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  1. 03 May, 2017 10 commits
  3. 27 Apr, 2017 25 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.10.13 · b957be36
      Greg Kroah-Hartman authored
      b957be36
    • Dan Williams's avatar
      device-dax: switch to srcu, fix rcu_read_lock() vs pte allocation · 9254ada0
      Dan Williams authored 
      commit 956a4cd2 upstream.

The following warning triggers with a new unit test that stresses the
device-dax interface.

 ===============================
 [ ERR: suspicious RCU usage.  ]
 4.11.0-rc4+ #1049 Tainted: G           O
 -------------------------------
 ./include/linux/rcupdate.h:521 Illegal context switch in RCU read-side critical section!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 0
 2 locks held by fio/9070:
  #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff8d0739d7>] __do_page_fault+0x167/0x4f0
  #1:  (rcu_read_lock){......}, at: [<ffffffffc03fbd02>] dax_dev_huge_fault+0x32/0x620 [dax]

 Call Trace:
  dump_stack+0x86/0xc3
  lockdep_rcu_suspicious+0xd7/0x110
  ___might_sleep+0xac/0x250
  __might_sleep+0x4a/0x80
  __alloc_pages_nodemask+0x23a/0x360
  alloc_pages_current+0xa1/0x1f0
  pte_alloc_one+0x17/0x80
  __pte_alloc+0x1e/0x120
  __get_locked_pte+0x1bf/0x1d0
  insert_pfn.isra.70+0x3a/0x100
  ? lookup_memtype+0xa6/0xd0
  vm_insert_mixed+0x64/0x90
  dax_dev_huge_fault+0x520/0x620 [dax]
  ? dax_dev_huge_fault+0x32/0x620 [dax]
  dax_dev_fault+0x10/0x20 [dax]
  __do_fault+0x1e/0x140
  __handle_mm_fault+0x9af/0x10d0
  handle_mm_fault+0x16d/0x370
  ? handle_mm_fault+0x47/0x370
  __do_page_fault+0x28c/0x4f0
  trace_do_page_fault+0x58/0x2a0
  do_async_page_fault+0x1a/0xa0
  async_page_fault+0x28/0x30

Inserting a page table entry may trigger an allocation while we are
holding a read lock to keep the device instance alive for the duration
of the fault. Use srcu for this keep-alive protection.

Fixes: dee41079 ("/dev/dax, core: file operations and dax-mmap")
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9254ada0
    • Yazen Ghannam's avatar
      x86/mce/AMD: Give a name to MCA bank 3 when accessed with legacy MSRs · 7d1c1be6
      Yazen Ghannam authored 
      commit 29f72ce3 upstream.

MCA bank 3 is reserved on systems pre-Fam17h, so it didn't have a name.
However, MCA bank 3 is defined on Fam17h systems and can be accessed
using legacy MSRs. Without a name we get a stack trace on Fam17h systems
when trying to register sysfs files for bank 3 on kernels that don't
recognize Scalable MCA.

Call MCA bank 3 "decode_unit" since this is what it represents on
Fam17h. This will allow kernels without SMCA support to see this bank on
Fam17h+ and prevent the stack trace. This will not affect older systems
since this bank is reserved on them, i.e. it'll be ignored.

Tested on AMD Fam15h and Fam17h systems.

  WARNING: CPU: 26 PID: 1 at lib/kobject.c:210 kobject_add_internal
  kobject: (ffff88085bb256c0): attempted to be registered with empty name!
  ...
  Call Trace:
   kobject_add_internal
   kobject_add
   kobject_create_and_add
   threshold_create_device
   threshold_init_device
Signed-off-by: default avatarYazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1490102285-3659-1-git-send-email-Yazen.Ghannam@amd.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7d1c1be6
    • Ravi Bangoria's avatar
      powerpc/kprobe: Fix oops when kprobed on 'stdu' instruction · 1136723a
      Ravi Bangoria authored 
      commit 9e1ba4f2 upstream.

