
Sebastien Rannou explains:
<< Yes, I confirm that my HW does not generate an in-band status. AFAIK, it's
a PHY that aggregates 4xSGMIIs to 1xQSGMII ; the MAC side of the PHY (with
inband status) is connected to the switch through QSGMII, and in this context
we are on the media side of the PHY. >>
https://lkml.org/lkml/2015/7/10/206

This patch introduces the new string property 'managed' that allows
the user to set the management type explicitly.
The supported values are:
"auto" - default. Uses either MDIO or nothing, depending on the presence
of the fixed-link node
"in-band-status" - use in-band status

Signed-off-by: Stas Sergeev <stsp@users.sourceforge.net>

CC: Rob Herring <robh+dt@kernel.org>
CC: Pawel Moll <pawel.moll@arm.com>
CC: Mark Rutland <mark.rutland@arm.com>
CC: Ian Campbell <ijc+devicetree@hellion.org.uk>
CC: Kumar Gala <galak@codeaurora.org>
CC: Florian Fainelli <f.fainelli@gmail.com>
CC: Grant Likely <grant.likely@linaro.org>
CC: devicetree@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:12 -04:00
Florian Fainelli
c0fb099370 net: dsa: bcm_sf2: Do not override speed settings
[ Upstream commit d2eac98f7d ]

The SF2 driver currently overrides speed settings for its port
configured using a fixed PHY, this is both unnecessary and incorrect,
because we keep feedback to the hardware parameters that we read from
the PHY device, which in the case of a fixed PHY cannot possibly change
speed.

This is a required change to allow the fixed PHY code to allow
registering a PHY with a link configured as DOWN by default and avoid
some sort of circular dependency where we require the link_update
callback to run to program the hardware, and we then utilize the fixed
PHY parameters to program the hardware with the same settings.

Fixes: 246d7f773c ("net: dsa: add Broadcom SF2 switch driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:11 -04:00
Eric Dumazet
9a2c1f52a4 tcp: add proper TS val into RST packets
[ Upstream commit 675ee231d9 ]

RST packets sent on behalf of TCP connections with TS option (RFC 7323
TCP timestamps) have incorrect TS val (set to 0), but correct TS ecr.

A > B: Flags [S], seq 0, win 65535, options [mss 1000,nop,nop,TS val 100
ecr 0], length 0
B > A: Flags [S.], seq 2444755794, ack 1, win 28960, options [mss
1460,nop,nop,TS val 7264344 ecr 100], length 0
A > B: Flags [.], ack 1, win 65535, options [nop,nop,TS val 110 ecr
7264344], length 0

B > A: Flags [R.], seq 1, ack 1, win 28960, options [nop,nop,TS val 0
ecr 110], length 0

We need to call skb_mstamp_get() to get proper TS val,
derived from skb->skb_mstamp

Note that RFC 1323 was advocating to not send TS option in RST segment,
but RFC 7323 recommends the opposite :

  Once TSopt has been successfully negotiated, that is both <SYN> and
  <SYN,ACK> contain TSopt, the TSopt MUST be sent in every non-<RST>
  segment for the duration of the connection, and SHOULD be sent in an
  <RST> segment (see Section 5.2 for details)

Note this RFC recommends to send TS val = 0, but we believe it is
premature : We do not know if all TCP stacks are properly
handling the receive side :

   When an <RST> segment is
   received, it MUST NOT be subjected to the PAWS check by verifying an
   acceptable value in SEG.TSval, and information from the Timestamps
   option MUST NOT be used to update connection state information.
   SEG.TSecr MAY be used to provide stricter <RST> acceptance checks.

In 5 years, if/when all TCP stack are RFC 7323 ready, we might consider
to decide to send TS val = 0, if it buys something.

Fixes: 7faee5c0d5 ("tcp: remove TCP_SKB_CB(skb)->when")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:11 -04:00
Florian Fainelli
646cd5edbf net: dsa: bcm_sf2: Fix 64-bits register writes
[ Upstream commit 03679a1473 ]

The macro to write 64-bits quantities to the 32-bits register swapped
the value and offsets arguments, we want to preserve the ordering of the
arguments with respect to how writel() is implemented for instance:
value first, offset/base second.

Fixes: 246d7f773c ("net: dsa: add Broadcom SF2 switch driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:10 -04:00
Atsushi Nemoto
ca41797a86 net: eth: altera: fix napi poll_list corruption
[ Upstream commit 4548a697e4 ]

tse_poll() calls __napi_complete() with irq enabled.  This leads napi
poll_list corruption and may stop all napi drivers working.
Use napi_complete() instead of __napi_complete().

Signed-off-by: Atsushi Nemoto <nemoto@toshiba-tops.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:10 -04:00
Eric Sandeen
826d518a02 ext4: don't manipulate recovery flag when freezing no-journal fs
[ Upstream commit c642dc9e1a ]

At some point along this sequence of changes:

f6e63f9 ext4: fold ext4_nojournal_sops into ext4_sops
bb04457 ext4: support freezing ext2 (nojournal) file systems
9ca9238 ext4: Use separate super_operations structure for no_journal filesystems

ext4 started setting needs_recovery on filesystems without journals
when they are unfrozen.  This makes no sense, and in fact confuses
blkid to the point where it doesn't recognize the filesystem at all.

(freeze ext2; unfreeze ext2; run blkid; see no output; run dumpe2fs,
see needs_recovery set on fs w/ no journal).

To fix this, don't manipulate the INCOMPAT_RECOVER feature on
filesystems without journals.

Reported-by: Stu Mark <smark@datto.com>
Reviewed-by: Jan Kara <jack@suse.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:09 -04:00
Daniel Axtens
5324b25311 cxl: Fix unbalanced pci_dev_get in cxl_probe
[ Upstream commit 2925c2fdf1 ]

Currently the first thing we do in cxl_probe is to grab a reference
on the pci device. Later on, we call device_register on our adapter.
In our remove path, we call device_unregister, but we never call
pci_dev_put. We therefore leak the device every time we do a
reflash.

device_register/unregister is sufficient to hold the reference.
Therefore, drop the call to pci_dev_get.

Here's why this is safe.
The proposed cxl_probe(pdev) calls cxl_adapter_init:
    a) init calls cxl_adapter_alloc, which creates a struct cxl,
       conventionally called adapter. This struct contains a
       device entry, adapter->dev.

    b) init calls cxl_configure_adapter, where we set
       adapter->dev.parent = &dev->dev (here dev is the pci dev)

So at this point, the cxl adapter's device's parent is the PCI
device that I want to be refcounted properly.

    c) init calls cxl_register_adapter
       *) cxl_register_adapter calls device_register(&adapter->dev)

So now we're in device_register, where dev is the adapter device, and
we want to know if the PCI device is safe after we return.

device_register(&adapter->dev) calls device_initialize() and then
device_add().

device_add() does a get_device(). device_add() also explicitly grabs
the device's parent, and calls get_device() on it:

         parent = get_device(dev->parent);

So therefore, device_register() takes a lock on the parent PCI dev,
which is what pci_dev_get() was guarding. pci_dev_get() can therefore
be safely removed.

