<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/lib, branch v4.9.20</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>swiotlb: Add swiotlb=noforce debug option</title>
<updated>2017-01-26T07:24:44+00:00</updated>
<author>
<name>Geert Uytterhoeven</name>
<email>geert+renesas@glider.be</email>
</author>
<published>2016-12-16T13:28:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=41c6b3e8989e79772a50429d92cf91959bcce96d'/>
<id>41c6b3e8989e79772a50429d92cf91959bcce96d</id>
<content type='text'>
commit fff5d99225107f5f13fe4a9805adc2a1c4b5fb00 upstream.

On architectures like arm64, swiotlb is tied intimately to the core
architecture DMA support. In addition, ZONE_DMA cannot be disabled.

To aid debugging and catch devices not supporting DMA to memory outside
the 32-bit address space, add a kernel command line option
"swiotlb=noforce", which disables the use of bounce buffers.
If specified, trying to map memory that cannot be used with DMA will
fail, and a rate-limited warning will be printed.

Note that io_tlb_nslabs is set to 1, which is the minimal supported
value.

Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit fff5d99225107f5f13fe4a9805adc2a1c4b5fb00 upstream.

On architectures like arm64, swiotlb is tied intimately to the core
architecture DMA support. In addition, ZONE_DMA cannot be disabled.

To aid debugging and catch devices not supporting DMA to memory outside
the 32-bit address space, add a kernel command line option
"swiotlb=noforce", which disables the use of bounce buffers.
If specified, trying to map memory that cannot be used with DMA will
fail, and a rate-limited warning will be printed.

Note that io_tlb_nslabs is set to 1, which is the minimal supported
value.

Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>swiotlb: Convert swiotlb_force from int to enum</title>
<updated>2017-01-26T07:24:44+00:00</updated>
<author>
<name>Geert Uytterhoeven</name>
<email>geert+renesas@glider.be</email>
</author>
<published>2016-12-16T13:28:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1fd1e6cd63143cf5d198a536d875dfc88ce179bc'/>
<id>1fd1e6cd63143cf5d198a536d875dfc88ce179bc</id>
<content type='text'>
commit ae7871be189cb41184f1e05742b4a99e2c59774d upstream.

Convert the flag swiotlb_force from an int to an enum, to prepare for
the advent of more possible values.

Suggested-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit ae7871be189cb41184f1e05742b4a99e2c59774d upstream.

Convert the flag swiotlb_force from an int to an enum, to prepare for
the advent of more possible values.

Suggested-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>fix a fencepost error in pipe_advance()</title>
<updated>2017-01-19T19:18:02+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2017-01-15T00:33:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d06367ac1730ded79aa78307126236bf83af95a3'/>
<id>d06367ac1730ded79aa78307126236bf83af95a3</id>
<content type='text'>
commit b9dc6f65bc5e232d1c05fe34b5daadc7e8bbf1fb upstream.

The logics in pipe_advance() used to release all buffers past the new
position failed in cases when the number of buffers to release was equal
to pipe-&gt;buffers.  If that happened, none of them had been released,
leaving pipe full.  Worse, it was trivial to trigger and we end up with
pipe full of uninitialized pages.  IOW, it's an infoleak.

Reported-by: "Alan J. Wylie" &lt;alan@wylie.me.uk&gt;
Tested-by: "Alan J. Wylie" &lt;alan@wylie.me.uk&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b9dc6f65bc5e232d1c05fe34b5daadc7e8bbf1fb upstream.

The logics in pipe_advance() used to release all buffers past the new
position failed in cases when the number of buffers to release was equal
to pipe-&gt;buffers.  If that happened, none of them had been released,
leaving pipe full.  Worse, it was trivial to trigger and we end up with
pipe full of uninitialized pages.  IOW, it's an infoleak.

Reported-by: "Alan J. Wylie" &lt;alan@wylie.me.uk&gt;
Tested-by: "Alan J. Wylie" &lt;alan@wylie.me.uk&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "radix tree test suite: fix compilation"</title>
<updated>2016-12-09T18:41:42+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-12-09T18:41:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2b41226b39b654a5e20bce5a7332f307fdb9156b'/>
<id>2b41226b39b654a5e20bce5a7332f307fdb9156b</id>
<content type='text'>
This reverts commit 53855d10f4567a0577360b6448d52a863929775b.

It shouldn't have come in yet - it depends on the changes in linux-next
that will come in during the next merge window.  As Matthew Wilcox says,
the test suite is broken with the current state without the revert.