If we set a kprobe on a 'stdu' instruction on powerpc64, we see a kernel
OOPS:

  Bad kernel stack pointer cd93c840 at c000000000009868
  Oops: Bad kernel stack pointer, sig: 6 [#1]
  ...
  GPR00: c000001fcd93cb30 00000000cd93c840 c0000000015c5e00 00000000cd93c840
  ...
  NIP [c000000000009868] resume_kernel+0x2c/0x58
  LR [c000000000006208] program_check_common+0x108/0x180

On a 64-bit system when the user probes on a 'stdu' instruction, the kernel does
not emulate actual store in emulate_step() because it may corrupt the exception
frame. So the kernel does the actual store operation in exception return code
i.e. resume_kernel().

resume_kernel() loads the saved stack pointer from memory using lwz, which only
loads the low 32-bits of the address, causing the kernel crash.

Fix this by loading the 64-bit value instead.

Fixes: be96f633 ("powerpc: Split out instruction analysis part of emulate_step()")
Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Reviewed-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: default avatarAnanth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
[mpe: Change log massage, add stable tag]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1136723a
    • Sebastian Siewior's avatar
      ubi/upd: Always flush after prepared for an update · a6db4334
      Sebastian Siewior authored 
      commit 9cd9a21c upstream.

In commit 6afaf8a4 ("UBI: flush wl before clearing update marker") I
managed to trigger and fix a similar bug. Now here is another version of
which I assumed it wouldn't matter back then but it turns out UBI has a
check for it and will error out like this:

|ubi0 warning: validate_vid_hdr: inconsistent used_ebs
|ubi0 error: validate_vid_hdr: inconsistent VID header at PEB 592

All you need to trigger this is? "ubiupdatevol /dev/ubi0_0 file" + a
powercut in the middle of the operation.
ubi_start_update() sets the update-marker and puts all EBs on the erase
list. After that userland can proceed to write new data while the old EB
aren't erased completely. A powercut at this point is usually not that
much of a tragedy. UBI won't give read access to the static volume
because it has the update marker. It will most likely set the corrupted
flag because it misses some EBs.
So we are all good. Unless the size of the image that has been written
differs from the old image in the magnitude of at least one EB. In that
case UBI will find two different values for `used_ebs' and refuse to
attach the image with the error message mentioned above.

So in order not to get in the situation, the patch will ensure that we
wait until everything is removed before it tries to write any data.
The alternative would be to detect such a case and remove all EBs at the
attached time after we processed the volume-table and see the
update-marker set. The patch looks bigger and I doubt it is worth it
since usually the write() will wait from time to time for a new EB since
usually there not that many spare EB that can be used.
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a6db4334
    • Vishal Verma's avatar
      x86/mce: Make the MCE notifier a blocking one · a32ff3f0
      Vishal Verma authored 
      commit 0dc9c639 upstream.

The NFIT MCE handler callback (for handling media errors on NVDIMMs)
takes a mutex to add the location of a memory error to a list. But since
the notifier call chain for machine checks (x86_mce_decoder_chain) is
atomic, we get a lockdep splat like:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
  in_atomic(): 1, irqs_disabled(): 0, pid: 4, name: kworker/0:0
  [..]
  Call Trace:
   dump_stack
   ___might_sleep
   __might_sleep
   mutex_lock_nested
   ? __lock_acquire
   nfit_handle_mce
   notifier_call_chain
   atomic_notifier_call_chain
   ? atomic_notifier_call_chain
   mce_gen_pool_process

Convert the notifier to a blocking one which gets to run only in process
context.

Boris: remove the notifier call in atomic context in print_mce(). For
now, let's print the MCE on the atomic path so that we can make sure
they go out and get logged at least.

Fixes: 6839a6d9 ("nfit: do an ARS scrub on hitting a latent media error")
Reported-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: default avatarVishal Verma <vishal.l.verma@intel.com>
Acked-by: default avatarTony Luck <tony.luck@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20170411224457.24777-1-vishal.l.verma@intel.comSigned-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a32ff3f0
    • Johannes Berg's avatar
      mac80211: fix MU-MIMO follow-MAC mode · c77e7d37
      Johannes Berg authored 
      commit 9e478066 upstream.

