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  1. 21 Apr, 2017 3 commits
  3. 20 Apr, 2017 12 commits
  5. 19 Apr, 2017 7 commits
    • Cong Wang's avatar
      nsfs: mark dentry with DCACHE_RCUACCESS · 073c516f
      Cong Wang authored 
      Andrey reported a use-after-free in __ns_get_path():

  spin_lock include/linux/spinlock.h:299 [inline]
  lockref_get_not_dead+0x19/0x80 lib/lockref.c:179
  __ns_get_path+0x197/0x860 fs/nsfs.c:66
  open_related_ns+0xda/0x200 fs/nsfs.c:143
  sock_ioctl+0x39d/0x440 net/socket.c:1001
  vfs_ioctl fs/ioctl.c:45 [inline]
  do_vfs_ioctl+0x1bf/0x1780 fs/ioctl.c:685
  SYSC_ioctl fs/ioctl.c:700 [inline]
  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691

We are under rcu read lock protection at that point:

        rcu_read_lock();
        d = atomic_long_read(&ns->stashed);
        if (!d)
                goto slow;
        dentry = (struct dentry *)d;
        if (!lockref_get_not_dead(&dentry->d_lockref))
                goto slow;
        rcu_read_unlock();

but don't use a proper RCU API on the free path, therefore a parallel
__d_free() could free it at the same time.  We need to mark the stashed
dentry with DCACHE_RCUACCESS so that __d_free() will be called after all
readers leave RCU.

Fixes: e149ed2b ("take the targets of /proc/*/ns/* symlinks to separate fs")
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      073c516f
    • Michal Hocko's avatar
      mm: make mm_percpu_wq non freezable · 80d136e1
      Michal Hocko authored 
      Geert has reported a freeze during PM resume and some additional
debugging has shown that the device_resume worker cannot make a forward
progress because it waits for an event which is stuck waiting in
drain_all_pages:

  INFO: task kworker/u4:0:5 blocked for more than 120 seconds.
        Not tainted 4.11.0-rc7-koelsch-00029-g005882e5-dirty #3476
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  kworker/u4:0    D    0     5      2 0x00000000
  Workqueue: events_unbound async_run_entry_fn
    __schedule
    schedule
    schedule_timeout
    wait_for_common
    dpm_wait_for_superior
    device_resume
    async_resume
    async_run_entry_fn
    process_one_work
    worker_thread
    kthread
  [...]
  bash            D    0  1703   1694 0x00000000
    __schedule
    schedule
    schedule_timeout
    wait_for_common
    flush_work
    drain_all_pages
    start_isolate_page_range
    alloc_contig_range
    cma_alloc
    __alloc_from_contiguous
    cma_allocator_alloc
    __dma_alloc
    arm_dma_alloc
    sh_eth_ring_init
    sh_eth_open
    sh_eth_resume
    dpm_run_callback
    device_resume
    dpm_resume
    dpm_resume_end
    suspend_devices_and_enter
    pm_suspend
    state_store
    kernfs_fop_write
    __vfs_write
    vfs_write
    SyS_write
  [...]
  Showing busy workqueues and worker pools:
  [...]
  workqueue mm_percpu_wq: flags=0xc
    pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=0/0
      delayed: drain_local_pages_wq, vmstat_update
    pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=0/0
      delayed: drain_local_pages_wq BAR(1703), vmstat_update

Tetsuo has properly noted that mm_percpu_wq is created as WQ_FREEZABLE
so it is frozen this early during resume so we are effectively
deadlocked.  Fix this by dropping WQ_FREEZABLE when creating
mm_percpu_wq.  We really want to have it operational all the time.

Fixes: ce612879 ("mm: move pcp and lru-pcp draining into single wq")
Reported-and-tested-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Debugged-by: default avatarTetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      80d136e1
    • Linus Torvalds's avatar
      Merge tag 'backlight-for-v4.11' of git://git.linaro.org/people/daniel.thompson/linux · c4bac97b
      Linus Torvalds authored 
      Pull backlight fix from Daniel Thompson:
 "Normally pull requests for backlight come from Lee Jones (and will
  continue to do so) but the bug fixed here is annoying for few people
  so I'm providing a little holiday cover.