Requested-by: Matthew Wilcox &lt;mawilcox@microsoft.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This reverts commit 53855d10f4567a0577360b6448d52a863929775b.

It shouldn't have come in yet - it depends on the changes in linux-next
that will come in during the next merge window.  As Matthew Wilcox says,
the test suite is broken with the current state without the revert.

Requested-by: Matthew Wilcox &lt;mawilcox@microsoft.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>radix tree test suite: fix compilation</title>
<updated>2016-12-08T01:10:00+00:00</updated>
<author>
<name>Matthew Wilcox</name>
<email>mawilcox@microsoft.com</email>
</author>
<published>2016-12-07T22:44:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=53855d10f4567a0577360b6448d52a863929775b'/>
<id>53855d10f4567a0577360b6448d52a863929775b</id>
<content type='text'>
Patch "lib/radix-tree: Convert to hotplug state machine" breaks the test
suite as it adds a call to cpuhp_setup_state_nocalls() which is not
currently emulated in the test suite.  Add it, and delete the emulation
of the old CPU hotplug mechanism.

Link: http://lkml.kernel.org/r/1480369871-5271-36-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox &lt;mawilcox@microsoft.com&gt;
Tested-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Cc: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Cc: Matthew Wilcox &lt;mawilcox@microsoft.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Patch "lib/radix-tree: Convert to hotplug state machine" breaks the test
suite as it adds a call to cpuhp_setup_state_nocalls() which is not
currently emulated in the test suite.  Add it, and delete the emulation
of the old CPU hotplug mechanism.

Link: http://lkml.kernel.org/r/1480369871-5271-36-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox &lt;mawilcox@microsoft.com&gt;
Tested-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Cc: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Cc: Matthew Wilcox &lt;mawilcox@microsoft.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2016-12-07T19:27:33+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-12-07T19:27:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5b43f97f3f21c42ba738df2797930e32e05d5a25'/>
<id>5b43f97f3f21c42ba738df2797930e32e05d5a25</id>
<content type='text'>
Pull locking fixes from Ingo Molnar:
 "Two rtmutex race fixes (which miraculously never triggered, that we
  know of), plus two lockdep printk formatting regression fixes"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix report formatting
  locking/rtmutex: Use READ_ONCE() in rt_mutex_owner()
  locking/rtmutex: Prevent dequeue vs. unlock race
  locking/selftest: Fix output since KERN_CONT changes
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull locking fixes from Ingo Molnar:
 "Two rtmutex race fixes (which miraculously never triggered, that we
  know of), plus two lockdep printk formatting regression fixes"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix report formatting
  locking/rtmutex: Use READ_ONCE() in rt_mutex_owner()
  locking/rtmutex: Prevent dequeue vs. unlock race
  locking/selftest: Fix output since KERN_CONT changes
</pre>
</div>
</content>
</entry>
<entry>
<title>kasan: support use-after-scope detection</title>
<updated>2016-12-01T00:32:52+00:00</updated>
<author>
<name>Dmitry Vyukov</name>
<email>dvyukov@google.com</email>
</author>
<published>2016-11-30T23:54:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=828347f8f9a558cf1af2faa46387a26564f2ac3e'/>
<id>828347f8f9a558cf1af2faa46387a26564f2ac3e</id>
<content type='text'>
Gcc revision 241896 implements use-after-scope detection.  Will be
available in gcc 7.  Support it in KASAN.

Gcc emits 2 new callbacks to poison/unpoison large stack objects when
they go in/out of scope.  Implement the callbacks and add a test.

[dvyukov@google.com: v3]
  Link: http://lkml.kernel.org/r/1479998292-144502-1-git-send-email-dvyukov@google.com
Link: http://lkml.kernel.org/r/1479226045-145148-1-git-send-email-dvyukov@google.com
Signed-off-by: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Acked-by: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[4.0+]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Gcc revision 241896 implements use-after-scope detection.  Will be
available in gcc 7.  Support it in KASAN.

Gcc emits 2 new callbacks to poison/unpoison large stack objects when
they go in/out of scope.  Implement the callbacks and add a test.