There are two bugs in the follow-MAC code:
 * it treats the radiotap header as the 802.11 header
   (therefore it can't possibly work)
 * it doesn't verify that the skb data it accesses is actually
   present in the header, which is mitigated by the first point

Fix this by moving all of this out into a separate function.
This function copies the data it needs using skb_copy_bits()
to make sure it can be accessed if it's paged, and offsets
that by the possibly present vendor radiotap header.

This also makes all those conditions more readable.
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c77e7d37
    • Johannes Berg's avatar
      mac80211: reject ToDS broadcast data frames · ee9b4899
      Johannes Berg authored 
      commit 3018e947 upstream.

AP/AP_VLAN modes don't accept any real 802.11 multicast data
frames, but since they do need to accept broadcast management
frames the same is currently permitted for data frames. This
opens a security problem because such frames would be decrypted
with the GTK, and could even contain unicast L3 frames.

Since the spec says that ToDS frames must always have the BSSID
as the RA (addr1), reject any other data frames.

The problem was originally reported in "Predicting, Decrypting,
and Abusing WPA2/802.11 Group Keys" at usenix
https://www.usenix.org/conference/usenixsecurity16/technical-sessions/presentation/vanhoef
and brought to my attention by Jouni.
Reported-by: default avatarJouni Malinen <j@w1.fi>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
--
      ee9b4899
    • Richard Weinberger's avatar
      ubifs: Fix O_TMPFILE corner case in ubifs_link() · 71a3e367
      Richard Weinberger authored 
      commit 32fe905c upstream.

It is perfectly fine to link a tmpfile back using linkat().
Since tmpfiles are created with a link count of 0 they appear
on the orphan list, upon re-linking the inode has to be removed
from the orphan list again.

Ralph faced a filesystem corruption in combination with overlayfs
due to this bug.

Cc: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Reported-by: default avatarRalph Sennhauser <ralph.sennhauser@gmail.com>
Tested-by: default avatarRalph Sennhauser <ralph.sennhauser@gmail.com>
Reported-by: default avatarAmir Goldstein <amir73il@gmail.com>
Fixes: 474b9370 ("ubifs: Implement O_TMPFILE")
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      71a3e367
    • Felix Fietkau's avatar
      ubifs: Fix RENAME_WHITEOUT support · c1cadf6a
      Felix Fietkau authored 
      commit c3d9fda6 upstream.

Remove faulty leftover check in do_rename(), apparently introduced in a
merge that combined whiteout support changes with commit f03b8ad8
("fs: support RENAME_NOREPLACE for local filesystems")

Fixes: f03b8ad8 ("fs: support RENAME_NOREPLACE for local filesystems")
Fixes: 9e0a1fff ("ubifs: Implement RENAME_WHITEOUT")
Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c1cadf6a
    • Haibo Chen's avatar
      mmc: sdhci-esdhc-imx: increase the pad I/O drive strength for DDR50 card · 27456652
      Haibo Chen authored 
      commit 9f327845 upstream.

Currently for DDR50 card, it need tuning in default. We meet tuning fail
issue for DDR50 card and some data CRC error when DDR50 sd card works.

This is because the default pad I/O drive strength can't make sure DDR50
card work stable. So increase the pad I/O drive strength for DDR50 card,
and use pins_100mhz.

This fixes DDR50 card support for IMX since DDR50 tuning was enabled from
commit 9faac7b9 ("mmc: sdhci: enable tuning for DDR50")
Tested-and-reported-by: default avatarTim Harvey <tharvey@gateworks.com>
Signed-off-by: default avatarHaibo Chen <haibo.chen@nxp.com>
Acked-by: default avatarDong Aisheng <aisheng.dong@nxp.com>
Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      27456652
    • Douglas Anderson's avatar
      mmc: dw_mmc: Don't allow Runtime PM for SDIO cards · b478c19f
      Douglas Anderson authored 
      commit a6db2c86 upstream.

