<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/fs/crypto, branch v5.1</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt</title>
<updated>2019-03-09T18:54:24+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-09T18:54:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d1cae94871330cb9f5fdcea34529abf7917e682e'/>
<id>d1cae94871330cb9f5fdcea34529abf7917e682e</id>
<content type='text'>
Pull fscrypt updates from Eric Biggers:
 "First: Ted, Jaegeuk, and I have decided to add me as a co-maintainer
  for fscrypt, and we're now using a shared git tree. So we've updated
  MAINTAINERS accordingly, and I'm doing the pull request this time.

  The actual changes for v5.1 are:

   - Remove the fs-specific kconfig options like CONFIG_EXT4_ENCRYPTION
     and make fscrypt support for all fscrypt-capable filesystems be
     controlled by CONFIG_FS_ENCRYPTION, similar to how CONFIG_QUOTA
     works.

   - Improve error code for rename() and link() into encrypted
     directories.

   - Various cleanups"

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
  MAINTAINERS: add Eric Biggers as an fscrypt maintainer
  fscrypt: return -EXDEV for incompatible rename or link into encrypted dir
  fscrypt: remove filesystem specific build config option
  f2fs: use IS_ENCRYPTED() to check encryption status
  ext4: use IS_ENCRYPTED() to check encryption status
  fscrypt: remove CRYPTO_CTR dependency
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull fscrypt updates from Eric Biggers:
 "First: Ted, Jaegeuk, and I have decided to add me as a co-maintainer
  for fscrypt, and we're now using a shared git tree. So we've updated
  MAINTAINERS accordingly, and I'm doing the pull request this time.

  The actual changes for v5.1 are:

   - Remove the fs-specific kconfig options like CONFIG_EXT4_ENCRYPTION
     and make fscrypt support for all fscrypt-capable filesystems be
     controlled by CONFIG_FS_ENCRYPTION, similar to how CONFIG_QUOTA
     works.

   - Improve error code for rename() and link() into encrypted
     directories.

   - Various cleanups"

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
  MAINTAINERS: add Eric Biggers as an fscrypt maintainer
  fscrypt: return -EXDEV for incompatible rename or link into encrypted dir
  fscrypt: remove filesystem specific build config option
  f2fs: use IS_ENCRYPTED() to check encryption status
  ext4: use IS_ENCRYPTED() to check encryption status
  fscrypt: remove CRYPTO_CTR dependency
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block</title>
<updated>2019-03-08T22:12:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-08T22:12:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=80201fe175cbf7f3e372f53eba0a881a702ad926'/>
<id>80201fe175cbf7f3e372f53eba0a881a702ad926</id>
<content type='text'>
Pull block layer updates from Jens Axboe:
 "Not a huge amount of changes in this round, the biggest one is that we
  finally have Mings multi-page bvec support merged. Apart from that,
  this pull request contains:

   - Small series that avoids quiescing the queue for sysfs changes that
     match what we currently have (Aleksei)

   - Series of bcache fixes (via Coly)

   - Series of lightnvm fixes (via Mathias)

   - NVMe pull request from Christoph. Nothing major, just SPDX/license
     cleanups, RR mp policy (Hannes), and little fixes (Bart,
     Chaitanya).

   - BFQ series (Paolo)

   - Save blk-mq cpu -&gt; hw queue mapping, removing a pointer indirection
     for the fast path (Jianchao)

   - fops-&gt;iopoll() added for async IO polling, this is a feature that
     the upcoming io_uring interface will use (Christoph, me)

   - Partition scan loop fixes (Dongli)

   - mtip32xx conversion from managed resource API (Christoph)

   - cdrom registration race fix (Guenter)

   - MD pull from Song, two minor fixes.