Fixes: f204e0b8ce ("cxl: Driver code for powernv PCIe based cards for userspace access")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:08 -04:00
Shota Suzuki
5be042b191 igb: Fix oops caused by missing queue pairing
[ Upstream commit 72ddef0506 ]

When initializing igb driver (e.g. 82576, I350), IGB_FLAG_QUEUE_PAIRS is
set if adapter->rss_queues exceeds half of max_rss_queues in
igb_init_queue_configuration().
On the other hand, IGB_FLAG_QUEUE_PAIRS is not set even if the number of
queues exceeds half of max_combined in igb_set_channels() when changing
the number of queues by "ethtool -L".
In this case, if numvecs is larger than MAX_MSIX_ENTRIES (10), the size
of adapter->msix_entries[], an overflow can occur in
igb_set_interrupt_capability(), which in turn leads to an oops.

Fix this problem as follows:
 - When changing the number of queues by "ethtool -L", set
   IGB_FLAG_QUEUE_PAIRS in the same way as initializing igb driver.
 - When increasing the size of q_vector, reallocate it appropriately.
   (With IGB_FLAG_QUEUE_PAIRS set, the size of q_vector gets larger.)

Another possible way to fix this problem is to cap the queues at its
initial number, which is the number of the initial online cpus. But this
is not the optimal way because we cannot increase queues when another
cpu becomes online.

Note that before commit cd14ef54d2 ("igb: Change to use statically
allocated array for MSIx entries"), this problem did not cause oops
but just made the number of queues become 1 because of entering msi_only
mode in igb_set_interrupt_capability().

Fixes: 907b783579 ("igb: Add ethtool support to configure number of channels")
CC: stable <stable@vger.kernel.org>
Signed-off-by: Shota Suzuki <suzuki_shota_t3@lab.ntt.co.jp>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:08 -04:00
Larry Finger
e936a4c6e2 rtlwifi: rtl8821ae: Fix an expression that is always false
[ Upstream commit 251086f588 ]

In routine _rtl8821ae_set_media_status(), an incorrect mask results in a test
for AP status to always be false. Similar bugs were fixed in rtl8192cu and
rtl8192de, but this instance was missed at that time.

Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org> [3.18+]
Cc: David Binderman <dcb314@hotmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:07 -04:00
Andy Lutomirski
4bc532d842 x86/nmi/64: Use DF to avoid userspace RSP confusing nested NMI detection
[ Upstream commit 810bc075f7 ]

We have a tricky bug in the nested NMI code: if we see RSP
pointing to the NMI stack on NMI entry from kernel mode, we
assume that we are executing a nested NMI.

This isn't quite true.  A malicious userspace program can point
RSP at the NMI stack, issue SYSCALL, and arrange for an NMI to
happen while RSP is still pointing at the NMI stack.

Fix it with a sneaky trick.  Set DF in the region of code that
the RSP check is intended to detect.  IRET will clear DF
atomically.

( Note: other than paravirt, there's little need for all this
  complexity. We could check RIP instead of RSP. )

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:07 -04:00
Andy Lutomirski
eb0bad52bb x86/nmi/64: Reorder nested NMI checks
[ Upstream commit a27507ca2d ]

Check the repeat_nmi .. end_repeat_nmi special case first.  The
next patch will rework the RSP check and, as a side effect, the
RSP check will no longer detect repeat_nmi .. end_repeat_nmi, so
we'll need this ordering of the checks.

Note: this is more subtle than it appears.  The check for
repeat_nmi .. end_repeat_nmi jumps straight out of the NMI code
instead of adjusting the "iret" frame to force a repeat.  This
is necessary, because the code between repeat_nmi and
end_repeat_nmi sets "NMI executing" and then writes to the
"iret" frame itself.  If a nested NMI comes in and modifies the
"iret" frame while repeat_nmi is also modifying it, we'll end up
with garbage.  The old code got this right, as does the new
code, but the new code is a bit more explicit.

If we were to move the check right after the "NMI executing"
check, then we'd get it wrong and have random crashes.

( Because the "NMI executing" check would jump to the code that would
  modify the "iret" frame without checking if the interrupted NMI was
  currently modifying it. )

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:06 -04:00
Andy Lutomirski
092f7a2aee x86/nmi/64: Improve nested NMI comments
[ Upstream commit 0b22930eba ]

I found the nested NMI documentation to be difficult to follow.
Improve the comments.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:05 -04:00
Ivan Vecera
5e4c0ae951 bna: fix interrupts storm caused by erroneous packets
[ Upstream commit ade4dc3e61 ]

The commit "e29aa33 bna: Enable Multi Buffer RX" moved packets counter
increment from the beginning of the NAPI processing loop after the check
for erroneous packets so they are never accounted. This counter is used
to inform firmware about number of processed completions (packets).
As these packets are never acked the firmware fires IRQs for them again
and again.

Fixes: e29aa33 ("bna: Enable Multi Buffer RX")
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Acked-by: Rasesh Mody <rasesh.mody@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:05 -04:00
Eric Dumazet
2ab4f1137e udp: fix dst races with multicast early demux
[ Upstream commit 10e2eb878f ]

Multicast dst are not cached. They carry DST_NOCACHE.

As mentioned in commit f886497212 ("ipv4: fix dst race in
sk_dst_get()"), these dst need special care before caching them
into a socket.

Caching them is allowed only if their refcnt was not 0, ie we
must use atomic_inc_not_zero()

Also, we must use READ_ONCE() to fetch sk->sk_rx_dst, as mentioned
in commit d0c294c53a ("tcp: prevent fetching dst twice in early demux
code")

Fixes: 421b3885bf ("udp: ipv4: Add udp early demux")
Tested-by: Gregory Hoggarth <Gregory.Hoggarth@alliedtelesis.co.nz>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Gregory Hoggarth <Gregory.Hoggarth@alliedtelesis.co.nz>
Reported-by: Alex Gartrell <agartrell@fb.com>
Cc: Michal Kubeček <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:04 -04:00
Lars Westerhoff
f0efe01058 packet: missing dev_put() in packet_do_bind()
[ Upstream commit 158cd4af8d ]

When binding a PF_PACKET socket, the use count of the bound interface is
always increased with dev_hold in dev_get_by_{index,name}.  However,
when rebound with the same protocol and device as in the previous bind
the use count of the interface was not decreased.  Ultimately, this
caused the deletion of the interface to fail with the following message:

unregister_netdevice: waiting for dummy0 to become free. Usage count = 1

This patch moves the dev_put out of the conditional part that was only
executed when either the protocol or device changed on a bind.