According to the SDIO standard interrupts are normally signalled in a
very complicated way.  They require the card clock to be running and
require the controller to be paying close attention to the signals
coming from the card.  This simply can't happen with the clock stopped
or with the controller in a low power mode.

To that end, we'll disable runtime_pm when we detect that an SDIO card
was inserted.  This is much like with what we do with the special
"SDMMC_CLKEN_LOW_PWR" bit that dw_mmc supports.

NOTE: we specifically do this Runtime PM disabling at card init time
rather than in the enable_sdio_irq() callback.  This is _different_
than how SDHCI does it.  Why do we do it differently?

- Unlike SDHCI, dw_mmc uses the standard sdio_irq code in Linux (AKA
  dw_mmc doesn't set MMC_CAP2_SDIO_IRQ_NOTHREAD).
- Because we use the standard sdio_irq code:
  - We see a constant stream of enable_sdio_irq(0) and
    enable_sdio_irq(1) calls.  This is because the standard code
    disables interrupts while processing and re-enables them after.
  - While interrupts are disabled, there's technically a period where
    we could get runtime disabled while processing interrupts.
  - If we are runtime disabled while processing interrupts, we'll
    reset the controller at resume time (see dw_mci_runtime_resume),
    which seems like a terrible idea because we could possibly have
    another interrupt pending.

To fix the above isues we'd want to put something in the standard
sdio_irq code that makes sure to call pm_runtime get/put when
interrupts are being actively being processed.  That's possible to do,
but it seems like a more complicated mechanism when we really just
want the runtime pm disabled always for SDIO cards given that all the
other bits needed to get Runtime PM vs. SDIO just aren't there.

NOTE: at some point in time someone might come up with a fancy way to
do SDIO interrupts and still allow (some) amount of runtime PM.
Technically we could turn off the card clock if we used an alternate
way of signaling SDIO interrupts (and out of band interrupt is one way
to do this).  We probably wouldn't actually want to fully runtime
suspend in this case though--at least not with the current
dw_mci_runtime_resume() which basically fully resets the controller at
resume time.

Fixes: e9ed8835 ("mmc: dw_mmc: add runtime PM callback")
Reported-by: default avatarBrian Norris <briannorris@chromium.org>
Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
Acked-by: default avatarJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: default avatarShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b478c19f
    • Arnd Bergmann's avatar
      ACPI / power: Avoid maybe-uninitialized warning · 9b02ecd1
      Arnd Bergmann authored 
      commit fe8c470a upstream.

gcc -O2 cannot always prove that the loop in acpi_power_get_inferred_state()
is enterered at least once, so it assumes that cur_state might not get
initialized:

drivers/acpi/power.c: In function 'acpi_power_get_inferred_state':
drivers/acpi/power.c:222:9: error: 'cur_state' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This sets the variable to zero at the start of the loop, to ensure that
there is well-defined behavior even for an empty list. This gets rid of
the warning.

The warning first showed up when the -Os flag got removed in a bug fix
patch in linux-4.11-rc5.

I would suggest merging this addon patch on top of that bug fix to avoid
introducing a new warning in the stable kernels.

Fixes: 61b79e16 (ACPI: Fix incompatibility with mcount-based function graph tracing)
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9b02ecd1
    • Thorsten Leemhuis's avatar
      Input: elantech - add Fujitsu Lifebook E547 to force crc_enabled · 7010e15d
      Thorsten Leemhuis authored 
      commit 704de489 upstream.

Temporary got a Lifebook E547 into my hands and noticed the touchpad
only works after running:

	echo "1" > /sys/devices/platform/i8042/serio2/crc_enabled

Add it to the list of machines that need this workaround.
Signed-off-by: default avatarThorsten Leemhuis <linux@leemhuis.info>
Reviewed-by: default avatarUlrik De Bie <ulrik.debie-os@e2big.org>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7010e15d
    • Christian Borntraeger's avatar
      s390/mm: fix CMMA vs KSM vs others · 0cb760df
      Christian Borntraeger authored 
      commit a8f60d1f upstream.

