1. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      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: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  2. 12 Oct, 2017 1 commit
  3. 24 Jun, 2017 1 commit
    • Daniel Walter's avatar
      fscrypt: add support for AES-128-CBC · b7e7cf7a
      Daniel Walter authored
      fscrypt provides facilities to use different encryption algorithms which
      are selectable by userspace when setting the encryption policy. Currently,
      only AES-256-XTS for file contents and AES-256-CBC-CTS for file names are
      implemented. This is a clear case of kernel offers the mechanism and
      userspace selects a policy. Similar to what dm-crypt and ecryptfs have.
      
      This patch adds support for using AES-128-CBC for file contents and
      AES-128-CBC-CTS for file name encryption. To mitigate watermarking
      attacks, IVs are generated using the ESSIV algorithm. While AES-CBC is
      actually slightly less secure than AES-XTS from a security point of view,
      there is more widespread hardware support. Using AES-CBC gives us the
      acceptable performance while still providing a moderate level of security
      for persistent storage.
      
      Especially low-powered embedded devices with crypto accelerators such as
      CAAM or CESA often only support AES-CBC. Since using AES-CBC over AES-XTS
      is basically thought of a last resort, we use AES-128-CBC over AES-256-CBC
      since it has less encryption rounds and yields noticeable better
      performance starting from a file size of just a few kB.
      Signed-off-by: default avatarDaniel Walter <dwalter@sigma-star.at>
      [david@sigma-star.at: addressed review comments]
      Signed-off-by: David Gstir's avatarDavid Gstir <david@sigma-star.at>
      Reviewed-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      b7e7cf7a
  4. 30 Apr, 2017 1 commit
  5. 15 Mar, 2017 1 commit
    • Eric Biggers's avatar
      fscrypt: remove broken support for detecting keyring key revocation · 1b53cf98
      Eric Biggers authored
      Filesystem encryption ostensibly supported revoking a keyring key that
      had been used to "unlock" encrypted files, causing those files to become
      "locked" again.  This was, however, buggy for several reasons, the most
      severe of which was that when key revocation happened to be detected for
      an inode, its fscrypt_info was immediately freed, even while other
      threads could be using it for encryption or decryption concurrently.
      This could be exploited to crash the kernel or worse.
      
      This patch fixes the use-after-free by removing the code which detects
      the keyring key having been revoked, invalidated, or expired.  Instead,
      an encrypted inode that is "unlocked" now simply remains unlocked until
      it is evicted from memory.  Note that this is no worse than the case for
      block device-level encryption, e.g. dm-crypt, and it still remains
      possible for a privileged user to evict unused pages, inodes, and
      dentries by running 'sync; echo 3 > /proc/sys/vm/drop_caches', or by
      simply unmounting the filesystem.  In fact, one of those actions was
      already needed anyway for key revocation to work even somewhat sanely.
      This change is not expected to break any applications.
      
      In the future I'd like to implement a real API for fscrypt key
      revocation that interacts sanely with ongoing filesystem operations ---
      waiting for existing operations to complete and blocking new operations,
      and invalidating and sanitizing key material and plaintext from the VFS
      caches.  But this is a hard problem, and for now this bug must be fixed.
      
      This bug affected almost all versions of ext4, f2fs, and ubifs
      encryption, and it was potentially reachable in any kernel configured
      with encryption support (CONFIG_EXT4_ENCRYPTION=y,
      CONFIG_EXT4_FS_ENCRYPTION=y, CONFIG_F2FS_FS_ENCRYPTION=y, or
      CONFIG_UBIFS_FS_ENCRYPTION=y).  Note that older kernels did not use the
      shared fs/crypto/ code, but due to the potential security implications
      of this bug, it may still be worthwhile to backport this fix to them.
      
      Fixes: b7236e21 ("ext4 crypto: reorganize how we store keys in the inode")
      Cc: stable@vger.kernel.org # v4.2+
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      Acked-by: default avatarMichael Halcrow <mhalcrow@google.com>
      1b53cf98
  6. 01 Mar, 2017 1 commit
    • David Howells's avatar
      KEYS: Differentiate uses of rcu_dereference_key() and user_key_payload() · 0837e49a
      David Howells authored
      rcu_dereference_key() and user_key_payload() are currently being used in
      two different, incompatible ways:
      
       (1) As a wrapper to rcu_dereference() - when only the RCU read lock used
           to protect the key.
      
       (2) As a wrapper to rcu_dereference_protected() - when the key semaphor is
           used to protect the key and the may be being modified.
      