Fixes: 902fefb82e ('packet: improve socket create/bind latency in some cases')
Signed-off-by: Lars Westerhoff <lars.westerhoff@newtec.eu>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:04 -04:00
Wilson Kok
71960d66b3 fib_rules: fix fib rule dumps across multiple skbs
[ Upstream commit 41fc014332 ]

dump_rules returns skb length and not error.
But when family == AF_UNSPEC, the caller of dump_rules
assumes that it returns an error. Hence, when family == AF_UNSPEC,
we continue trying to dump on -EMSGSIZE errors resulting in
incorrect dump idx carried between skbs belonging to the same dump.
This results in fib rule dump always only dumping rules that fit
into the first skb.

This patch fixes dump_rules to return error so that we exit correctly
and idx is correctly maintained between skbs that are part of the
same dump.

Signed-off-by: Wilson Kok <wkok@cumulusnetworks.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:03 -04:00
Jesse Gross
ae688bc6a5 openvswitch: Zero flows on allocation.
[ Upstream commit ae5f2fb1d5 ]

When support for megaflows was introduced, OVS needed to start
installing flows with a mask applied to them. Since masking is an
expensive operation, OVS also had an optimization that would only
take the parts of the flow keys that were covered by a non-zero
mask. The values stored in the remaining pieces should not matter
because they are masked out.

While this works fine for the purposes of matching (which must always
look at the mask), serialization to netlink can be problematic. Since
the flow and the mask are serialized separately, the uninitialized
portions of the flow can be encoded with whatever values happen to be
present.

In terms of functionality, this has little effect since these fields
will be masked out by definition. However, it leaks kernel memory to
userspace, which is a potential security vulnerability. It is also
possible that other code paths could look at the masked key and get
uninitialized data, although this does not currently appear to be an
issue in practice.

This removes the mask optimization for flows that are being installed.
This was always intended to be the case as the mask optimizations were
really targetting per-packet flow operations.

Fixes: 03f0d916 ("openvswitch: Mega flow implementation")
Signed-off-by: Jesse Gross <jesse@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:03 -04:00
Marcelo Ricardo Leitner
779c19e0ac sctp: fix race on protocol/netns initialization
[ Upstream commit 8e2d61e0ae ]

Consider sctp module is unloaded and is being requested because an user
is creating a sctp socket.

During initialization, sctp will add the new protocol type and then
initialize pernet subsys:

        status = sctp_v4_protosw_init();
        if (status)
                goto err_protosw_init;

        status = sctp_v6_protosw_init();
        if (status)
                goto err_v6_protosw_init;

        status = register_pernet_subsys(&sctp_net_ops);

The problem is that after those calls to sctp_v{4,6}_protosw_init(), it
is possible for userspace to create SCTP sockets like if the module is
already fully loaded. If that happens, one of the possible effects is
that we will have readers for net->sctp.local_addr_list list earlier
than expected and sctp_net_init() does not take precautions while
dealing with that list, leading to a potential panic but not limited to
that, as sctp_sock_init() will copy a bunch of blank/partially
initialized values from net->sctp.

The race happens like this:

     CPU 0                           |  CPU 1
  socket()                           |
   __sock_create                     | socket()
    inet_create                      |  __sock_create
     list_for_each_entry_rcu(        |
        answer, &inetsw[sock->type], |
        list) {                      |   inet_create
      /* no hits */                  |
     if (unlikely(err)) {            |
      ...                            |
      request_module()               |
      /* socket creation is blocked  |
       * the module is fully loaded  |
       */                            |
       sctp_init                     |
        sctp_v4_protosw_init         |
         inet_register_protosw       |
          list_add_rcu(&p->list,     |
                       last_perm);   |
                                     |  list_for_each_entry_rcu(
                                     |     answer, &inetsw[sock->type],
        sctp_v6_protosw_init         |     list) {
                                     |     /* hit, so assumes protocol
                                     |      * is already loaded
                                     |      */
                                     |  /* socket creation continues
                                     |   * before netns is initialized
                                     |   */
        register_pernet_subsys       |

Simply inverting the initialization order between
register_pernet_subsys() and sctp_v4_protosw_init() is not possible
because register_pernet_subsys() will create a control sctp socket, so
the protocol must be already visible by then. Deferring the socket
creation to a work-queue is not good specially because we loose the
ability to handle its errors.

So, as suggested by Vlad, the fix is to split netns initialization in
two moments: defaults and control socket, so that the defaults are
already loaded by when we register the protocol, while control socket
initialization is kept at the same moment it is today.

Fixes: 4db67e8086 ("sctp: Make the address lists per network namespace")
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:02 -04:00
Daniel Borkmann
d38200098e netlink, mmap: transform mmap skb into full skb on taps
[ Upstream commit 1853c94964 ]

Ken-ichirou reported that running netlink in mmap mode for receive in
combination with nlmon will throw a NULL pointer dereference in
__kfree_skb() on nlmon_xmit(), in my case I can also trigger an "unable
to handle kernel paging request". The problem is the skb_clone() in
__netlink_deliver_tap_skb() for skbs that are mmaped.

I.e. the cloned skb doesn't have a destructor, whereas the mmap netlink
skb has it pointed to netlink_skb_destructor(), set in the handler
netlink_ring_setup_skb(). There, skb->head is being set to NULL, so
that in such cases, __kfree_skb() doesn't perform a skb_release_data()
via skb_release_all(), where skb->head is possibly being freed through
kfree(head) into slab allocator, although netlink mmap skb->head points
to the mmap buffer. Similarly, the same has to be done also for large
netlink skbs where the data area is vmalloced. Therefore, as discussed,
make a copy for these rather rare cases for now. This fixes the issue
on my and Ken-ichirou's test-cases.

Reference: http://thread.gmane.org/gmane.linux.network/371129
Fixes: bcbde0d449 ("net: netlink: virtual tap device management")
Reported-by: Ken-ichirou MATSUZAWA <chamaken@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Ken-ichirou MATSUZAWA <chamaken@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:01 -04:00
Richard Laing
3ad45f92f8 net/ipv6: Correct PIM6 mrt_lock handling
[ Upstream commit 25b4a44c19 ]

In the IPv6 multicast routing code the mrt_lock was not being released
correctly in the MFC iterator, as a result adding or deleting a MIF would
cause a hang because the mrt_lock could not be acquired.

This fix is a copy of the code for the IPv4 case and ensures that the lock
is released correctly.