[dvyukov@google.com: v3]
  Link: http://lkml.kernel.org/r/1479998292-144502-1-git-send-email-dvyukov@google.com
Link: http://lkml.kernel.org/r/1479226045-145148-1-git-send-email-dvyukov@google.com
Signed-off-by: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Acked-by: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[4.0+]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>lib/debugobjects: export for use in modules</title>
<updated>2016-12-01T00:32:52+00:00</updated>
<author>
<name>Chris Wilson</name>
<email>chris@chris-wilson.co.uk</email>
</author>
<published>2016-11-30T23:54:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f8ff04e2be0815b34d11a72d08473a383a3c9eb5'/>
<id>f8ff04e2be0815b34d11a72d08473a383a3c9eb5</id>
<content type='text'>
Drivers, or other modules, that use a mixture of objects (especially
objects embedded within other objects) would like to take advantage of
the debugobjects facilities to help catch misuse.  Currently, the
debugobjects interface is only available to builtin drivers and requires
a set of EXPORT_SYMBOL_GPL for use by modules.

I am using the debugobjects in i915.ko to try and catch some invalid
operations on embedded objects.  The problem currently only presents
itself across module unload so forcing i915 to be builtin is not an
option.

Link: http://lkml.kernel.org/r/20161122143039.6433-1-chris@chris-wilson.co.uk
Signed-off-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: "Du, Changbin" &lt;changbin.du@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Drivers, or other modules, that use a mixture of objects (especially
objects embedded within other objects) would like to take advantage of
the debugobjects facilities to help catch misuse.  Currently, the
debugobjects interface is only available to builtin drivers and requires
a set of EXPORT_SYMBOL_GPL for use by modules.

I am using the debugobjects in i915.ko to try and catch some invalid
operations on embedded objects.  The problem currently only presents
itself across module unload so forcing i915 to be builtin is not an
option.

Link: http://lkml.kernel.org/r/20161122143039.6433-1-chris@chris-wilson.co.uk
Signed-off-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: "Du, Changbin" &lt;changbin.du@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/selftest: Fix output since KERN_CONT changes</title>
<updated>2016-11-25T06:12:19+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2016-11-24T22:45:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2513940989fa2c56d0aeb4f5792d22804d92ab4c'/>
<id>2513940989fa2c56d0aeb4f5792d22804d92ab4c</id>
<content type='text'>
Since the KERN_CONT changes the locking-selftest output is messed up, eg:

  ----------------------------------------------------------------------------
                                   | spin |wlock |rlock |mutex | wsem | rsem |
    --------------------------------------------------------------------------
                       A-A deadlock:
    ok  |
    ok  |
    ok  |
    ok  |
    ok  |
    ok  |

Use pr_cont() to get it looking normal again:

  ----------------------------------------------------------------------------
                                   | spin |wlock |rlock |mutex | wsem | rsem |
    --------------------------------------------------------------------------
                       A-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |

Reported-by: Christian Kujau &lt;lists@nerdbynature.de&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/1480027528-934-1-git-send-email-mpe@ellerman.id.au
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since the KERN_CONT changes the locking-selftest output is messed up, eg:

  ----------------------------------------------------------------------------
                                   | spin |wlock |rlock |mutex | wsem | rsem |
    --------------------------------------------------------------------------
                       A-A deadlock:
    ok  |
    ok  |
    ok  |
    ok  |
    ok  |
    ok  |

Use pr_cont() to get it looking normal again:

  ----------------------------------------------------------------------------
                                   | spin |wlock |rlock |mutex | wsem | rsem |
    --------------------------------------------------------------------------
                       A-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |

Reported-by: Christian Kujau &lt;lists@nerdbynature.de&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/1480027528-934-1-git-send-email-mpe@ellerman.id.au
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mpi: Fix NULL ptr dereference in mpi_powm() [ver #3]</title>
<updated>2016-11-25T01:57:50+00:00</updated>
<author>
<name>Andrey Ryabinin</name>
<email>aryabinin@virtuozzo.com</email>
</author>
<published>2016-11-24T13:23:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f5527fffff3f002b0a6b376163613b82f69de073'/>
<id>f5527fffff3f002b0a6b376163613b82f69de073</id>
<content type='text'>
This fixes CVE-2016-8650.

If mpi_powm() is given a zero exponent, it wants to immediately return
either 1 or 0, depending on the modulus.  However, if the result was
initalised with zero limb space, no limbs space is allocated and a
NULL-pointer exception ensues.

Fix this by allocating a minimal amount of limb space for the result when
the 0-exponent case when the result is 1 and not touching the limb space
when the result is 0.

This affects the use of RSA keys and X.509 certificates that carry them.