   - Various documentation fixes (Marcos)

   - Multi-page bvec feature. This brings a lot of nice improvements
     with it, like more efficient splitting, larger IOs can be supported
     without growing the bvec table size, and so on. (Ming)

   - Various little fixes to core and drivers"

* tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block: (117 commits)
  block: fix updating bio's front segment size
  block: Replace function name in string with __func__
  nbd: propagate genlmsg_reply return code
  floppy: remove set but not used variable 'q'
  null_blk: fix checking for REQ_FUA
  block: fix NULL pointer dereference in register_disk
  fs: fix guard_bio_eod to check for real EOD errors
  blk-mq: use HCTX_TYPE_DEFAULT but not 0 to index blk_mq_tag_set-&gt;map
  block: optimize bvec iteration in bvec_iter_advance
  block: introduce mp_bvec_for_each_page() for iterating over page
  block: optimize blk_bio_segment_split for single-page bvec
  block: optimize __blk_segment_map_sg() for single-page bvec
  block: introduce bvec_nth_page()
  iomap: wire up the iopoll method
  block: add bio_set_polled() helper
  block: wire up block device iopoll method
  fs: add an iopoll method to struct file_operations
  loop: set GENHD_FL_NO_PART_SCAN after blkdev_reread_part()
  loop: do not print warn message if partition scan is successful
  block: bounce: make sure that bvec table is updated
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull block layer updates from Jens Axboe:
 "Not a huge amount of changes in this round, the biggest one is that we
  finally have Mings multi-page bvec support merged. Apart from that,
  this pull request contains:

   - Small series that avoids quiescing the queue for sysfs changes that
     match what we currently have (Aleksei)

   - Series of bcache fixes (via Coly)

   - Series of lightnvm fixes (via Mathias)

   - NVMe pull request from Christoph. Nothing major, just SPDX/license
     cleanups, RR mp policy (Hannes), and little fixes (Bart,
     Chaitanya).

   - BFQ series (Paolo)

   - Save blk-mq cpu -&gt; hw queue mapping, removing a pointer indirection
     for the fast path (Jianchao)

   - fops-&gt;iopoll() added for async IO polling, this is a feature that
     the upcoming io_uring interface will use (Christoph, me)

   - Partition scan loop fixes (Dongli)

   - mtip32xx conversion from managed resource API (Christoph)

   - cdrom registration race fix (Guenter)

   - MD pull from Song, two minor fixes.

   - Various documentation fixes (Marcos)

   - Multi-page bvec feature. This brings a lot of nice improvements
     with it, like more efficient splitting, larger IOs can be supported
     without growing the bvec table size, and so on. (Ming)

   - Various little fixes to core and drivers"

* tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block: (117 commits)
  block: fix updating bio's front segment size
  block: Replace function name in string with __func__
  nbd: propagate genlmsg_reply return code
  floppy: remove set but not used variable 'q'
  null_blk: fix checking for REQ_FUA
  block: fix NULL pointer dereference in register_disk
  fs: fix guard_bio_eod to check for real EOD errors
  blk-mq: use HCTX_TYPE_DEFAULT but not 0 to index blk_mq_tag_set-&gt;map
  block: optimize bvec iteration in bvec_iter_advance
  block: introduce mp_bvec_for_each_page() for iterating over page
  block: optimize blk_bio_segment_split for single-page bvec
  block: optimize __blk_segment_map_sg() for single-page bvec
  block: introduce bvec_nth_page()
  iomap: wire up the iopoll method
  block: add bio_set_polled() helper
  block: wire up block device iopoll method
  fs: add an iopoll method to struct file_operations
  loop: set GENHD_FL_NO_PART_SCAN after blkdev_reread_part()
  loop: do not print warn message if partition scan is successful
  block: bounce: make sure that bvec table is updated
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>block: allow bio_for_each_segment_all() to iterate over multi-page bvec</title>
<updated>2019-02-15T15:40:11+00:00</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2019-02-15T11:13:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6dc4f100c175dd0511ae8674786e7c9006cdfbfa'/>
<id>6dc4f100c175dd0511ae8674786e7c9006cdfbfa</id>
<content type='text'>
This patch introduces one extra iterator variable to bio_for_each_segment_all(),
then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.