  Fix a single bug in the PWM backlight driver and make it play nice
  with a wider range of GPIO devices. This bug is a regression and was
  independently discovered by Geert Uytterhoevan and Paul Kocialkowski
  (and is tested by both)"

* tag 'backlight-for-v4.11' of git://git.linaro.org/people/daniel.thompson/linux:
  backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction()
      c4bac97b
    • Arnd Bergmann's avatar
      ACPI / power: Avoid maybe-uninitialized warning · fe8c470a
      Arnd Bergmann authored 
      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)
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      fe8c470a
    • Geert Uytterhoeven's avatar
      backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction() · 892c7788
      Geert Uytterhoeven authored 
      Commit 7613c922 ("backlight: pwm_bl: Move the checks for initial
power state to a separate function") not just moved some code, but made
slight changes in semantics.

If a gpiochip doesn't implement the optional .get_direction() callback,
gpiod_get_direction always returns -EINVAL, which is never equal to
GPIOF_DIR_IN, leading to the GPIO not being configured for output.

To avoid this, invert the test and check for not GPIOF_DIR_OUT instead,
like the original code did.

This restores the display on r8a7740/armadillo.

Fixes: 7613c922 ("backlight: pwm_bl: Move the checks for initial power state to a separate function")
Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: default avatarPeter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
      892c7788
    • Steven Rostedt (VMware)'s avatar
      tracing: Allocate the snapshot buffer before enabling probe · df62db5b
      Steven Rostedt (VMware) authored 
      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().

Cc: stable@vger.kernel.org
Fixes: 77fd5c15 ("tracing: Add snapshot trigger to function probes")
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      df62db5b
    • Jason Gerecke's avatar
      HID: wacom: Treat HID_DG_TOOLSERIALNUMBER as unsigned · 286f3f47
      Jason Gerecke authored 
      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")
Cc: stable@vger.kernel.org
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>
      286f3f47
  7. 18 Apr, 2017 15 commits
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc · 005882e5
      Linus Torvalds authored 
      Pull sparc fixes from David Miller:
 "Two Sparc bug fixes from Daniel Jordan and Nitin Gupta"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix hugepage page table free
  sparc64: Use LOCKDEP_SMALL, not PROVE_LOCKING_SMALL
      005882e5
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 40d9018e
      Linus Torvalds authored 
      Pull networking fixes from David Miller:

 1) BPF tail call handling bug fixes from Daniel Borkmann.

 2) Fix allowance of too many rx queues in sfc driver, from Bert
    Kenward.

 3) Non-loopback ipv6 packets claiming src of ::1 should be dropped,
    from Florian Westphal.

 4) Statistics requests on KSZ9031 can crash, fix from Grygorii
    Strashko.

 5) TX ring handling fixes in mediatek driver, from Sean Wang.

 6) ip_ra_control can deadlock, fix lock acquisition ordering to fix,
    from Cong WANG.

 7) Fix use after free in ip_recv_error(), from Willem de Buijn.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  bpf: fix checking xdp_adjust_head on tail calls
  bpf: fix cb access in socket filter programs on tail calls
  ipv6: drop non loopback packets claiming to originate from ::1
  net: ethernet: mediatek: fix inconsistency of port number carried in TXD
  net: ethernet: mediatek: fix inconsistency between TXD and the used buffer
  net: phy: micrel: fix crash when statistic requested for KSZ9031 phy
  net: vrf: Fix setting NLM_F_EXCL flag when adding l3mdev rule
  net: thunderx: Fix set_max_bgx_per_node for 81xx rgx
  net-timestamp: avoid use-after-free in ip_recv_error
  ipv4: fix a deadlock in ip_ra_control
  sfc: limit the number of receive queues
      40d9018e
    • Nitin Gupta's avatar
      sparc64: Fix hugepage page table free · 544f8f93
      Nitin Gupta authored 
      Make sure the start adderess is aligned to PMD_SIZE
boundary when freeing page table backing a hugepage
region. The issue was causing segfaults when a region
backed by 64K pages was unmapped since such a region
is in general not PMD_SIZE aligned.
Signed-off-by: default avatarNitin Gupta <nitin.m.gupta@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      544f8f93
    • Daniel Jordan's avatar
      sparc64: Use LOCKDEP_SMALL, not PROVE_LOCKING_SMALL · 395102db
      Daniel Jordan authored 
      CONFIG_PROVE_LOCKING_SMALL shrinks the memory usage of lockdep so the
kernel text, data, and bss fit in the required 32MB limit, but this
option is not set for every config that enables lockdep.