      Fix this by splitting both of the key wrappers to produce:
      
       (1) RCU accessors for keys when caller has the key semaphore locked:
      
      	dereference_key_locked()
      	user_key_payload_locked()
      
       (2) RCU accessors for keys when caller holds the RCU read lock:
      
      	dereference_key_rcu()
      	user_key_payload_rcu()
      
      This should fix following warning in the NFS idmapper
      
        ===============================
        [ INFO: suspicious RCU usage. ]
        4.10.0 #1 Tainted: G        W
        -------------------------------
        ./include/keys/user-type.h:53 suspicious rcu_dereference_protected() usage!
        other info that might help us debug this:
        rcu_scheduler_active = 2, debug_locks = 0
        1 lock held by mount.nfs/5987:
          #0:  (rcu_read_lock){......}, at: [<d000000002527abc>] nfs_idmap_get_key+0x15c/0x420 [nfsv4]
        stack backtrace:
        CPU: 1 PID: 5987 Comm: mount.nfs Tainted: G        W       4.10.0 #1
        Call Trace:
          dump_stack+0xe8/0x154 (unreliable)
          lockdep_rcu_suspicious+0x140/0x190
          nfs_idmap_get_key+0x380/0x420 [nfsv4]
          nfs_map_name_to_uid+0x2a0/0x3b0 [nfsv4]
          decode_getfattr_attrs+0xfac/0x16b0 [nfsv4]
          decode_getfattr_generic.constprop.106+0xbc/0x150 [nfsv4]
          nfs4_xdr_dec_lookup_root+0xac/0xb0 [nfsv4]
          rpcauth_unwrap_resp+0xe8/0x140 [sunrpc]
          call_decode+0x29c/0x910 [sunrpc]
          __rpc_execute+0x140/0x8f0 [sunrpc]
          rpc_run_task+0x170/0x200 [sunrpc]
          nfs4_call_sync_sequence+0x68/0xa0 [nfsv4]
          _nfs4_lookup_root.isra.44+0xd0/0xf0 [nfsv4]
          nfs4_lookup_root+0xe0/0x350 [nfsv4]
          nfs4_lookup_root_sec+0x70/0xa0 [nfsv4]
          nfs4_find_root_sec+0xc4/0x100 [nfsv4]
          nfs4_proc_get_rootfh+0x5c/0xf0 [nfsv4]
          nfs4_get_rootfh+0x6c/0x190 [nfsv4]
          nfs4_server_common_setup+0xc4/0x260 [nfsv4]
          nfs4_create_server+0x278/0x3c0 [nfsv4]
          nfs4_remote_mount+0x50/0xb0 [nfsv4]
          mount_fs+0x74/0x210
          vfs_kern_mount+0x78/0x220
          nfs_do_root_mount+0xb0/0x140 [nfsv4]
          nfs4_try_mount+0x60/0x100 [nfsv4]
          nfs_fs_mount+0x5ec/0xda0 [nfs]
          mount_fs+0x74/0x210
          vfs_kern_mount+0x78/0x220
          do_mount+0x254/0xf70
          SyS_mount+0x94/0x100
          system_call+0x38/0xe0
      Reported-by: default avatarJan Stancek <jstancek@redhat.com>
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Tested-by: default avatarJan Stancek <jstancek@redhat.com>
      Signed-off-by: default avatarJames Morris <james.l.morris@oracle.com>
      0837e49a
  7. 07 Feb, 2017 1 commit
  8. 08 Jan, 2017 1 commit
  9. 02 Jan, 2017 1 commit
    • Theodore Ts'o's avatar
      fscrypt: make test_dummy_encryption require a keyring key · 5bbdcbbb
      Theodore Ts'o authored
      Currently, the test_dummy_encryption ext4 mount option, which exists
      only to test encrypted I/O paths with xfstests, overrides all
      per-inode encryption keys with a fixed key.
      
      This change minimizes test_dummy_encryption-specific code path changes
      by supplying a fake context for directories which are not encrypted
      for use when creating new directories, files, or symlinks.  This
      allows us to properly exercise the keyring lookup, derivation, and
      context inheritance code paths.
      
      Before mounting a file system using test_dummy_encryption, userspace
      must execute the following shell commands:
      
          mode='\x00\x00\x00\x00'
          raw="$(printf ""\\\\x%02x"" $(seq 0 63))"
          if lscpu | grep "Byte Order" | grep -q Little ; then
              size='\x40\x00\x00\x00'
          else
              size='\x00\x00\x00\x40'
          fi
          key="${mode}${raw}${size}"
          keyctl new_session
          echo -n -e "${key}" | keyctl padd logon fscrypt:4242424242424242 @s
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      5bbdcbbb
  10. 28 Dec, 2016 1 commit
    • Theodore Ts'o's avatar
      fscrypt: fix the test_dummy_encryption mount option · fe4f6c80
      Theodore Ts'o authored
      Commit f1c131b4: "crypto: xts - Convert to skcipher" now fails
      the setkey operation if the AES key is the same as the tweak key.
      Previously this check was only done if FIPS mode is enabled.  Now this
      check is also done if weak key checking was requested.  This is
      reasonable, but since we were using the dummy key which was a constant
      series of 0x42 bytes, it now caused dummy encrpyption test mode to
      fail.
      
      Fix this by using 0x42... and 0x24... for the two keys, so they are
      different.
      
      Fixes: f1c131b4
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      fe4f6c80
  11. 11 Dec, 2016 2 commits
  12. 20 Nov, 2016 1 commit
    • Eric Biggers's avatar
      fscrypto: don't use on-stack buffer for key derivation · 0f0909e2
      Eric Biggers authored
      With the new (in 4.9) option to use a virtually-mapped stack
      (CONFIG_VMAP_STACK), stack buffers cannot be used as input/output for
      the scatterlist crypto API because they may not be directly mappable to
      struct page.  get_crypt_info() was using a stack buffer to hold the
      output from the encryption operation used to derive the per-file key.
      Fix it by using a heap buffer.
      