Given it is just one mechannical &amp; simple change on all bio_for_each_segment_all()
users, this patch does tree-wide change in one single patch, so that we can
avoid to use a temporary helper for this conversion.

Reviewed-by: Omar Sandoval &lt;osandov@fb.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch introduces one extra iterator variable to bio_for_each_segment_all(),
then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.

Given it is just one mechannical &amp; simple change on all bio_for_each_segment_all()
users, this patch does tree-wide change in one single patch, so that we can
avoid to use a temporary helper for this conversion.

Reviewed-by: Omar Sandoval &lt;osandov@fb.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: clarify name of WEAK_KEY request flag</title>
<updated>2019-01-25T10:41:52+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2019-01-19T06:48:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=231baecdef7a906579925ccf1bd45aa734f32320'/>
<id>231baecdef7a906579925ccf1bd45aa734f32320</id>
<content type='text'>
CRYPTO_TFM_REQ_WEAK_KEY confuses newcomers to the crypto API because it
sounds like it is requesting a weak key.  Actually, it is requesting
that weak keys be forbidden (for algorithms that have the notion of
"weak keys"; currently only DES and XTS do).

Also it is only one letter away from CRYPTO_TFM_RES_WEAK_KEY, with which
it can be easily confused.  (This in fact happened in the UX500 driver,
though just in some debugging messages.)

Therefore, make the intent clear by renaming it to
CRYPTO_TFM_REQ_FORBID_WEAK_KEYS.

Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
CRYPTO_TFM_REQ_WEAK_KEY confuses newcomers to the crypto API because it
sounds like it is requesting a weak key.  Actually, it is requesting
that weak keys be forbidden (for algorithms that have the notion of
"weak keys"; currently only DES and XTS do).

Also it is only one letter away from CRYPTO_TFM_RES_WEAK_KEY, with which
it can be easily confused.  (This in fact happened in the UX500 driver,
though just in some debugging messages.)

Therefore, make the intent clear by renaming it to
CRYPTO_TFM_REQ_FORBID_WEAK_KEYS.

Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fscrypt: return -EXDEV for incompatible rename or link into encrypted dir</title>
<updated>2019-01-24T04:56:43+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2019-01-23T00:20:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f5e55e777cc93eae1416f0fa4908e8846b6d7825'/>
<id>f5e55e777cc93eae1416f0fa4908e8846b6d7825</id>
<content type='text'>
Currently, trying to rename or link a regular file, directory, or
symlink into an encrypted directory fails with EPERM when the source
file is unencrypted or is encrypted with a different encryption policy,
and is on the same mountpoint.  It is correct for the operation to fail,
but the choice of EPERM breaks tools like 'mv' that know to copy rather
than rename if they see EXDEV, but don't know what to do with EPERM.

Our original motivation for EPERM was to encourage users to securely
handle their data.  Encrypting files by "moving" them into an encrypted
directory can be insecure because the unencrypted data may remain in
free space on disk, where it can later be recovered by an attacker.
It's much better to encrypt the data from the start, or at least try to
securely delete the source data e.g. using the 'shred' program.

However, the current behavior hasn't been effective at achieving its
goal because users tend to be confused, hack around it, and complain;
see e.g. https://github.com/google/fscrypt/issues/76.  And in some cases
it's actually inconsistent or unnecessary.  For example, 'mv'-ing files
between differently encrypted directories doesn't work even in cases
where it can be secure, such as when in userspace the same passphrase
protects both directories.  Yet, you *can* already 'mv' unencrypted
files into an encrypted directory if the source files are on a different
mountpoint, even though doing so is often insecure.

There are probably better ways to teach users to securely handle their
files.  For example, the 'fscrypt' userspace tool could provide a
command that migrates unencrypted files into an encrypted directory,
acting like 'shred' on the source files and providing appropriate
warnings depending on the type of the source filesystem and disk.