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [&lt;ffffffff8138ce5d&gt;] mpi_powm+0x32/0x7e6
PGD 0
Oops: 0002 [#1] SMP
Modules linked in:
CPU: 3 PID: 3014 Comm: keyctl Not tainted 4.9.0-rc6-fscache+ #278
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
task: ffff8804011944c0 task.stack: ffff880401294000
RIP: 0010:[&lt;ffffffff8138ce5d&gt;]  [&lt;ffffffff8138ce5d&gt;] mpi_powm+0x32/0x7e6
RSP: 0018:ffff880401297ad8  EFLAGS: 00010212
RAX: 0000000000000000 RBX: ffff88040868bec0 RCX: ffff88040868bba0
RDX: ffff88040868b260 RSI: ffff88040868bec0 RDI: ffff88040868bee0
RBP: ffff880401297ba8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000047 R11: ffffffff8183b210 R12: 0000000000000000
R13: ffff8804087c7600 R14: 000000000000001f R15: ffff880401297c50
FS:  00007f7a7918c700(0000) GS:ffff88041fb80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000401250000 CR4: 00000000001406e0
Stack:
 ffff88040868bec0 0000000000000020 ffff880401297b00 ffffffff81376cd4
 0000000000000100 ffff880401297b10 ffffffff81376d12 ffff880401297b30
 ffffffff81376f37 0000000000000100 0000000000000000 ffff880401297ba8
Call Trace:
 [&lt;ffffffff81376cd4&gt;] ? __sg_page_iter_next+0x43/0x66
 [&lt;ffffffff81376d12&gt;] ? sg_miter_get_next_page+0x1b/0x5d
 [&lt;ffffffff81376f37&gt;] ? sg_miter_next+0x17/0xbd
 [&lt;ffffffff8138ba3a&gt;] ? mpi_read_raw_from_sgl+0xf2/0x146
 [&lt;ffffffff8132a95c&gt;] rsa_verify+0x9d/0xee
 [&lt;ffffffff8132acca&gt;] ? pkcs1pad_sg_set_buf+0x2e/0xbb
 [&lt;ffffffff8132af40&gt;] pkcs1pad_verify+0xc0/0xe1
 [&lt;ffffffff8133cb5e&gt;] public_key_verify_signature+0x1b0/0x228
 [&lt;ffffffff8133d974&gt;] x509_check_for_self_signed+0xa1/0xc4
 [&lt;ffffffff8133cdde&gt;] x509_cert_parse+0x167/0x1a1
 [&lt;ffffffff8133d609&gt;] x509_key_preparse+0x21/0x1a1
 [&lt;ffffffff8133c3d7&gt;] asymmetric_key_preparse+0x34/0x61
 [&lt;ffffffff812fc9f3&gt;] key_create_or_update+0x145/0x399
 [&lt;ffffffff812fe227&gt;] SyS_add_key+0x154/0x19e
 [&lt;ffffffff81001c2b&gt;] do_syscall_64+0x80/0x191
 [&lt;ffffffff816825e4&gt;] entry_SYSCALL64_slow_path+0x25/0x25
Code: 56 41 55 41 54 53 48 81 ec a8 00 00 00 44 8b 71 04 8b 42 04 4c 8b 67 18 45 85 f6 89 45 80 0f 84 b4 06 00 00 85 c0 75 2f 41 ff ce &lt;49&gt; c7 04 24 01 00 00 00 b0 01 75 0b 48 8b 41 18 48 83 38 01 0f
RIP  [&lt;ffffffff8138ce5d&gt;] mpi_powm+0x32/0x7e6
 RSP &lt;ffff880401297ad8&gt;
CR2: 0000000000000000
---[ end trace d82015255d4a5d8d ]---

Basically, this is a backport of a libgcrypt patch:

	http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=patch;h=6e1adb05d290aeeb1c230c763970695f4a538526

Fixes: cdec9cb5167a ("crypto: GnuPG based MPI lib - source files (part 1)")
Signed-off-by: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
cc: Dmitry Kasatkin &lt;dmitry.kasatkin@gmail.com&gt;
cc: linux-ima-devel@lists.sourceforge.net
cc: stable@vger.kernel.org
Signed-off-by: James Morris &lt;james.l.morris@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This fixes CVE-2016-8650.

If mpi_powm() is given a zero exponent, it wants to immediately return
either 1 or 0, depending on the modulus.  However, if the result was
initalised with zero limb space, no limbs space is allocated and a
NULL-pointer exception ensues.