      This bug could most easily be observed in a CONFIG_DEBUG_SG kernel
      because this allowed the BUG in sg_set_buf() to be triggered.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      0f0909e2
  13. 14 Nov, 2016 1 commit
    • Eric Biggers's avatar
      fscrypto: don't use on-stack buffer for key derivation · a6e08912
      Eric Biggers authored
      With the new (in 4.9) option to use a virtually-mapped stack
      (CONFIG_VMAP_STACK), stack buffers cannot be used as input/output for
      the scatterlist crypto API because they may not be directly mappable to
      struct page.  get_crypt_info() was using a stack buffer to hold the
      output from the encryption operation used to derive the per-file key.
      Fix it by using a heap buffer.
      
      This bug could most easily be observed in a CONFIG_DEBUG_SG kernel
      because this allowed the BUG in sg_set_buf() to be triggered.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      a6e08912
  14. 15 Sep, 2016 2 commits
  15. 07 May, 2016 1 commit
    • Jaegeuk Kim's avatar
      fscrypto/f2fs: allow fs-specific key prefix for fs encryption · b5a7aef1
      Jaegeuk Kim authored
      This patch allows fscrypto to handle a second key prefix given by filesystem.
      The main reason is to provide backward compatibility, since previously f2fs
      used "f2fs:" as a crypto prefix instead of "fscrypt:".
      Later, ext4 should also provide key_prefix() to give "ext4:".
      
      One concern decribed by Ted would be kinda double check overhead of prefixes.
      In x86, for example, validate_user_key consumes 8 ms after boot-up, which turns
      out derive_key_aes() consumed most of the time to load specific crypto module.
      After such the cold miss, it shows almost zero latencies, which treats as a
      negligible overhead.
      Note that request_key() detects wrong prefix in prior to derive_key_aes() even.
      
      Cc: Ted Tso <tytso@mit.edu>
      Cc: stable@vger.kernel.org # v4.6
      Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
      b5a7aef1
  16. 18 Mar, 2016 1 commit
    • Jaegeuk Kim's avatar
      fs crypto: move per-file encryption from f2fs tree to fs/crypto · 0b81d077
      Jaegeuk Kim authored
      This patch adds the renamed functions moved from the f2fs crypto files.
      
      1. definitions for per-file encryption used by ext4 and f2fs.
      
      2. crypto.c for encrypt/decrypt functions
       a. IO preparation:
        - fscrypt_get_ctx / fscrypt_release_ctx
       b. before IOs:
        - fscrypt_encrypt_page
        - fscrypt_decrypt_page
        - fscrypt_zeroout_range
       c. after IOs:
        - fscrypt_decrypt_bio_pages
        - fscrypt_pullback_bio_page
        - fscrypt_restore_control_page
      
      3. policy.c supporting context management.
       a. For ioctls:
        - fscrypt_process_policy
        - fscrypt_get_policy
       b. For context permission
        - fscrypt_has_permitted_context
        - fscrypt_inherit_context
      
      4. keyinfo.c to handle permissions
        - fscrypt_get_encryption_info
        - fscrypt_free_encryption_info
      
      5. fname.c to support filename encryption
       a. general wrapper functions
        - fscrypt_fname_disk_to_usr
        - fscrypt_fname_usr_to_disk
        - fscrypt_setup_filename
        - fscrypt_free_filename
      
       b. specific filename handling functions
        - fscrypt_fname_alloc_buffer
        - fscrypt_fname_free_buffer
      
      6. Makefile and Kconfig
      
      Cc: Al Viro <viro@ftp.linux.org.uk>
      Signed-off-by: default avatarMichael Halcrow <mhalcrow@google.com>
      Signed-off-by: default avatarIldar Muslukhov <ildarm@google.com>
      Signed-off-by: default avatarUday Savagaonkar <savagaon@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
      0b81d077
  17. 23 Feb, 2016 3 commits
  18. 27 Jan, 2016 1 commit
  19. 21 Oct, 2015 1 commit
    • David Howells's avatar
      KEYS: Merge the type-specific data with the payload data · 146aa8b1
      David Howells authored
      Merge the type-specific data with the payload data into one four-word chunk
      as it seems pointless to keep them separate.
      
      Use user_key_payload() for accessing the payloads of overloaded
      user-defined keys.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      cc: linux-cifs@vger.kernel.org
      cc: ecryptfs@vger.kernel.org
      cc: linux-ext4@vger.kernel.org
      cc: linux-f2fs-devel@lists.sourceforge.net
      cc: linux-nfs@vger.kernel.org
      cc: ceph-devel@vger.kernel.org
      cc: linux-ima-devel@lists.sourceforge.net
      146aa8b1
  20. 04 Aug, 2015 1 commit
  21. 01 Jun, 2015 4 commits
  22. 28 May, 2015 1 commit