Receiving errors on unimportant files might also force some users to
disable encryption, thus making the behavior counterproductive.  It's
desirable to make encryption as unobtrusive as possible.

Therefore, change the error code from EPERM to EXDEV so that tools
looking for EXDEV will fall back to a copy.

This, of course, doesn't prevent users from still doing the right things
to securely manage their files.  Note that this also matches the
behavior when a file is renamed between two project quota hierarchies;
so there's precedent for using EXDEV for things other than mountpoints.

xfstests generic/398 will require an update with this change.

[Rewritten from an earlier patch series by Michael Halcrow.]

Cc: Michael Halcrow &lt;mhalcrow@google.com&gt;
Cc: Joe Richey &lt;joerichey@google.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, trying to rename or link a regular file, directory, or
symlink into an encrypted directory fails with EPERM when the source
file is unencrypted or is encrypted with a different encryption policy,
and is on the same mountpoint.  It is correct for the operation to fail,
but the choice of EPERM breaks tools like 'mv' that know to copy rather
than rename if they see EXDEV, but don't know what to do with EPERM.

Our original motivation for EPERM was to encourage users to securely
handle their data.  Encrypting files by "moving" them into an encrypted
directory can be insecure because the unencrypted data may remain in
free space on disk, where it can later be recovered by an attacker.
It's much better to encrypt the data from the start, or at least try to
securely delete the source data e.g. using the 'shred' program.

However, the current behavior hasn't been effective at achieving its
goal because users tend to be confused, hack around it, and complain;
see e.g. https://github.com/google/fscrypt/issues/76.  And in some cases
it's actually inconsistent or unnecessary.  For example, 'mv'-ing files
between differently encrypted directories doesn't work even in cases
where it can be secure, such as when in userspace the same passphrase
protects both directories.  Yet, you *can* already 'mv' unencrypted
files into an encrypted directory if the source files are on a different
mountpoint, even though doing so is often insecure.

There are probably better ways to teach users to securely handle their
files.  For example, the 'fscrypt' userspace tool could provide a
command that migrates unencrypted files into an encrypted directory,
acting like 'shred' on the source files and providing appropriate
warnings depending on the type of the source filesystem and disk.

Receiving errors on unimportant files might also force some users to
disable encryption, thus making the behavior counterproductive.  It's
desirable to make encryption as unobtrusive as possible.

Therefore, change the error code from EPERM to EXDEV so that tools
looking for EXDEV will fall back to a copy.

This, of course, doesn't prevent users from still doing the right things
to securely manage their files.  Note that this also matches the
behavior when a file is renamed between two project quota hierarchies;
so there's precedent for using EXDEV for things other than mountpoints.

xfstests generic/398 will require an update with this change.

[Rewritten from an earlier patch series by Michael Halcrow.]

Cc: Michael Halcrow &lt;mhalcrow@google.com&gt;
Cc: Joe Richey &lt;joerichey@google.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fscrypt: remove filesystem specific build config option</title>
<updated>2019-01-24T04:56:43+00:00</updated>
<author>
<name>Chandan Rajendra</name>
<email>chandan@linux.vnet.ibm.com</email>
</author>
<published>2018-12-12T09:50:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=643fa9612bf1a29153eee46fd398117632f93cbe'/>
<id>643fa9612bf1a29153eee46fd398117632f93cbe</id>
<content type='text'>
In order to have a common code base for fscrypt "post read" processing
for all filesystems which support encryption, this commit removes
filesystem specific build config option (e.g. CONFIG_EXT4_FS_ENCRYPTION)
and replaces it with a build option (i.e. CONFIG_FS_ENCRYPTION) whose
value affects all the filesystems making use of fscrypt.

Reviewed-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Chandan Rajendra &lt;chandan@linux.vnet.ibm.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In order to have a common code base for fscrypt "post read" processing
for all filesystems which support encryption, this commit removes
filesystem specific build config option (e.g. CONFIG_EXT4_FS_ENCRYPTION)
and replaces it with a build option (i.e. CONFIG_FS_ENCRYPTION) whose
value affects all the filesystems making use of fscrypt.