Fix this by allocating a minimal amount of limb space for the result when
the 0-exponent case when the result is 1 and not touching the limb space
when the result is 0.

This affects the use of RSA keys and X.509 certificates that carry them.

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [&lt;ffffffff8138ce5d&gt;] mpi_powm+0x32/0x7e6
PGD 0
Oops: 0002 [#1] SMP
Modules linked in:
CPU: 3 PID: 3014 Comm: keyctl Not tainted 4.9.0-rc6-fscache+ #278
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
task: ffff8804011944c0 task.stack: ffff880401294000
RIP: 0010:[&lt;ffffffff8138ce5d&gt;]  [&lt;ffffffff8138ce5d&gt;] mpi_powm+0x32/0x7e6
RSP: 0018:ffff880401297ad8  EFLAGS: 00010212
RAX: 0000000000000000 RBX: ffff88040868bec0 RCX: ffff88040868bba0
RDX: ffff88040868b260 RSI: ffff88040868bec0 RDI: ffff88040868bee0
RBP: ffff880401297ba8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000047 R11: ffffffff8183b210 R12: 0000000000000000
R13: ffff8804087c7600 R14: 000000000000001f R15: ffff880401297c50
FS:  00007f7a7918c700(0000) GS:ffff88041fb80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000401250000 CR4: 00000000001406e0
Stack:
 ffff88040868bec0 0000000000000020 ffff880401297b00 ffffffff81376cd4
 0000000000000100 ffff880401297b10 ffffffff81376d12 ffff880401297b30
 ffffffff81376f37 0000000000000100 0000000000000000 ffff880401297ba8
Call Trace:
 [&lt;ffffffff81376cd4&gt;] ? __sg_page_iter_next+0x43/0x66
 [&lt;ffffffff81376d12&gt;] ? sg_miter_get_next_page+0x1b/0x5d
 [&lt;ffffffff81376f37&gt;] ? sg_miter_next+0x17/0xbd
 [&lt;ffffffff8138ba3a&gt;] ? mpi_read_raw_from_sgl+0xf2/0x146
 [&lt;ffffffff8132a95c&gt;] rsa_verify+0x9d/0xee
 [&lt;ffffffff8132acca&gt;] ? pkcs1pad_sg_set_buf+0x2e/0xbb
 [&lt;ffffffff8132af40&gt;] pkcs1pad_verify+0xc0/0xe1
 [&lt;ffffffff8133cb5e&gt;] public_key_verify_signature+0x1b0/0x228
 [&lt;ffffffff8133d974&gt;] x509_check_for_self_signed+0xa1/0xc4
 [&lt;ffffffff8133cdde&gt;] x509_cert_parse+0x167/0x1a1
 [&lt;ffffffff8133d609&gt;] x509_key_preparse+0x21/0x1a1
 [&lt;ffffffff8133c3d7&gt;] asymmetric_key_preparse+0x34/0x61
 [&lt;ffffffff812fc9f3&gt;] key_create_or_update+0x145/0x399
 [&lt;ffffffff812fe227&gt;] SyS_add_key+0x154/0x19e
 [&lt;ffffffff81001c2b&gt;] do_syscall_64+0x80/0x191
 [&lt;ffffffff816825e4&gt;] entry_SYSCALL64_slow_path+0x25/0x25
Code: 56 41 55 41 54 53 48 81 ec a8 00 00 00 44 8b 71 04 8b 42 04 4c 8b 67 18 45 85 f6 89 45 80 0f 84 b4 06 00 00 85 c0 75 2f 41 ff ce &lt;49&gt; c7 04 24 01 00 00 00 b0 01 75 0b 48 8b 41 18 48 83 38 01 0f
RIP  [&lt;ffffffff8138ce5d&gt;] mpi_powm+0x32/0x7e6
 RSP &lt;ffff880401297ad8&gt;
CR2: 0000000000000000
---[ end trace d82015255d4a5d8d ]---

Basically, this is a backport of a libgcrypt patch:

	http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=patch;h=6e1adb05d290aeeb1c230c763970695f4a538526

Fixes: cdec9cb5167a ("crypto: GnuPG based MPI lib - source files (part 1)")
Signed-off-by: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
cc: Dmitry Kasatkin &lt;dmitry.kasatkin@gmail.com&gt;
cc: linux-ima-devel@lists.sourceforge.net
cc: stable@vger.kernel.org
Signed-off-by: James Morris &lt;james.l.morris@oracle.com&gt;
</pre>
</div>
</content>
</entry>
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