On heavy paging with KSM I see guest data corruption. Turns out that
KSM will add pages to its tree, where the mapping return true for
pte_unused (or might become as such later).  KSM will unmap such pages
and reinstantiate with different attributes (e.g. write protected or
special, e.g. in replace_page or write_protect_page)). This uncovered
a bug in our pagetable handling: We must remove the unused flag as
soon as an entry becomes present again.
Signed-of-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0cb760df
    • Shawn Lin's avatar
      mmc: dw_mmc: silent verbose log when calling from PM context · 71766b91
      Shawn Lin authored 
      commit ce69e2fe upstream.

When deploying runtime PM, it's quite verbose to print the
log of ios setting. Also it's useless to print it from system
PM as it should be the same with booting time. We also have
sysfs to get all these information from ios attribute, so let's
skip this print from PM context.
Signed-off-by: default avatarShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: default avatarJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Cc: Alexander Kochetkov <al.kochet@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      71766b91
    • Germano Percossi's avatar
      CIFS: remove bad_network_name flag · 9f829677
      Germano Percossi authored 
      commit a0918f1c upstream.

STATUS_BAD_NETWORK_NAME can be received during node failover,
causing the flag to be set and making the reconnect thread
always unsuccessful, thereafter.

Once the only place where it is set is removed, the remaining
bits are rendered moot.

Removing it does not prevent "mount" from failing when a non
existent share is passed.

What happens when the share really ceases to exist while the
share is mounted is undefined now as much as it was before.
Signed-off-by: default avatarGermano Percossi <germano.percossi@citrix.com>
Reviewed-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9f829677
    • Sachin Prabhu's avatar
      cifs: Do not send echoes before Negotiate is complete · 5cd77ebf
      Sachin Prabhu authored 
      commit 62a6cfdd upstream.

commit 4fcd1813 ("Fix reconnect to not defer smb3 session reconnect
long after socket reconnect") added support for Negotiate requests to
be initiated by echo calls.

To avoid delays in calling echo after a reconnect, I added the patch
introduced by the commit b8c60012 ("Call echo service immediately
after socket reconnect").

This has however caused a regression with cifs shares which do not have
support for echo calls to trigger Negotiate requests. On connections
which need to call Negotiation, the echo calls trigger an error which
triggers a reconnect which in turn triggers another echo call. This
results in a loop which is only broken when an operation is performed on
the cifs share. For an idle share, it can DOS a server.

The patch uses the smb_operation can_echo() for cifs so that it is
called only if connection has been already been setup.

kernel bz: 194531
Signed-off-by: default avatarSachin Prabhu <sprabhu@redhat.com>
Tested-by: default avatarJonathan Liu <net147@gmail.com>
Acked-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5cd77ebf
    • Rabin Vincent's avatar
      mm: prevent NR_ISOLATE_* stats from going negative · 63ad4051
      Rabin Vincent authored 
      commit fc280fe8 upstream.

Commit 6afcf8ef ("mm, compaction: fix NR_ISOLATED_* stats for pfn
based migration") moved the dec_node_page_state() call (along with the
page_is_file_cache() call) to after putback_lru_page().

But page_is_file_cache() can change after putback_lru_page() is called,
so it should be called before putback_lru_page(), as it was before that
patch, to prevent NR_ISOLATE_* stats from going negative.

Without this fix, non-CONFIG_SMP kernels end up hanging in the
while(too_many_isolated()) { congestion_wait() } loop in
shrink_active_list() due to the negative stats.

