linux.git/security/keys, branch v4.13

Merge tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2017-07-19T15:55:18+00:00

Pull structure randomization updates from Kees Cook:
 "Now that IPC and other changes have landed, enable manual markings for
  randstruct plugin, including the task_struct.

  This is the rest of what was staged in -next for the gcc-plugins, and
  comes in three patches, largest first:

   - mark "easy" structs with __randomize_layout

   - mark task_struct with an optional anonymous struct to isolate the
     __randomize_layout section

   - mark structs to opt _out_ of automated marking (which will come
     later)

  And, FWIW, this continues to pass allmodconfig (normal and patched to
  enable gcc-plugins) builds of x86_64, i386, arm64, arm, powerpc, and
  s390 for me"

* tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  randstruct: opt-out externally exposed function pointer structs
  task_struct: Allow randomized layout
  randstruct: Mark various structs for randomization

KEYS: DH: validate __spare field

2017-07-14T01:01:38+00:00

Syscalls must validate that their reserved arguments are zero and return
EINVAL otherwise.  Otherwise, it will be impossible to actually use them
for anything in the future because existing programs may be passing
garbage in.  This is standard practice when adding new APIs.

Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers 
Signed-off-by: David Howells 
Signed-off-by: James Morris

Merge tag 'docs-4.13' of git://git.lwn.net/linux

2017-07-04T04:13:25+00:00

Pull documentation updates from Jonathan Corbet:
 "There has been a fair amount of activity in the docs tree this time
  around. Highlights include:

   - Conversion of a bunch of security documentation into RST

   - The conversion of the remaining DocBook templates by The Amazing
     Mauro Machine. We can now drop the entire DocBook build chain.

   - The usual collection of fixes and minor updates"

* tag 'docs-4.13' of git://git.lwn.net/linux: (90 commits)
  scripts/kernel-doc: handle DECLARE_HASHTABLE
  Documentation: atomic_ops.txt is core-api/atomic_ops.rst
  Docs: clean up some DocBook loose ends
  Make the main documentation title less Geocities
  Docs: Use kernel-figure in vidioc-g-selection.rst
  Docs: fix table problems in ras.rst
  Docs: Fix breakage with Sphinx 1.5 and upper
  Docs: Include the Latex "ifthen" package
  doc/kokr/howto: Only send regression fixes after -rc1
  docs-rst: fix broken links to dynamic-debug-howto in kernel-parameters
  doc: Document suitability of IBM Verse for kernel development
  Doc: fix a markup error in coding-style.rst
  docs: driver-api: i2c: remove some outdated information
  Documentation: DMA API: fix a typo in a function name
  Docs: Insert missing space to separate link from text
  doc/ko_KR/memory-barriers: Update control-dependencies example
  Documentation, kbuild: fix typo "minimun" -> "minimum"
  docs: Fix some formatting issues in request-key.rst
  doc: ReSTify keys-trusted-encrypted.txt
  doc: ReSTify keys-request-key.txt
  ...

randstruct: Mark various structs for randomization

2017-06-30T19:00:51+00:00

This marks many critical kernel structures for randomization. These are
structures that have been targeted in the past in security exploits, or
contain functions pointers, pointers to function pointer tables, lists,
workqueues, ref-counters, credentials, permissions, or are otherwise
sensitive. This initial list was extracted from Brad Spengler/PaX Team's
code in the last public patch of grsecurity/PaX based on my understanding
of the code. Changes or omissions from the original code are mine and
don't reflect the original grsecurity/PaX code.

Left out of this list is task_struct, which requires special handling
and will be covered in a subsequent patch.

Signed-off-by: Kees Cook

sched/wait: Split out the wait_bit*() APIs from into

2017-06-20T10:19:09+00:00

The wait_bit*() types and APIs are mixed into wait.h, but they
are a pretty orthogonal extension of wait-queues.

Furthermore, only about 50 kernel files use these APIs, while
over 1000 use the regular wait-queue functionality.

So clean up the main wait.h by moving the wait-bit functionality
out of it, into a separate .h and .c file:

  include/linux/wait_bit.h  for types and APIs
  kernel/sched/wait_bit.c   for the implementation

Update all header dependencies.

This reduces the size of wait.h rather significantly, by about 30%.

Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

KEYS: fix refcount_inc() on zero

2017-06-09T03:29:50+00:00

If a key's refcount is dropped to zero between key_lookup() peeking at
the refcount and subsequently attempting to increment it, refcount_inc()
will see a zero refcount.  Here, refcount_inc() will WARN_ONCE(), and
will *not* increment the refcount, which will remain zero.

Once key_lookup() drops key_serial_lock, it is possible for the key to
be freed behind our back.

This patch uses refcount_inc_not_zero() to perform the peek and increment
atomically.

Fixes: fff292914d3a2f1e ("security, keys: convert key.usage from atomic_t to refcount_t")
Signed-off-by: Mark Rutland 
Signed-off-by: David Howells 
Cc: David Windsor 
Cc: Elena Reshetova 
Cc: Hans Liljestrand 
Cc: James Morris 
Cc: Kees Cook 
Cc: Peter Zijlstra 
Signed-off-by: James Morris

KEYS: Convert KEYCTL_DH_COMPUTE to use the crypto KPP API

2017-06-09T03:29:50+00:00

The initial Diffie-Hellman computation made direct use of the MPI
library because the crypto module did not support DH at the time. Now
that KPP is implemented, KEYCTL_DH_COMPUTE should use it to get rid of
duplicate code and leverage possible hardware acceleration.

This fixes an issue whereby the input to the KDF computation would
include additional uninitialized memory when the result of the
Diffie-Hellman computation was shorter than the input prime number.

Signed-off-by: Mat Martineau 
Signed-off-by: David Howells 
Signed-off-by: James Morris

KEYS: DH: ensure the KDF counter is properly aligned

2017-06-09T03:29:49+00:00

Accessing a 'u8[4]' through a '__be32 *' violates alignment rules.  Just
make the counter a __be32 instead.

Signed-off-by: Eric Biggers 
Signed-off-by: David Howells 
Acked-by: Stephan Mueller 
Signed-off-by: James Morris

KEYS: DH: don't feed uninitialized "otherinfo" into KDF

2017-06-09T03:29:49+00:00

If userspace called KEYCTL_DH_COMPUTE with kdf_params containing NULL
otherinfo but nonzero otherinfolen, the kernel would allocate a buffer
for the otherinfo, then feed it into the KDF without initializing it.
Fix this by always doing the copy from userspace (which will fail with
EFAULT in this scenario).

Signed-off-by: Eric Biggers 
Signed-off-by: David Howells 
Acked-by: Stephan Mueller 
Signed-off-by: James Morris

KEYS: DH: forbid using digest_null as the KDF hash

2017-06-09T03:29:49+00:00

Requesting "digest_null" in the keyctl_kdf_params caused an infinite
loop in kdf_ctr() because the "null" hash has a digest size of 0.  Fix
it by rejecting hash algorithms with a digest size of 0.

Signed-off-by: Eric Biggers 
Signed-off-by: David Howells 
Acked-by: Stephan Mueller 
Signed-off-by: James Morris