Signed-off-by: Richard Laing <richard.laing@alliedtelesis.co.nz>
Acked-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:01 -04:00
Daniel Borkmann
833db3b898 ipv6: fix exthdrs offload registration in out_rt path
[ Upstream commit e41b0bedba ]

We previously register IPPROTO_ROUTING offload under inet6_add_offload(),
but in error path, we try to unregister it with inet_del_offload(). This
doesn't seem correct, it should actually be inet6_del_offload(), also
ipv6_exthdrs_offload_exit() from that commit seems rather incorrect (it
also uses rthdr_offload twice), but it got removed entirely later on.

Fixes: 3336288a9f ("ipv6: Switch to using new offload infrastructure.")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:00 -04:00
Eugene Shatokhin
965360dee1 usbnet: Get EVENT_NO_RUNTIME_PM bit before it is cleared
[ Upstream commit f50791ac1a ]

It is needed to check EVENT_NO_RUNTIME_PM bit of dev->flags in
usbnet_stop(), but its value should be read before it is cleared
when dev->flags is set to 0.

The problem was spotted and the fix was provided by
Oliver Neukum <oneukum@suse.de>.

Signed-off-by: Eugene Shatokhin <eugene.shatokhin@rosalab.ru>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:33:00 -04:00
huaibin Wang
adda5e3536 ip6_gre: release cached dst on tunnel removal
[ Upstream commit d4257295ba ]

When a tunnel is deleted, the cached dst entry should be released.

This problem may prevent the removal of a netns (seen with a x-netns IPv6
gre tunnel):
  unregister_netdevice: waiting for lo to become free. Usage count = 3

CC: Dmitry Kozlov <xeb@mail.ru>
Fixes: c12b395a46 ("gre: Support GRE over IPv6")
Signed-off-by: huaibin Wang <huaibin.wang@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:32:59 -04:00
Daniel Borkmann
2fb9a494b9 rtnetlink: verify IFLA_VF_INFO attributes before passing them to driver
[ Upstream commit 4f7d2cdfdd ]

Jason Gunthorpe reported that since commit c02db8c629 ("rtnetlink: make
SR-IOV VF interface symmetric"), we don't verify IFLA_VF_INFO attributes
anymore with respect to their policy, that is, ifla_vfinfo_policy[].

Before, they were part of ifla_policy[], but they have been nested since
placed under IFLA_VFINFO_LIST, that contains the attribute IFLA_VF_INFO,
which is another nested attribute for the actual VF attributes such as
IFLA_VF_MAC, IFLA_VF_VLAN, etc.

Despite the policy being split out from ifla_policy[] in this commit,
it's never applied anywhere. nla_for_each_nested() only does basic nla_ok()
testing for struct nlattr, but it doesn't know about the data context and
their requirements.

Fix, on top of Jason's initial work, does 1) parsing of the attributes
with the right policy, and 2) using the resulting parsed attribute table
from 1) instead of the nla_for_each_nested() loop (just like we used to
do when still part of ifla_policy[]).

Reference: http://thread.gmane.org/gmane.linux.network/368913
Fixes: c02db8c629 ("rtnetlink: make SR-IOV VF interface symmetric")
Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Sucheta Chakraborty <sucheta.chakraborty@qlogic.com>
Cc: Greg Rose <gregory.v.rose@intel.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Rony Efraim <ronye@mellanox.com>
Cc: Vlad Zolotarov <vladz@cloudius-systems.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:32:53 -04:00
Vlad Zolotarov
e8d18053d7 if_link: Add an additional parameter to ifla_vf_info for RSS querying
[ Upstream commit 01a3d79681 ]

Add configuration setting for drivers to allow/block an RSS Redirection
Table and a Hash Key querying for discrete VFs.

On some devices VF share the mentioned above information with PF and
querying it may adduce a theoretical security risk. We want to let a
system administrator to decide if he/she wants to take this risk or not.

Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27 09:31:42 -04:00
Hin-Tak Leung
2b1aeac035 hfs,hfsplus: cache pages correctly between bnode_create and bnode_free
[ Upstream commit 7cb74be6fd ]

Pages looked up by __hfs_bnode_create() (called by hfs_bnode_create() and
hfs_bnode_find() for finding or creating pages corresponding to an inode)
are immediately kmap()'ed and used (both read and write) and kunmap()'ed,
and should not be page_cache_release()'ed until hfs_bnode_free().

This patch fixes a problem I first saw in July 2012: merely running "du"
on a large hfsplus-mounted directory a few times on a reasonably loaded
system would get the hfsplus driver all confused and complaining about
B-tree inconsistencies, and generates a "BUG: Bad page state".  Most
recently, I can generate this problem on up-to-date Fedora 22 with shipped
kernel 4.0.5, by running "du /" (="/" + "/home" + "/mnt" + other smaller
mounts) and "du /mnt" simultaneously on two windows, where /mnt is a
lightly-used QEMU VM image of the full Mac OS X 10.9:

$ df -i / /home /mnt
Filesystem                  Inodes   IUsed      IFree IUse% Mounted on
/dev/mapper/fedora-root    3276800  551665    2725135   17% /
/dev/mapper/fedora-home   52879360  716221   52163139    2% /home
/dev/nbd0p2             4294967295 1387818 4293579477    1% /mnt

After applying the patch, I was able to run "du /" (60+ times) and "du
/mnt" (150+ times) continuously and simultaneously for 6+ hours.

There are many reports of the hfsplus driver getting confused under load
and generating "BUG: Bad page state" or other similar issues over the
years.  [1]

The unpatched code [2] has always been wrong since it entered the kernel
tree.  The only reason why it gets away with it is that the
kmap/memcpy/kunmap follow very quickly after the page_cache_release() so
the kernel has not had a chance to reuse the memory for something else,
most of the time.

The current RW driver appears to have followed the design and development
of the earlier read-only hfsplus driver [3], where-by version 0.1 (Dec
2001) had a B-tree node-centric approach to
read_cache_page()/page_cache_release() per bnode_get()/bnode_put(),
migrating towards version 0.2 (June 2002) of caching and releasing pages
per inode extents.  When the current RW code first entered the kernel [2]
in 2005, there was an REF_PAGES conditional (and "//" commented out code)
to switch between B-node centric paging to inode-centric paging.  There
was a mistake with the direction of one of the REF_PAGES conditionals in
__hfs_bnode_create().  In a subsequent "remove debug code" commit [4], the
read_cache_page()/page_cache_release() per bnode_get()/bnode_put() were
removed, but a page_cache_release() was mistakenly left in (propagating
the "REF_PAGES <-> !REF_PAGE" mistake), and the commented-out
page_cache_release() in bnode_release() (which should be spanned by
!REF_PAGES) was never enabled.