 Mem-Info:
  active_anon:32567 inactive_anon:121 isolated_anon:1
  active_file:6066 inactive_file:6639 isolated_file:4294967295
                                                    ^^^^^^^^^^
  unevictable:0 dirty:115 writeback:0 unstable:0
  slab_reclaimable:2086 slab_unreclaimable:3167
  mapped:3398 shmem:18366 pagetables:1145 bounce:0
  free:1798 free_pcp:13 free_cma:0

Fixes: 6afcf8ef ("mm, compaction: fix NR_ISOLATED_* stats for pfn based migration")
Link: http://lkml.kernel.org/r/1492683865-27549-1-git-send-email-rabin.vincent@axis.comSigned-off-by: default avatarRabin Vincent <rabinv@axis.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Ming Ling <ming.ling@spreadtrum.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      63ad4051
    • Steven Rostedt (VMware)'s avatar
      ring-buffer: Have ring_buffer_iter_empty() return true when empty · 64d25336
      Steven Rostedt (VMware) authored 
      commit 78f7a45d upstream.

I noticed that reading the snapshot file when it is empty no longer gives a
status. It suppose to show the status of the snapshot buffer as well as how
to allocate and use it. For example:

 ># cat snapshot
 # tracer: nop
 #
 #
 # * Snapshot is allocated *
 #
 # Snapshot commands:
 # echo 0 > snapshot : Clears and frees snapshot buffer
 # echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.
 #                      Takes a snapshot of the main buffer.
 # echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)
 #                      (Doesn't have to be '2' works with any number that
 #                       is not a '0' or '1')

But instead it just showed an empty buffer:

 ># cat snapshot
 # tracer: nop
 #
 # entries-in-buffer/entries-written: 0/0   #P:4
 #
 #                              _-----=> irqs-off
 #                             / _----=> need-resched
 #                            | / _---=> hardirq/softirq
 #                            || / _--=> preempt-depth
 #                            ||| /     delay
 #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
 #              | |       |   ||||       |         |

What happened was that it was using the ring_buffer_iter_empty() function to
see if it was empty, and if it was, it showed the status. But that function
was returning false when it was empty. The reason was that the iter header
page was on the reader page, and the reader page was empty, but so was the
buffer itself. The check only tested to see if the iter was on the commit
page, but the commit page was no longer pointing to the reader page, but as
all pages were empty, the buffer is also.

Fixes: 651e22f2 ("ring-buffer: Always reset iterator to reader page")
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      64d25336
    • Jason Gerecke's avatar
      HID: wacom: Treat HID_DG_TOOLSERIALNUMBER as unsigned · eff24861
      Jason Gerecke authored 
      commit 286f3f47 upstream.

Because HID_DG_TOOLSERIALNUMBER doesn't first cast the value recieved from HID
to an unsigned type, sign-extension rules can cause the value of
wacom_wac->serial[0] to inadvertently wind up with all 32 of its highest bits
set if the highest bit of "value" was set.

This can cause problems for Tablet PC devices which use AES sensors and the
xf86-input-wacom userspace driver. It is not uncommon for AES sensors to send a
serial number of '0' while the pen is entering or leaving proximity. The
xf86-input-wacom driver ignores events with a serial number of '0' since it
cannot match them up to an in-use tool.  To ensure the xf86-input-wacom driver
does not ignore the final out-of-proximity event, the kernel does not send
MSC_SERIAL events when the value of wacom_wac->serial[0] is '0'. If the highest
bit of HID_DG_TOOLSERIALNUMBER is set by an in-prox pen which later leaves
proximity and sends a '0' for HID_DG_TOOLSERIALNUMBER, then only the lowest 32
bits of wacom_wac->serial[0] are actually cleared, causing the kernel to send
an MSC_SERIAL event. Since the 'input_event' function takes an 'int' as
argument, only those lowest (now-cleared) 32 bits of wacom_wac->serial[0] are
sent to userspace, causing xf86-input-wacom to ignore the event. If the event
was the final out-of-prox event, then xf86-input-wacom may remain in a state
where it believes the pen is in proximity and refuses to allow other devices
under its control (e.g. the touchscreen) to move the cursor.

It should be noted that EMR devices and devices which use both the
HID_DG_TOOLSERIALNUMBER and WACOM_HID_WD_SERIALHI usages (in that order) would
be immune to this issue. It appears only AES devices are affected.

