linux-stable.git/security/keys/encrypted-keys, branch linux-4.15.y Linux kernel stable tree License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02T10:10:55+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2017-11-01T14:07:57+00:00 b24413180f5600bcb3bb70fbed5cf186b60864bd Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KEYS: Fix race between updating and finding a negative key 2017-10-18T08:12:40+00:00 David Howells dhowells@redhat.com 2017-10-04T15:43:25+00:00 363b02dab09b3226f3bd1420dad9c72b79a42a76 Consolidate KEY_FLAG_INSTANTIATED, KEY_FLAG_NEGATIVE and the rejection error into one field such that: (1) The instantiation state can be modified/read atomically. (2) The error can be accessed atomically with the state. (3) The error isn't stored unioned with the payload pointers. This deals with the problem that the state is spread over three different objects (two bits and a separate variable) and reading or updating them atomically isn't practical, given that not only can uninstantiated keys change into instantiated or rejected keys, but rejected keys can also turn into instantiated keys - and someone accessing the key might not be using any locking. The main side effect of this problem is that what was held in the payload may change, depending on the state. For instance, you might observe the key to be in the rejected state. You then read the cached error, but if the key semaphore wasn't locked, the key might've become instantiated between the two reads - and you might now have something in hand that isn't actually an error code. The state is now KEY_IS_UNINSTANTIATED, KEY_IS_POSITIVE or a negative error code if the key is negatively instantiated. The key_is_instantiated() function is replaced with key_is_positive() to avoid confusion as negative keys are also 'instantiated'. Additionally, barriering is included: (1) Order payload-set before state-set during instantiation. (2) Order state-read before payload-read when using the key. Further separate barriering is necessary if RCU is being used to access the payload content after reading the payload pointers. Fixes: 146aa8b1453b ("KEYS: Merge the type-specific data with the payload data") Cc: stable@vger.kernel.org # v4.4+ Reported-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Eric Biggers <ebiggers@google.com> 
Consolidate KEY_FLAG_INSTANTIATED, KEY_FLAG_NEGATIVE and the rejection
error into one field such that:

 (1) The instantiation state can be modified/read atomically.

 (2) The error can be accessed atomically with the state.

 (3) The error isn't stored unioned with the payload pointers.

This deals with the problem that the state is spread over three different
objects (two bits and a separate variable) and reading or updating them
atomically isn't practical, given that not only can uninstantiated keys
change into instantiated or rejected keys, but rejected keys can also turn
into instantiated keys - and someone accessing the key might not be using
any locking.

The main side effect of this problem is that what was held in the payload
may change, depending on the state.  For instance, you might observe the
key to be in the rejected state.  You then read the cached error, but if
the key semaphore wasn't locked, the key might've become instantiated
between the two reads - and you might now have something in hand that isn't
actually an error code.

The state is now KEY_IS_UNINSTANTIATED, KEY_IS_POSITIVE or a negative error
code if the key is negatively instantiated.  The key_is_instantiated()
function is replaced with key_is_positive() to avoid confusion as negative
keys are also 'instantiated'.

Additionally, barriering is included:

 (1) Order payload-set before state-set during instantiation.

 (2) Order state-read before payload-read when using the key.

Further separate barriering is necessary if RCU is being used to access the
payload content after reading the payload pointers.

Fixes: 146aa8b1453b ("KEYS: Merge the type-specific data with the payload data")
Cc: stable@vger.kernel.org # v4.4+
Reported-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
KEYS: encrypted: fix dereference of NULL user_key_payload 2017-10-12T14:55:09+00:00 Eric Biggers ebiggers@google.com 2017-10-09T19:37:49+00:00 13923d0865ca96312197962522e88bc0aedccd74 A key of type "encrypted" references a "master key" which is used to encrypt and decrypt the encrypted key's payload. However, when we accessed the master key's payload, we failed to handle the case where the master key has been revoked, which sets the payload pointer to NULL. Note that request_key() *does* skip revoked keys, but there is still a window where the key can be revoked before we acquire its semaphore. Fix it by checking for a NULL payload, treating it like a key which was already revoked at the time it was requested. This was an issue for master keys of type "user" only. Master keys can also be of type "trusted", but those cannot be revoked. Fixes: 7e70cb497850 ("keys: add new key-type encrypted") Reviewed-by: James Morris <james.l.morris@oracle.com> Cc: <stable@vger.kernel.org> [v2.6.38+] Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: David Safford <safford@us.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> 
A key of type "encrypted" references a "master key" which is used to
encrypt and decrypt the encrypted key's payload.  However, when we
accessed the master key's payload, we failed to handle the case where
the master key has been revoked, which sets the payload pointer to NULL.
Note that request_key() *does* skip revoked keys, but there is still a
window where the key can be revoked before we acquire its semaphore.