Reviewed-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Chandan Rajendra &lt;chandan@linux.vnet.ibm.com&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fscrypt: remove CRYPTO_CTR dependency</title>
<updated>2019-01-24T04:56:43+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2018-09-05T19:24:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1058ef0dcb7116fc49270131fda3037fddcc6595'/>
<id>1058ef0dcb7116fc49270131fda3037fddcc6595</id>
<content type='text'>
fscrypt doesn't use the CTR mode of operation for anything, so there's
no need to select CRYPTO_CTR.  It was added by commit 71dea01ea2ed
("ext4 crypto: require CONFIG_CRYPTO_CTR if ext4 encryption is
enabled").  But, I've been unable to identify the arm64 crypto bug it
was supposedly working around.

I suspect the issue was seen only on some old Android device kernel
(circa 3.10?).  So if the fix wasn't mistaken, the real bug is probably
already fixed.  Or maybe it was actually a bug in a non-upstream crypto
driver.

So, remove the dependency.  If it turns out there's actually still a
bug, we'll fix it properly.

Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
fscrypt doesn't use the CTR mode of operation for anything, so there's
no need to select CRYPTO_CTR.  It was added by commit 71dea01ea2ed
("ext4 crypto: require CONFIG_CRYPTO_CTR if ext4 encryption is
enabled").  But, I've been unable to identify the arm64 crypto bug it
was supposedly working around.

I suspect the issue was seen only on some old Android device kernel
(circa 3.10?).  So if the fix wasn't mistaken, the real bug is probably
already fixed.  Or maybe it was actually a bug in a non-upstream crypto
driver.

So, remove the dependency.  If it turns out there's actually still a
bug, we'll fix it properly.

Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fscrypt: add Adiantum support</title>
<updated>2019-01-06T13:36:21+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2019-01-06T13:36:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8094c3ceb21ad93896fd4d238e8ba41911932eaf'/>
<id>8094c3ceb21ad93896fd4d238e8ba41911932eaf</id>
<content type='text'>
Add support for the Adiantum encryption mode to fscrypt.  Adiantum is a
tweakable, length-preserving encryption mode with security provably
reducible to that of XChaCha12 and AES-256, subject to a security bound.
It's also a true wide-block mode, unlike XTS.  See the paper
"Adiantum: length-preserving encryption for entry-level processors"
(https://eprint.iacr.org/2018/720.pdf) for more details.  Also see
commit 059c2a4d8e16 ("crypto: adiantum - add Adiantum support").

On sufficiently long messages, Adiantum's bottlenecks are XChaCha12 and
the NH hash function.  These algorithms are fast even on processors
without dedicated crypto instructions.  Adiantum makes it feasible to
enable storage encryption on low-end mobile devices that lack AES
instructions; currently such devices are unencrypted.  On ARM Cortex-A7,
on 4096-byte messages Adiantum encryption is about 4 times faster than
AES-256-XTS encryption; decryption is about 5 times faster.

In fscrypt, Adiantum is suitable for encrypting both file contents and
names.  With filenames, it fixes a known weakness: when two filenames in
a directory share a common prefix of &gt;= 16 bytes, with CTS-CBC their
encrypted filenames share a common prefix too, leaking information.
Adiantum does not have this problem.

Since Adiantum also accepts long tweaks (IVs), it's also safe to use the
master key directly for Adiantum encryption rather than deriving
per-file keys, provided that the per-file nonce is included in the IVs
and the master key isn't used for any other encryption mode.  This
configuration saves memory and improves performance.  A new fscrypt
policy flag is added to allow users to opt-in to this configuration.

Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add support for the Adiantum encryption mode to fscrypt.  Adiantum is a
tweakable, length-preserving encryption mode with security provably
reducible to that of XChaCha12 and AES-256, subject to a security bound.
It's also a true wide-block mode, unlike XTS.  See the paper
"Adiantum: length-preserving encryption for entry-level processors"
(https://eprint.iacr.org/2018/720.pdf) for more details.  Also see
commit 059c2a4d8e16 ("crypto: adiantum - add Adiantum support").