References:
[1]:
Michael Fox, Apr 2013
http://www.spinics.net/lists/linux-fsdevel/msg63807.html
("hfsplus volume suddenly inaccessable after 'hfs: recoff %d too large'")

Sasha Levin, Feb 2015
http://lkml.org/lkml/2015/2/20/85 ("use after free")

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/740814
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1027887
https://bugzilla.kernel.org/show_bug.cgi?id=42342
https://bugzilla.kernel.org/show_bug.cgi?id=63841
https://bugzilla.kernel.org/show_bug.cgi?id=78761

[2]:
http://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/\
fs/hfs/bnode.c?id=d1081202f1d0ee35ab0beb490da4b65d4bc763db
commit d1081202f1d0ee35ab0beb490da4b65d4bc763db
Author: Andrew Morton <akpm@osdl.org>
Date:   Wed Feb 25 16:17:36 2004 -0800

    [PATCH] HFS rewrite

http://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/\
fs/hfsplus/bnode.c?id=91556682e0bf004d98a529bf829d339abb98bbbd

commit 91556682e0bf004d98a529bf829d339abb98bbbd
Author: Andrew Morton <akpm@osdl.org>
Date:   Wed Feb 25 16:17:48 2004 -0800

    [PATCH] HFS+ support

[3]:
http://sourceforge.net/projects/linux-hfsplus/

http://sourceforge.net/projects/linux-hfsplus/files/Linux%202.4.x%20patch/hfsplus%200.1/
http://sourceforge.net/projects/linux-hfsplus/files/Linux%202.4.x%20patch/hfsplus%200.2/

http://linux-hfsplus.cvs.sourceforge.net/viewvc/linux-hfsplus/linux/\
fs/hfsplus/bnode.c?r1=1.4&r2=1.5

Date:   Thu Jun 6 09:45:14 2002 +0000
Use buffer cache instead of page cache in bnode.c. Cache inode extents.

[4]:
http://git.kernel.org/cgit/linux/kernel/git/\
stable/linux-stable.git/commit/?id=a5e3985fa014029eb6795664c704953720cc7f7d

commit a5e3985fa0
Author: Roman Zippel <zippel@linux-m68k.org>
Date:   Tue Sep 6 15:18:47 2005 -0700

[PATCH] hfs: remove debug code

Signed-off-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: Sergei Antonov <saproj@gmail.com>
Reviewed-by: Anton Altaparmakov <anton@tuxera.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Sougata Santra <sougata@tuxera.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:23:45 -04:00
Noa Osherovich
a84c256319 IB/mlx4: Use correct SL on AH query under RoCE
[ Upstream commit 5e99b139f1 ]

The mlx4 IB driver implementation for ib_query_ah used a wrong offset
(28 instead of 29) when link type is Ethernet. Fixed to use the correct one.

Fixes: fa417f7b52 ('IB/mlx4: Add support for IBoE')
Signed-off-by: Shani Michaeli <shanim@mellanox.com>
Signed-off-by: Noa Osherovich <noaos@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:23:10 -04:00
Jack Morgenstein
64665b05f6 IB/mlx4: Forbid using sysfs to change RoCE pkeys
[ Upstream commit 2b135db3e8 ]

The pkey mapping for RoCE must remain the default mapping:
VFs:
  virtual index 0 = mapped to real index 0 (0xFFFF)
  All others indices: mapped to a real pkey index containing an
                      invalid pkey.
PF:
  virtual index i = real index i.

Don't allow users to change these mappings using files found in
sysfs.

Fixes: c1e7e46612 ('IB/mlx4: Add iov directory in sysfs under the ib device')
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:22:45 -04:00
Yishai Hadas
edf5a729fd IB/uverbs: Fix race between ib_uverbs_open and remove_one
[ Upstream commit 35d4a0b63d ]

Fixes: 2a72f21226 ("IB/uverbs: Remove dev_table")

Before this commit there was a device look-up table that was protected
by a spin_lock used by ib_uverbs_open and by ib_uverbs_remove_one. When
it was dropped and container_of was used instead, it enabled the race
with remove_one as dev might be freed just after:
dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev) but
before the kref_get.

In addition, this buggy patch added some dead code as
container_of(x,y,z) can never be NULL and so dev can never be NULL.
As a result the comment above ib_uverbs_open saying "the open method
will either immediately run -ENXIO" is wrong as it can never happen.

The solution follows Jason Gunthorpe suggestion from below URL:
https://www.mail-archive.com/linux-rdma@vger.kernel.org/msg25692.html

cdev will hold a kref on the parent (the containing structure,
ib_uverbs_device) and only when that kref is released it is
guaranteed that open will never be called again.

In addition, fixes the active count scheme to use an atomic
not a kref to prevent WARN_ON as pointed by above comment
from Jason.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:22:05 -04:00
Christoph Hellwig
8e75f06a93 IB/uverbs: reject invalid or unknown opcodes
[ Upstream commit b632ffa7ce ]

We have many WR opcodes that are only supported in kernel space
and/or require optional information to be copied into the WR
structure.  Reject all those not explicitly handled so that we
can't pass invalid information to drivers.

Cc: stable@vger.kernel.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:21:25 -04:00
Mike Marciniszyn
b027811d91 IB/qib: Change lkey table allocation to support more MRs
[ Upstream commit d6f1c17e16 ]

The lkey table is allocated with with a get_user_pages() with an
order based on a number of index bits from a module parameter.

The underlying kernel code cannot allocate that many contiguous pages.

There is no reason the underlying memory needs to be physically
contiguous.

This patch:
- switches the allocation/deallocation to vmalloc/vfree
- caps the number of bits to 23 to insure at least 1 generation bit
  o this matches the module parameter description

Cc: stable@vger.kernel.org
Reviewed-by: Vinit Agnihotri <vinit.abhay.agnihotri@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:21:05 -04:00
Hin-Tak Leung
3d7f1ecf1a hfs: fix B-tree corruption after insertion at position 0
[ Upstream commit b4cc0efea4 ]

Fix B-tree corruption when a new record is inserted at position 0 in the
node in hfs_brec_insert().

This is an identical change to the corresponding hfs b-tree code to Sergei
Antonov's "hfsplus: fix B-tree corruption after insertion at position 0",
to keep similar code paths in the hfs and hfsplus drivers in sync, where
appropriate.

Signed-off-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Sergei Antonov <saproj@gmail.com>
Cc: Joe Perches <joe@perches.com>
Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:20:46 -04:00
NeilBrown
9736e5f17b md/raid10: always set reshape_safe when initializing reshape_position.
[ Upstream commit 299b0685e3 ]

'reshape_position' tracks where in the reshape we have reached.
'reshape_safe' tracks where in the reshape we have safely recorded
in the metadata.

These are compared to determine when to update the metadata.
So it is important that reshape_safe is initialised properly.
Currently it isn't.  When starting a reshape from the beginning
it usually has the correct value by luck.  But when reducing the
number of devices in a RAID10, it has the wrong value and this leads
to the metadata not being updated correctly.
This can lead to corruption if the reshape is not allowed to complete.

This patch is suitable for any -stable kernel which supports RAID10
reshape, which is 3.5 and later.