Fix it by checking for a NULL payload, treating it like a key which was
already revoked at the time it was requested.

This was an issue for master keys of type "user" only.  Master keys can
also be of type "trusted", but those cannot be revoked.

Fixes: 7e70cb497850 ("keys: add new key-type encrypted")
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: <stable@vger.kernel.org>    [v2.6.38+]
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: David Safford <safford@us.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Merge tag 'docs-4.13' of git://git.lwn.net/linux 2017-07-04T04:13:25+00:00 Linus Torvalds torvalds@linux-foundation.org 2017-07-04T04:13:25+00:00 650fc870a2ef35b83397eebd35b8c8df211bff78 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 ... 
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
  ...
KEYS: encrypted: sanitize all key material 2017-06-09T03:29:48+00:00 Eric Biggers ebiggers@google.com 2017-06-08T13:49:11+00:00 a9dd74b252e04b7e41ffe78d418b896b33b70a13 For keys of type "encrypted", consistently zero sensitive key material before freeing it. This was already being done for the decrypted payloads of encrypted keys, but not for the master key and the keys derived from the master key. Out of an abundance of caution and because it is trivial to do so, also zero buffers containing the key payload in encrypted form, although depending on how the encrypted-keys feature is used such information does not necessarily need to be kept secret. Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: David Safford <safford@us.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com> 
For keys of type "encrypted", consistently zero sensitive key material
before freeing it.  This was already being done for the decrypted
payloads of encrypted keys, but not for the master key and the keys
derived from the master key.

Out of an abundance of caution and because it is trivial to do so, also
zero buffers containing the key payload in encrypted form, although
depending on how the encrypted-keys feature is used such information
does not necessarily need to be kept secret.

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: David Safford <safford@us.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
KEYS: encrypted: use constant-time HMAC comparison 2017-06-09T03:29:47+00:00 Eric Biggers ebiggers@google.com 2017-06-08T13:48:32+00:00 0f534e4a13496b02ae284f50fcb0263f6ea37007 MACs should, in general, be compared using crypto_memneq() to prevent timing attacks. Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com> 
MACs should, in general, be compared using crypto_memneq() to prevent
timing attacks.

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
KEYS: encrypted: fix race causing incorrect HMAC calculations 2017-06-09T03:29:47+00:00 Eric Biggers ebiggers@google.com 2017-06-08T13:48:25+00:00 64d107d3acca1565c39c044c459fd18f70943534 The encrypted-keys module was using a single global HMAC transform, which could be rekeyed by multiple threads concurrently operating on different keys, causing incorrect HMAC values to be calculated. Fix this by allocating a new HMAC transform whenever we need to calculate a HMAC. Also simplify things a bit by allocating the shash_desc's using SHASH_DESC_ON_STACK() for both the HMAC and unkeyed hashes. The following script reproduces the bug: keyctl new_session keyctl add user master "abcdefghijklmnop" @s for i in $(seq 2); do ( set -e for j in $(seq 1000); do keyid=$(keyctl add encrypted desc$i "new user:master 25" @s) datablob="$(keyctl pipe $keyid)" keyctl unlink $keyid > /dev/null keyid=$(keyctl add encrypted desc$i "load $datablob" @s) keyctl unlink $keyid > /dev/null done ) & done Output with bug: [ 439.691094] encrypted_key: bad hmac (-22) add_key: Invalid argument add_key: Invalid argument Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com> 
The encrypted-keys module was using a single global HMAC transform,
which could be rekeyed by multiple threads concurrently operating on
different keys, causing incorrect HMAC values to be calculated.  Fix
this by allocating a new HMAC transform whenever we need to calculate a
HMAC.  Also simplify things a bit by allocating the shash_desc's using
SHASH_DESC_ON_STACK() for both the HMAC and unkeyed hashes.