On sufficiently long messages, Adiantum's bottlenecks are XChaCha12 and
the NH hash function.  These algorithms are fast even on processors
without dedicated crypto instructions.  Adiantum makes it feasible to
enable storage encryption on low-end mobile devices that lack AES
instructions; currently such devices are unencrypted.  On ARM Cortex-A7,
on 4096-byte messages Adiantum encryption is about 4 times faster than
AES-256-XTS encryption; decryption is about 5 times faster.

In fscrypt, Adiantum is suitable for encrypting both file contents and
names.  With filenames, it fixes a known weakness: when two filenames in
a directory share a common prefix of &gt;= 16 bytes, with CTS-CBC their
encrypted filenames share a common prefix too, leaking information.
Adiantum does not have this problem.

Since Adiantum also accepts long tweaks (IVs), it's also safe to use the
master key directly for Adiantum encryption rather than deriving
per-file keys, provided that the per-file nonce is included in the IVs
and the master key isn't used for any other encryption mode.  This
configuration saves memory and improves performance.  A new fscrypt
policy flag is added to allow users to opt-in to this configuration.

Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>crypto: speck - remove Speck</title>
<updated>2018-09-04T03:35:03+00:00</updated>
<author>
<name>Jason A. Donenfeld</name>
<email>Jason@zx2c4.com</email>
</author>
<published>2018-08-07T06:22:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=578bdaabd015b9b164842c3e8ace9802f38e7ecc'/>
<id>578bdaabd015b9b164842c3e8ace9802f38e7ecc</id>
<content type='text'>
These are unused, undesired, and have never actually been used by
anybody. The original authors of this code have changed their mind about
its inclusion. While originally proposed for disk encryption on low-end
devices, the idea was discarded [1] in favor of something else before
that could really get going. Therefore, this patch removes Speck.

[1] https://marc.info/?l=linux-crypto-vger&amp;m=153359499015659

Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Acked-by: Eric Biggers &lt;ebiggers@google.com&gt;
Cc: stable@vger.kernel.org
Acked-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
These are unused, undesired, and have never actually been used by
anybody. The original authors of this code have changed their mind about
its inclusion. While originally proposed for disk encryption on low-end
devices, the idea was discarded [1] in favor of something else before
that could really get going. Therefore, this patch removes Speck.

[1] https://marc.info/?l=linux-crypto-vger&amp;m=153359499015659

Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Acked-by: Eric Biggers &lt;ebiggers@google.com&gt;
Cc: stable@vger.kernel.org
Acked-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'f2fs-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs</title>
<updated>2018-06-11T17:16:13+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-06-11T17:16:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d54d35c501bcbd57b9722a6b371c0608b5d34199'/>
<id>d54d35c501bcbd57b9722a6b371c0608b5d34199</id>
<content type='text'>
Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've mainly focused on discard, aka unmap, control
  along with fstrim for Android-specific usage model. In addition, we've
  fixed writepage flow which returned EAGAIN previously resulting in EIO
  of fsync(2) due to mapping's error state. In order to avoid old MM bug
  [1], we decided not to use __GFP_ZERO for the mapping for node and
  meta page caches. As always, we've cleaned up many places for future
  fsverity and symbol conflicts.