Fixes: 3ea7daa5d7 ("md/raid10: add reshape support")
Cc: stable@vger.kernel.org (v3.5+ please wait for -final to be out for 2 weeks)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:20:14 -04:00
Jialing Fu
21901ab750 mmc: core: fix race condition in mmc_wait_data_done
[ Upstream commit 71f8a4b81d ]

The following panic is captured in ker3.14, but the issue still exists
in latest kernel.
---------------------------------------------------------------------
[   20.738217] c0 3136 (Compiler) Unable to handle kernel NULL pointer dereference
at virtual address 00000578
......
[   20.738499] c0 3136 (Compiler) PC is at _raw_spin_lock_irqsave+0x24/0x60
[   20.738527] c0 3136 (Compiler) LR is at _raw_spin_lock_irqsave+0x20/0x60
[   20.740134] c0 3136 (Compiler) Call trace:
[   20.740165] c0 3136 (Compiler) [<ffffffc0008ee900>] _raw_spin_lock_irqsave+0x24/0x60
[   20.740200] c0 3136 (Compiler) [<ffffffc0000dd024>] __wake_up+0x1c/0x54
[   20.740230] c0 3136 (Compiler) [<ffffffc000639414>] mmc_wait_data_done+0x28/0x34
[   20.740262] c0 3136 (Compiler) [<ffffffc0006391a0>] mmc_request_done+0xa4/0x220
[   20.740314] c0 3136 (Compiler) [<ffffffc000656894>] sdhci_tasklet_finish+0xac/0x264
[   20.740352] c0 3136 (Compiler) [<ffffffc0000a2b58>] tasklet_action+0xa0/0x158
[   20.740382] c0 3136 (Compiler) [<ffffffc0000a2078>] __do_softirq+0x10c/0x2e4
[   20.740411] c0 3136 (Compiler) [<ffffffc0000a24bc>] irq_exit+0x8c/0xc0
[   20.740439] c0 3136 (Compiler) [<ffffffc00008489c>] handle_IRQ+0x48/0xac
[   20.740469] c0 3136 (Compiler) [<ffffffc000081428>] gic_handle_irq+0x38/0x7c
----------------------------------------------------------------------
Because in SMP, "mrq" has race condition between below two paths:
path1: CPU0: <tasklet context>
  static void mmc_wait_data_done(struct mmc_request *mrq)
  {
     mrq->host->context_info.is_done_rcv = true;
     //
     // If CPU0 has just finished "is_done_rcv = true" in path1, and at
     // this moment, IRQ or ICache line missing happens in CPU0.
     // What happens in CPU1 (path2)?
     //
     // If the mmcqd thread in CPU1(path2) hasn't entered to sleep mode:
     // path2 would have chance to break from wait_event_interruptible
     // in mmc_wait_for_data_req_done and continue to run for next
     // mmc_request (mmc_blk_rw_rq_prep).
     //
     // Within mmc_blk_rq_prep, mrq is cleared to 0.
     // If below line still gets host from "mrq" as the result of
     // compiler, the panic happens as we traced.
     wake_up_interruptible(&mrq->host->context_info.wait);
  }

path2: CPU1: <The mmcqd thread runs mmc_queue_thread>
  static int mmc_wait_for_data_req_done(...
  {
     ...
     while (1) {
           wait_event_interruptible(context_info->wait,
                   (context_info->is_done_rcv ||
                    context_info->is_new_req));
     	   static void mmc_blk_rw_rq_prep(...
           {
           ...
           memset(brq, 0, sizeof(struct mmc_blk_request));

This issue happens very coincidentally; however adding mdelay(1) in
mmc_wait_data_done as below could duplicate it easily.

   static void mmc_wait_data_done(struct mmc_request *mrq)
   {
     mrq->host->context_info.is_done_rcv = true;
+    mdelay(1);
     wake_up_interruptible(&mrq->host->context_info.wait);
    }

At runtime, IRQ or ICache line missing may just happen at the same place
of the mdelay(1).

This patch gets the mmc_context_info at the beginning of function, it can
avoid this race condition.

Signed-off-by: Jialing Fu <jlfu@marvell.com>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
Fixes: 2220eedfd7 ("mmc: fix async request mechanism ....")
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:19:43 -04:00
Jann Horn
5068ce153a fs: if a coredump already exists, unlink and recreate with O_EXCL
[ Upstream commit fbb1816942 ]

It was possible for an attacking user to trick root (or another user) into
writing his coredumps into an attacker-readable, pre-existing file using
rename() or link(), causing the disclosure of secret data from the victim
process' virtual memory.  Depending on the configuration, it was also
possible to trick root into overwriting system files with coredumps.  Fix
that issue by never writing coredumps into existing files.

Requirements for the attack:
 - The attack only applies if the victim's process has a nonzero
   RLIMIT_CORE and is dumpable.
 - The attacker can trick the victim into coredumping into an
   attacker-writable directory D, either because the core_pattern is
   relative and the victim's cwd is attacker-writable or because an
   absolute core_pattern pointing to a world-writable directory is used.
 - The attacker has one of these:
  A: on a system with protected_hardlinks=0:
     execute access to a folder containing a victim-owned,
     attacker-readable file on the same partition as D, and the
     victim-owned file will be deleted before the main part of the attack
     takes place. (In practice, there are lots of files that fulfill
     this condition, e.g. entries in Debian's /var/lib/dpkg/info/.)
     This does not apply to most Linux systems because most distros set
     protected_hardlinks=1.
  B: on a system with protected_hardlinks=1:
     execute access to a folder containing a victim-owned,
     attacker-readable and attacker-writable file on the same partition
     as D, and the victim-owned file will be deleted before the main part
     of the attack takes place.
     (This seems to be uncommon.)
  C: on any system, independent of protected_hardlinks:
     write access to a non-sticky folder containing a victim-owned,
     attacker-readable file on the same partition as D
     (This seems to be uncommon.)

The basic idea is that the attacker moves the victim-owned file to where
he expects the victim process to dump its core.  The victim process dumps
its core into the existing file, and the attacker reads the coredump from
it.

If the attacker can't move the file because he does not have write access
to the containing directory, he can instead link the file to a directory
he controls, then wait for the original link to the file to be deleted
(because the kernel checks that the link count of the corefile is 1).

A less reliable variant that requires D to be non-sticky works with link()
and does not require deletion of the original link: link() the file into
D, but then unlink() it directly before the kernel performs the link count
check.

On systems with protected_hardlinks=0, this variant allows an attacker to
not only gain information from coredumps, but also clobber existing,
victim-writable files with coredumps.  (This could theoretically lead to a
privilege escalation.)