The following script reproduces the bug:

    keyctl new_session
    keyctl add user master "abcdefghijklmnop" @s
    for i in $(seq 2); do
        (
            set -e
            for j in $(seq 1000); do
                keyid=$(keyctl add encrypted desc$i "new user:master 25" @s)
                datablob="$(keyctl pipe $keyid)"
                keyctl unlink $keyid > /dev/null
                keyid=$(keyctl add encrypted desc$i "load $datablob" @s)
                keyctl unlink $keyid > /dev/null
            done
        ) &
    done

Output with bug:

    [  439.691094] encrypted_key: bad hmac (-22)
    add_key: Invalid argument
    add_key: Invalid argument

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
KEYS: encrypted: fix buffer overread in valid_master_desc() 2017-06-09T03:29:46+00:00 Eric Biggers ebiggers@google.com 2017-06-08T13:48:18+00:00 794b4bc292f5d31739d89c0202c54e7dc9bc3add With the 'encrypted' key type it was possible for userspace to provide a data blob ending with a master key description shorter than expected, e.g. 'keyctl add encrypted desc "new x" @s'. When validating such a master key description, validate_master_desc() could read beyond the end of the buffer. Fix this by using strncmp() instead of memcmp(). [Also clean up the code to deduplicate some logic.] Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com> 
With the 'encrypted' key type it was possible for userspace to provide a
data blob ending with a master key description shorter than expected,
e.g. 'keyctl add encrypted desc "new x" @s'.  When validating such a
master key description, validate_master_desc() could read beyond the end
of the buffer.  Fix this by using strncmp() instead of memcmp().  [Also
clean up the code to deduplicate some logic.]

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
KEYS: encrypted: avoid encrypting/decrypting stack buffers 2017-06-09T03:29:46+00:00 Eric Biggers ebiggers@google.com 2017-06-08T13:48:10+00:00 e9ff56ac352446f55141aaef1553cee662b2e310 Since v4.9, the crypto API cannot (normally) be used to encrypt/decrypt stack buffers because the stack may be virtually mapped. Fix this for the padding buffers in encrypted-keys by using ZERO_PAGE for the encryption padding and by allocating a temporary heap buffer for the decryption padding. Tested with CONFIG_DEBUG_SG=y: keyctl new_session keyctl add user master "abcdefghijklmnop" @s keyid=$(keyctl add encrypted desc "new user:master 25" @s) datablob="$(keyctl pipe $keyid)" keyctl unlink $keyid keyid=$(keyctl add encrypted desc "load $datablob" @s) datablob2="$(keyctl pipe $keyid)" [ "$datablob" = "$datablob2" ] && echo "Success!" Cc: Andy Lutomirski <luto@kernel.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # 4.9+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com> 
Since v4.9, the crypto API cannot (normally) be used to encrypt/decrypt
stack buffers because the stack may be virtually mapped.  Fix this for
the padding buffers in encrypted-keys by using ZERO_PAGE for the
encryption padding and by allocating a temporary heap buffer for the
decryption padding.

Tested with CONFIG_DEBUG_SG=y:
	keyctl new_session
	keyctl add user master "abcdefghijklmnop" @s
	keyid=$(keyctl add encrypted desc "new user:master 25" @s)
	datablob="$(keyctl pipe $keyid)"
	keyctl unlink $keyid
	keyid=$(keyctl add encrypted desc "load $datablob" @s)
	datablob2="$(keyctl pipe $keyid)"
	[ "$datablob" = "$datablob2" ] && echo "Success!"

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
KEYS: Delete an error message for a failed memory allocation in get_derived_key() 2017-06-09T03:29:46+00:00 Markus Elfring elfring@users.sourceforge.net 2017-06-08T13:47:56+00:00 41f1c53e0d7d6e79087d5f5e18c467747126a3fc Omit an extra message for a memory allocation failure in this function. This issue was detected by using the Coccinelle software. Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com> 
Omit an extra message for a memory allocation failure in this function.

This issue was detected by using the Coccinelle software.

Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>