  Enhancements:
   - do discard/fstrim in lower priority considering fs utilization
   - split large discard commands into smaller ones for better responsiveness
   - add more sanity checks to address syzbot reports
   - add a mount option, fsync_mode=nobarrier, which can reduce # of cache flushes
   - clean up symbol namespace with modified function names
   - be strict on block allocation and IO control in corner cases

  Bug fixes:
   - don't use __GFP_ZERO for mappings
   - fix error reports in writepage to avoid fsync() failure
   - avoid selinux denial on CAP_RESOURCE on resgid/resuid
   - fix some subtle race conditions in GC/atomic writes/shutdown
   - fix overflow bugs in sanity_check_raw_super
   - fix missing bits on get_flags

  Clean-ups:
   - prepare the generic flow for future fsverity integration
   - fix some broken coding standard"

[1] https://lkml.org/lkml/2018/4/8/661

* tag 'f2fs-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (79 commits)
  f2fs: fix to clear FI_VOLATILE_FILE correctly
  f2fs: let sync node IO interrupt async one
  f2fs: don't change wbc-&gt;sync_mode
  f2fs: fix to update mtime correctly
  fs: f2fs: insert space around that ':' and ', '
  fs: f2fs: add missing blank lines after declarations
  fs: f2fs: changed variable type of offset "unsigned" to "loff_t"
  f2fs: clean up symbol namespace
  f2fs: make set_de_type() static
  f2fs: make __f2fs_write_data_pages() static
  f2fs: fix to avoid accessing cross the boundary
  f2fs: fix to let caller retry allocating block address
  disable loading f2fs module on PAGE_SIZE &gt; 4KB
  f2fs: fix error path of move_data_page
  f2fs: don't drop dentry pages after fs shutdown
  f2fs: fix to avoid race during access gc_thread pointer
  f2fs: clean up with clear_radix_tree_dirty_tag
  f2fs: fix to don't trigger writeback during recovery
  f2fs: clear discard_wake earlier
  f2fs: let discard thread wait a little longer if dev is busy
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've mainly focused on discard, aka unmap, control
  along with fstrim for Android-specific usage model. In addition, we've
  fixed writepage flow which returned EAGAIN previously resulting in EIO
  of fsync(2) due to mapping's error state. In order to avoid old MM bug
  [1], we decided not to use __GFP_ZERO for the mapping for node and
  meta page caches. As always, we've cleaned up many places for future
  fsverity and symbol conflicts.

  Enhancements:
   - do discard/fstrim in lower priority considering fs utilization
   - split large discard commands into smaller ones for better responsiveness
   - add more sanity checks to address syzbot reports
   - add a mount option, fsync_mode=nobarrier, which can reduce # of cache flushes
   - clean up symbol namespace with modified function names
   - be strict on block allocation and IO control in corner cases

  Bug fixes:
   - don't use __GFP_ZERO for mappings
   - fix error reports in writepage to avoid fsync() failure
   - avoid selinux denial on CAP_RESOURCE on resgid/resuid
   - fix some subtle race conditions in GC/atomic writes/shutdown
   - fix overflow bugs in sanity_check_raw_super
   - fix missing bits on get_flags

  Clean-ups:
   - prepare the generic flow for future fsverity integration
   - fix some broken coding standard"

[1] https://lkml.org/lkml/2018/4/8/661

* tag 'f2fs-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (79 commits)
  f2fs: fix to clear FI_VOLATILE_FILE correctly
  f2fs: let sync node IO interrupt async one
  f2fs: don't change wbc-&gt;sync_mode
  f2fs: fix to update mtime correctly
  fs: f2fs: insert space around that ':' and ', '
  fs: f2fs: add missing blank lines after declarations
  fs: f2fs: changed variable type of offset "unsigned" to "loff_t"
  f2fs: clean up symbol namespace
  f2fs: make set_de_type() static
  f2fs: make __f2fs_write_data_pages() static
  f2fs: fix to avoid accessing cross the boundary
  f2fs: fix to let caller retry allocating block address
  disable loading f2fs module on PAGE_SIZE &gt; 4KB
  f2fs: fix error path of move_data_page
  f2fs: don't drop dentry pages after fs shutdown
  f2fs: fix to avoid race during access gc_thread pointer
  f2fs: clean up with clear_radix_tree_dirty_tag
  f2fs: fix to don't trigger writeback during recovery
  f2fs: clear discard_wake earlier
  f2fs: let discard thread wait a little longer if dev is busy
  ...
</pre>
</div>
</content>
</entry>
</feed>