Signed-off-by: Jann Horn <jann@thejh.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:19:16 -04:00
Jaewon Kim
e6064491f5 vmscan: fix increasing nr_isolated incurred by putback unevictable pages
[ Upstream commit c54839a722 ]

reclaim_clean_pages_from_list() assumes that shrink_page_list() returns
number of pages removed from the candidate list.  But shrink_page_list()
puts back mlocked pages without passing it to caller and without
counting as nr_reclaimed.  This increases nr_isolated.

To fix this, this patch changes shrink_page_list() to pass unevictable
pages back to caller.  Caller will take care those pages.

Minchan said:

It fixes two issues.

1. With unevictable page, cma_alloc will be successful.

Exactly speaking, cma_alloc of current kernel will fail due to
unevictable pages.

2. fix leaking of NR_ISOLATED counter of vmstat

With it, too_many_isolated works.  Otherwise, it could make hang until
the process get SIGKILL.

Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:18:57 -04:00
Helge Deller
c9cfe46029 parisc: Filter out spurious interrupts in PA-RISC irq handler
[ Upstream commit b1b4e435e4 ]

When detecting a serial port on newer PA-RISC machines (with iosapic) we have a
long way to go to find the right IRQ line, registering it, then registering the
serial port and the irq handler for the serial port. During this phase spurious
interrupts for the serial port may happen which then crashes the kernel because
the action handler might not have been set up yet.

So, basically it's a race condition between the serial port hardware and the
CPU which sets up the necessary fields in the irq sructs. The main reason for
this race is, that we unmask the serial port irqs too early without having set
up everything properly before (which isn't easily possible because we need the
IRQ number to register the serial ports).

This patch is a work-around for this problem. It adds checks to the CPU irq
handler to verify if the IRQ action field has been initialized already. If not,
we just skip this interrupt (which isn't critical for a serial port at bootup).
The real fix would probably involve rewriting all PA-RISC specific IRQ code
(for CPU, IOSAPIC, GSC and EISA) to use IRQ domains with proper parenting of
the irq chips and proper irq enabling along this line.

This bug has been in the PA-RISC port since the beginning, but the crashes
happened very rarely with currently used hardware.  But on the latest machine
which I bought (a C8000 workstation), which uses the fastest CPUs (4 x PA8900,
1GHz) and which has the largest possible L1 cache size (64MB each), the kernel
crashed at every boot because of this race. So, without this patch the machine
would currently be unuseable.

For the record, here is the flow logic:
1. serial_init_chip() in 8250_gsc.c calls iosapic_serial_irq().
2. iosapic_serial_irq() calls txn_alloc_irq() to find the irq.
3. iosapic_serial_irq() calls cpu_claim_irq() to register the CPU irq
4. cpu_claim_irq() unmasks the CPU irq (which it shouldn't!)
5. serial_init_chip() then registers the 8250 port.
Problems:
- In step 4 the CPU irq shouldn't have been registered yet, but after step 5
- If serial irq happens between 4 and 5 have finished, the kernel will crash

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:18:40 -04:00
John David Anglin
4ea349a739 parisc: Use double word condition in 64bit CAS operation
[ Upstream commit 1b59ddfcf1 ]

The attached change fixes the condition used in the "sub" instruction.
A double word comparison is needed.  This fixes the 64-bit LWS CAS
operation on 64-bit kernels.

I can now enable 64-bit atomic support in GCC.

Cc: <stable@vger.kernel.org>
Signed-off-by: John David Anglin <dave.anglin>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:18:20 -04:00
Trond Myklebust
8c87cb0912 NFS: nfs_set_pgio_error sometimes misses errors
[ Upstream commit e9ae58aeee ]

We should ensure that we always set the pgio_header's error field
if a READ or WRITE RPC call returns an error. The current code depends
on 'hdr->good_bytes' always being initialised to a large value, which
is not always done correctly by callers.
When this happens, applications may end up missing important errors.

Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:18:00 -04:00
Kinglong Mee
7730c1b962 NFS: Fix a NULL pointer dereference of migration recovery ops for v4.2 client
[ Upstream commit 18e3b739fd ]

---Steps to Reproduce--
<nfs-server>
# cat /etc/exports
/nfs/referal  *(rw,insecure,no_subtree_check,no_root_squash,crossmnt)
/nfs/old      *(ro,insecure,subtree_check,root_squash,crossmnt)

<nfs-client>
# mount -t nfs nfs-server:/nfs/ /mnt/
# ll /mnt/*/

<nfs-server>
# cat /etc/exports
/nfs/referal   *(rw,insecure,no_subtree_check,no_root_squash,crossmnt,refer=/nfs/old/@nfs-server)
/nfs/old       *(ro,insecure,subtree_check,root_squash,crossmnt)
# service nfs restart