A 4.10 kernel fails to boot with the console output

    Kernel: Using 8 locked TLB entries for main kernel image.
    hypervisor_tlb_lock[2000000:0:8000000071c007c3:1]: errors with f
    Program terminated

with these config options

    CONFIG_LOCKDEP=y
    CONFIG_LOCK_STAT=y
    CONFIG_PROVE_LOCKING=n

To fix, rename CONFIG_PROVE_LOCKING_SMALL to CONFIG_LOCKDEP_SMALL, and
enable this option with CONFIG_LOCKDEP=y so we get the reduced memory
usage every time lockdep is turned on.

Tested that CONFIG_LOCKDEP_SMALL is set to 'y' if and only if
CONFIG_LOCKDEP is set to 'y'.  When other lockdep-related config options
that select CONFIG_LOCKDEP are enabled (e.g. CONFIG_LOCK_STAT or
CONFIG_PROVE_LOCKING), verified that CONFIG_LOCKDEP_SMALL is also
enabled.

Fixes: e6b5f1be ("config: Adding the new config parameter CONFIG_PROVE_LOCKING_SMALL for sparc")
Signed-off-by: default avatarDaniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: default avatarBabu Moger <babu.moger@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      395102db
    • Douglas Anderson's avatar
      mmc: dw_mmc: Don't allow Runtime PM for SDIO cards · a6db2c86
      Douglas Anderson authored 
      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")
Cc: <stable@vger.kernel.org>
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>
      a6db2c86
    • Thorsten Leemhuis's avatar
      Input: elantech - add Fujitsu Lifebook E547 to force crc_enabled · 704de489
      Thorsten Leemhuis authored 
      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.

Cc: stable@vger.kernel.org
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>
      704de489
    • Linus Torvalds's avatar
      Merge tag 'trace-v4.11-rc5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace · fb5e2154
      Linus Torvalds authored 
      Pull ftrace testcase update from Steven Rostedt:
 "While testing my development branch, without the fix for the pid use
  after free bug, the selftest that Namhyung added triggers it. I
  figured it would be good to add the test for the bug after the fix,
  such that it does not exist without the fix.

  I added another patch that lets the test only test part of the pid
  filtering, and ignores the function-fork (filtering on children as
  well) if the function-fork feature does not exist. This feature is
  added by Namhyung just before he added this test. But since the test
  tests both with and without the feature, it would be good to let it
  not fail if the feature does not exist"

* tag 'trace-v4.11-rc5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  selftests: ftrace: Add check for function-fork before running pid filter test
  selftests: ftrace: Add a testcase for function PID filter
      fb5e2154
    • Heiner Kallweit's avatar
      mmc: sdio: fix alignment issue in struct sdio_func · 5ef1ecf0
      Heiner Kallweit authored 
      Certain 64-bit systems (e.g. Amlogic Meson GX) require buffers to be
used for DMA to be 8-byte-aligned. struct sdio_func has an embedded
small DMA buffer not meeting this requirement.
When testing switching to descriptor chain mode in meson-gx driver
SDIO is broken therefore. Fix this by allocating the small DMA buffer
separately as kmalloc ensures that the returned memory area is
properly aligned for every basic data type.
Signed-off-by: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Tested-by: default avatarHelmut Klein <hgkr.klein@gmail.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      5ef1ecf0
    • Steven Rostedt (VMware)'s avatar
      selftests: ftrace: Add check for function-fork before running pid filter test · 9ed19c76
      Steven Rostedt (VMware) authored 
      Have the func-filter-pid test check for the function-fork option before
testing it. It can still test the pid filtering, but will stop before
testing the function-fork option for children inheriting the pids.
This allows the test to be added before the function-fork feature, but after
a bug fix that triggers one of the bugs the test can cause.

Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      9ed19c76
    • Linus Torvalds's avatar
      Merge tag 'trace-v4.11-rc5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace · 0bad6d7e
      Linus Torvalds authored 
      Pull ftrace fix from Steven Rostedt:
 "Namhyung Kim discovered a use after free bug. It has to do with adding
  a pid filter to function tracing in an instance, and then freeing the
  instance"

* tag 'trace-v4.11-rc5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix function pid filter on instances
      0bad6d7e
    • Linus Torvalds's avatar
      Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 · 5ee4c5a9
      Linus Torvalds authored 
      Pull crypto fixes from Herbert Xu:
 "This fixes the following problems:

   - regression in new XTS/LRW code when used with async crypto

   - long-standing bug in ahash API when used with certain algos

   - bogus memory dereference in async algif_aead with certain algos"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: algif_aead - Fix bogus request dereference in completion function
  crypto: ahash - Fix EINPROGRESS notification callback
  crypto: lrw - Fix use-after-free on EINPROGRESS
  crypto: xts - Fix use-after-free on EINPROGRESS
      5ee4c5a9
    • Namhyung Kim's avatar
      selftests: ftrace: Add a testcase for function PID filter · 093be89a
      Namhyung Kim authored 
      Like event pid filtering test, add function pid filtering test with the
new "function-fork" option.  It also tests it on an instance directory
so that it can verify the bug related pid filtering on instances.

Link: http://lkml.kernel.org/r/20170417024430.21194-5-namhyung@kernel.org

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      093be89a
    • Eric Biggers's avatar
      KEYS: fix keyctl_set_reqkey_keyring() to not leak thread keyrings · c9f838d1
      Eric Biggers authored 
      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")
Cc: stable@vger.kernel.org # 2.6.29+
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      c9f838d1
    • David Howells's avatar
      KEYS: Change the name of the dead type to ".dead" to prevent user access · c1644fe0
      David Howells authored 
      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>
cc: stable@vger.kernel.org
      c1644fe0
    • David Howells's avatar
      KEYS: Disallow keyrings beginning with '.' to be joined as session keyrings · ee8f844e
      David Howells authored 
      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
cc: stable@vger.kernel.org
      ee8f844e
  9. 17 Apr, 2017 3 commits
    • Linus Torvalds's avatar
      Merge branch 'parisc-4.11-5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux · 20bb78f6
      Linus Torvalds authored 
      Pull parisc fix from Helge Deller:
 "One patch which fixes get_user() for 64-bit values on 32-bit kernels.

  Up to now we lost the upper 32-bits of the returned 64-bit value"

* 'parisc-4.11-5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix get_user() for 64-bit value on 32-bit kernel
      20bb78f6
    • Sachin Prabhu's avatar
      cifs: Do not send echoes before Negotiate is complete · 62a6cfdd
      Sachin Prabhu authored 
      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>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      62a6cfdd
    • Namhyung Kim's avatar
      ftrace: Fix function pid filter on instances · d879d0b8
      Namhyung Kim authored 
      When function tracer has a pid filter, it adds a probe to sched_switch
to track if current task can be ignored.  The probe checks the
ftrace_ignore_pid from current tr to filter tasks.  But it misses to
delete the probe when removing an instance so that it can cause a crash
due to the invalid tr pointer (use-after-free).

This is easily reproducible with the following:

  # cd /sys/kernel/debug/tracing
  # mkdir instances/buggy
  # echo $$ > instances/buggy/set_ftrace_pid
  # rmdir instances/buggy

  ============================================================================
  BUG: KASAN: use-after-free in ftrace_filter_pid_sched_switch_probe+0x3d/0x90
  Read of size 8 by task kworker/0:1/17
  CPU: 0 PID: 17 Comm: kworker/0:1 Tainted: G    B           4.11.0-rc3  #198
  Call Trace:
   dump_stack+0x68/0x9f
   kasan_object_err+0x21/0x70
   kasan_report.part.1+0x22b/0x500
   ? ftrace_filter_pid_sched_switch_probe+0x3d/0x90
   kasan_report+0x25/0x30
   __asan_load8+0x5e/0x70
   ftrace_filter_pid_sched_switch_probe+0x3d/0x90
   ? fpid_start+0x130/0x130
   __schedule+0x571/0xce0
   ...

To fix it, use ftrace_clear_pids() to unregister the probe.  As
instance_rmdir() already updated ftrace codes, it can just free the
filter safely.

Link: http://lkml.kernel.org/r/20170417024430.21194-2-namhyung@kernel.org

Fixes: 0c8916c3 ("tracing: Add rmdir to remove multibuffer instances")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      d879d0b8
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