Fixes: f85c9dc6 ("HID: wacom: generic: Support tool ID and additional tool types")
Signed-off-by: default avatarJason Gerecke <jason.gerecke@wacom.com>
Acked-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      eff24861
    • Steven Rostedt (VMware)'s avatar
      tracing: Allocate the snapshot buffer before enabling probe · 838a281c
      Steven Rostedt (VMware) authored 
      commit df62db5b upstream.

Currently the snapshot trigger enables the probe and then allocates the
snapshot. If the probe triggers before the allocation, it could cause the
snapshot to fail and turn tracing off. It's best to allocate the snapshot
buffer first, and then enable the trigger. If something goes wrong in the
enabling of the trigger, the snapshot buffer is still allocated, but it can
also be freed by the user by writting zero into the snapshot buffer file.

Also add a check of the return status of alloc_snapshot().

Fixes: 77fd5c15 ("tracing: Add snapshot trigger to function probes")
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      838a281c
    • Eric Biggers's avatar
      KEYS: fix keyctl_set_reqkey_keyring() to not leak thread keyrings · 523ae2e9
      Eric Biggers authored 
      commit c9f838d1 upstream.

This fixes CVE-2017-7472.

Running the following program as an unprivileged user exhausts kernel
memory by leaking thread keyrings:

	#include <keyutils.h>

	int main()
	{
		for (;;)
			keyctl_set_reqkey_keyring(KEY_REQKEY_DEFL_THREAD_KEYRING);
	}

Fix it by only creating a new thread keyring if there wasn't one before.
To make things more consistent, make install_thread_keyring_to_cred()
and install_process_keyring_to_cred() both return 0 if the corresponding
keyring is already present.

Fixes: d84f4f99 ("CRED: Inaugurate COW credentials")
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      523ae2e9
    • David Howells's avatar
      KEYS: Change the name of the dead type to ".dead" to prevent user access · cc4f9841
      David Howells authored 
      commit c1644fe0 upstream.

This fixes CVE-2017-6951.

Userspace should not be able to do things with the "dead" key type as it
doesn't have some of the helper functions set upon it that the kernel
needs.  Attempting to use it may cause the kernel to crash.

Fix this by changing the name of the type to ".dead" so that it's rejected
up front on userspace syscalls by key_get_type_from_user().

Though this doesn't seem to affect recent kernels, it does affect older
ones, certainly those prior to:

	commit c06cfb08
	Author: David Howells <dhowells@redhat.com>
	Date:   Tue Sep 16 17:36:06 2014 +0100
	KEYS: Remove key_type::match in favour of overriding default by match_preparse

which went in before 3.18-rc1.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cc4f9841
    • David Howells's avatar
      KEYS: Disallow keyrings beginning with '.' to be joined as session keyrings · 4cbbfd6a
      David Howells authored 
      commit ee8f844e upstream.

This fixes CVE-2016-9604.

Keyrings whose name begin with a '.' are special internal keyrings and so
userspace isn't allowed to create keyrings by this name to prevent
shadowing.  However, the patch that added the guard didn't fix
KEYCTL_JOIN_SESSION_KEYRING.  Not only can that create dot-named keyrings,
it can also subscribe to them as a session keyring if they grant SEARCH
permission to the user.

This, for example, allows a root process to set .builtin_trusted_keys as
its session keyring, at which point it has full access because now the
possessor permissions are added.  This permits root to add extra public
keys, thereby bypassing module verification.

This also affects kexec and IMA.

This can be tested by (as root):

	keyctl session .builtin_trusted_keys
	keyctl add user a a @s
	keyctl list @s

which on my test box gives me:

	2 keys in keyring:
	180010936: ---lswrv     0     0 asymmetric: Build time autogenerated kernel key: ae3d4a31b82daa8e1a75b49dc2bba949fd992a05
	801382539: --alswrv     0     0 user: a


Fix this by rejecting names beginning with a '.' in the keyctl.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarMimi Zohar <zohar@linux.vnet.ibm.com>
cc: linux-ima-devel@lists.sourceforge.net
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4cbbfd6a
  5. 21 Apr, 2017 5 commits
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