<nfs-client>
# ll /mnt/*/    --->>>>> oops here

[ 5123.102925] BUG: unable to handle kernel NULL pointer dereference at           (null)
[ 5123.103363] IP: [<ffffffffa03ed38b>] nfs4_proc_get_locations+0x9b/0x120 [nfsv4]
[ 5123.103752] PGD 587b9067 PUD 3cbf5067 PMD 0
[ 5123.104131] Oops: 0000 [#1]
[ 5123.104529] Modules linked in: nfsv4(OE) nfs(OE) fscache(E) nfsd(OE) xfs libcrc32c iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi coretemp crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel ppdev vmw_balloon parport_pc parport i2c_piix4 shpchp auth_rpcgss nfs_acl vmw_vmci lockd grace sunrpc vmwgfx drm_kms_helper ttm drm mptspi serio_raw scsi_transport_spi e1000 mptscsih mptbase ata_generic pata_acpi [last unloaded: nfsd]
[ 5123.105887] CPU: 0 PID: 15853 Comm: ::1-manager Tainted: G           OE   4.2.0-rc6+ #214
[ 5123.106358] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014
[ 5123.106860] task: ffff88007620f300 ti: ffff88005877c000 task.ti: ffff88005877c000
[ 5123.107363] RIP: 0010:[<ffffffffa03ed38b>]  [<ffffffffa03ed38b>] nfs4_proc_get_locations+0x9b/0x120 [nfsv4]
[ 5123.107909] RSP: 0018:ffff88005877fdb8  EFLAGS: 00010246
[ 5123.108435] RAX: ffff880053f3bc00 RBX: ffff88006ce6c908 RCX: ffff880053a0d240
[ 5123.108968] RDX: ffffea0000e6d940 RSI: ffff8800399a0000 RDI: ffff88006ce6c908
[ 5123.109503] RBP: ffff88005877fe28 R08: ffffffff81c708a0 R09: 0000000000000000
[ 5123.110045] R10: 00000000000001a2 R11: ffff88003ba7f5c8 R12: ffff880054c55800
[ 5123.110618] R13: 0000000000000000 R14: ffff880053a0d240 R15: ffff880053a0d240
[ 5123.111169] FS:  0000000000000000(0000) GS:ffffffff81c27000(0000) knlGS:0000000000000000
[ 5123.111726] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5123.112286] CR2: 0000000000000000 CR3: 0000000054cac000 CR4: 00000000001406f0
[ 5123.112888] Stack:
[ 5123.113458]  ffffea0000e6d940 ffff8800399a0000 00000000000167d0 0000000000000000
[ 5123.114049]  0000000000000000 0000000000000000 0000000000000000 00000000a7ec82c6
[ 5123.114662]  ffff88005877fe18 ffffea0000e6d940 ffff8800399a0000 ffff880054c55800
[ 5123.115264] Call Trace:
[ 5123.115868]  [<ffffffffa03fb44b>] nfs4_try_migration+0xbb/0x220 [nfsv4]
[ 5123.116487]  [<ffffffffa03fcb3b>] nfs4_run_state_manager+0x4ab/0x7b0 [nfsv4]
[ 5123.117104]  [<ffffffffa03fc690>] ? nfs4_do_reclaim+0x510/0x510 [nfsv4]
[ 5123.117813]  [<ffffffff810a4527>] kthread+0xd7/0xf0
[ 5123.118456]  [<ffffffff810a4450>] ? kthread_worker_fn+0x160/0x160
[ 5123.119108]  [<ffffffff816d9cdf>] ret_from_fork+0x3f/0x70
[ 5123.119723]  [<ffffffff810a4450>] ? kthread_worker_fn+0x160/0x160
[ 5123.120329] Code: 4c 8b 6a 58 74 17 eb 52 48 8d 55 a8 89 c6 4c 89 e7 e8 4a b5 ff ff 8b 45 b0 85 c0 74 1c 4c 89 f9 48 8b 55 90 48 8b 75 98 48 89 df <41> ff 55 00 3d e8 d8 ff ff 41 89 c6 74 cf 48 8b 4d c8 65 48 33
[ 5123.121643] RIP  [<ffffffffa03ed38b>] nfs4_proc_get_locations+0x9b/0x120 [nfsv4]
[ 5123.122308]  RSP <ffff88005877fdb8>
[ 5123.122942] CR2: 0000000000000000

Fixes: ec011fe847 ("NFS: Introduce a vector of migration recovery ops")
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:17:37 -04:00
NeilBrown
47bd9168e9 NFSv4: don't set SETATTR for O_RDONLY|O_EXCL
[ Upstream commit efcbc04e16 ]

It is unusual to combine the open flags O_RDONLY and O_EXCL, but
it appears that libre-office does just that.

[pid  3250] stat("/home/USER/.config", {st_mode=S_IFDIR|0700, st_size=8192, ...}) = 0
[pid  3250] open("/home/USER/.config/libreoffice/4-suse/user/extensions/buildid", O_RDONLY|O_EXCL <unfinished ...>

NFSv4 takes O_EXCL as a sign that a setattr command should be sent,
probably to reset the timestamps.

When it was an O_RDONLY open, the SETATTR command does not
identify any actual attributes to change.
If no delegation was provided to the open, the SETATTR uses the
all-zeros stateid and the request is accepted (at least by the
Linux NFS server - no harm, no foul).

If a read-delegation was provided, this is used in the SETATTR
request, and a Netapp filer will justifiably claim
NFS4ERR_BAD_STATEID, which the Linux client takes as a sign
to retry - indefinitely.

So only treat O_EXCL specially if O_CREAT was also given.

Signed-off-by: NeilBrown <neilb@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:17:09 -04:00
Filipe Manana
04b4d54f03 Btrfs: check if previous transaction aborted to avoid fs corruption
[ Upstream commit 1f9b8c8fbc ]

While we are committing a transaction, it's possible the previous one is
still finishing its commit and therefore we wait for it to finish first.
However we were not checking if that previous transaction ended up getting
aborted after we waited for it to commit, so we ended up committing the
current transaction which can lead to fs corruption because the new
superblock can point to trees that have had one or more nodes/leafs that
were never durably persisted.
The following sequence diagram exemplifies how this is possible:

          CPU 0                                                        CPU 1

  transaction N starts

  (...)

  btrfs_commit_transaction(N)

    cur_trans->state = TRANS_STATE_COMMIT_START;
    (...)
    cur_trans->state = TRANS_STATE_COMMIT_DOING;
    (...)

    cur_trans->state = TRANS_STATE_UNBLOCKED;
    root->fs_info->running_transaction = NULL;

                                                              btrfs_start_transaction()
                                                                 --> starts transaction N + 1

    btrfs_write_and_wait_transaction(trans, root);
      --> starts writing all new or COWed ebs created
          at transaction N

                                                              creates some new ebs, COWs some
                                                              existing ebs but doesn't COW or
                                                              deletes eb X

                                                              btrfs_commit_transaction(N + 1)
                                                                (...)
                                                                cur_trans->state = TRANS_STATE_COMMIT_START;
                                                                (...)
                                                                wait_for_commit(root, prev_trans);
                                                                  --> prev_trans == transaction N

    btrfs_write_and_wait_transaction() continues
    writing ebs
       --> fails writing eb X, we abort transaction N
           and set bit BTRFS_FS_STATE_ERROR on
           fs_info->fs_state, so no new transactions
           can start after setting that bit

       cleanup_transaction()
         btrfs_cleanup_one_transaction()
           wakes up task at CPU 1

                                                                continues, doesn't abort because
                                                                cur_trans->aborted (transaction N + 1)
                                                                is zero, and no checks for bit
                                                                BTRFS_FS_STATE_ERROR in fs_info->fs_state
                                                                are made

                                                                btrfs_write_and_wait_transaction(trans, root);
                                                                  --> succeeds, no errors during writeback

                                                                write_ctree_super(trans, root, 0);
                                                                  --> succeeds
                                                                  --> we have now a superblock that points us
                                                                      to some root that uses eb X, which was
                                                                      never written to disk

In this scenario future attempts to read eb X from disk results in an
error message like "parent transid verify failed on X wanted Y found Z".

So fix this by aborting the current transaction if after waiting for the
previous transaction we verify that it was aborted.

Cc: stable@vger.kernel.org
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:16:46 -04:00
Sakari Ailus
bf4f105946 [media] v4l: omap3isp: Fix sub-device power management code
[ Upstream commit 9d39f05490 ]

Commit 813f5c0ac5 ("media: Change media device link_notify behaviour")
modified the media controller link setup notification API and updated the
OMAP3 ISP driver accordingly. As a side effect it introduced a bug by
turning power on after setting the link instead of before. This results in
sub-devices not being powered down in some cases when they should be. Fix
it.

Fixes: 813f5c0ac5 [media] media: Change media device link_notify behaviour

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Cc: stable@vger.kernel.org # since v3.10
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07 10:16:30 -04:00