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
      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>
  2. 06 Jul, 2017 1 commit
    • Tahsin Erdogan's avatar
      ext4: fix __ext4_new_inode() journal credits calculation · af65207c
      Tahsin Erdogan authored
      ea_inode feature allows creating extended attributes that are up to
      64k in size. Update __ext4_new_inode() to pick increased credit limits.
      To avoid overallocating too many journal credits, update
      __ext4_xattr_set_credits() to make a distinction between xattr create
      vs update. This helps __ext4_new_inode() because all attributes are
      known to be new, so we can save credits that are normally needed to
      delete old values.
      Also, have fscrypt specify its maximum context size so that we don't
      end up allocating credits for 64k size.
      Signed-off-by: default avatarTahsin Erdogan <tahsin@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
  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>
  4. 04 May, 2017 1 commit
    • Eric Biggers's avatar
      fscrypt: fix context consistency check when key(s) unavailable · 272f98f6
      Eric Biggers authored
      To mitigate some types of offline attacks, filesystem encryption is
      designed to enforce that all files in an encrypted directory tree use
      the same encryption policy (i.e. the same encryption context excluding
      the nonce).  However, the fscrypt_has_permitted_context() function which
      enforces this relies on comparing struct fscrypt_info's, which are only
      available when we have the encryption keys.  This can cause two
      incorrect behaviors:
      1. If we have the parent directory's key but not the child's key, or
         vice versa, then fscrypt_has_permitted_context() returned false,
         causing applications to see EPERM or ENOKEY.  This is incorrect if
         the encryption contexts are in fact consistent.  Although we'd
         normally have either both keys or neither key in that case since the
         master_key_descriptors would be the same, this is not guaranteed
         because keys can be added or removed from keyrings at any time.
      2. If we have neither the parent's key nor the child's key, then
         fscrypt_has_permitted_context() returned true, causing applications
         to see no error (or else an error for some other reason).  This is
         incorrect if the encryption contexts are in fact inconsistent, since
         in that case we should deny access.
      To fix this, retrieve and compare the fscrypt_contexts if we are unable
      to set up both fscrypt_infos.
      While this slightly hurts performance when accessing an encrypted
      directory tree without the key, this isn't a case we really need to be
      optimizing for; access *with* the key is much more important.
      Furthermore, the performance hit is barely noticeable given that we are
      already retrieving the fscrypt_context and doing two keyring searches in
      fscrypt_get_encryption_info().  If we ever actually wanted to optimize
      this case we might start by caching the fscrypt_contexts.
      Cc: stable@vger.kernel.org # 4.0+
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
  5. 30 Apr, 2017 1 commit
  6. 15 Mar, 2017 1 commit
    • Eric Biggers's avatar
      fscrypt: eliminate ->prepare_context() operation · 94840e3c
      Eric Biggers authored
      The only use of the ->prepare_context() fscrypt operation was to allow
      ext4 to evict inline data from the inode before ->set_context().
      However, there is no reason why this cannot be done as simply the first
      step in ->set_context(), and in fact it makes more sense to do it that
      way because then the policy modes and flags get validated before any
      real work is done.  Therefore, merge ext4_prepare_context() into
      ext4_set_context(), and remove ->prepare_context().
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
  7. 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:
          raw="$(printf ""\\\\x%02x"" $(seq 0 63))"
          if lscpu | grep "Byte Order" | grep -q Little ; then
          keyctl new_session
          echo -n -e "${key}" | keyctl padd logon fscrypt:4242424242424242 @s
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
  8. 31 Dec, 2016 5 commits
    • Eric Biggers's avatar
      fscrypt: pass up error codes from ->get_context() · efee590e
      Eric Biggers authored
      It was possible for the ->get_context() operation to fail with a
      specific error code, which was then not returned to the caller of
      to pass through these error codes.  Also reorganize the code so that
      ->get_context() only needs to be called one time when setting an
      encryption policy, and handle contexts of unrecognized sizes more
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
    • Eric Biggers's avatar
      fscrypt: remove user-triggerable warning messages · 868e1bc6
      Eric Biggers authored
      Several warning messages were not rate limited and were user-triggerable
      from FS_IOC_SET_ENCRYPTION_POLICY.  These shouldn't really have been
      there in the first place, but either way they aren't as useful now that
      the error codes have been improved.  So just remove them.
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
    • Eric Biggers's avatar
      fscrypt: use EEXIST when file already uses different policy · 8488cd96
      Eric Biggers authored
      As part of an effort to clean up fscrypt-related error codes, make
      FS_IOC_SET_ENCRYPTION_POLICY fail with EEXIST when the file already uses
      a different encryption policy.  This is more descriptive than EINVAL,
      which was ambiguous with some of the other error cases.
      I am not aware of any users who might be relying on the previous error
      code of EINVAL, which was never documented anywhere.
      This failure case will be exercised by an xfstest.
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
    • Eric Biggers's avatar
      fscrypt: use ENOTDIR when setting encryption policy on nondirectory · dffd0cfa
      Eric Biggers authored
      As part of an effort to clean up fscrypt-related error codes, make
      FS_IOC_SET_ENCRYPTION_POLICY fail with ENOTDIR when the file descriptor
      does not refer to a directory.  This is more descriptive than EINVAL,
      which was ambiguous with some of the other error cases.
      I am not aware of any users who might be relying on the previous error
      code of EINVAL, which was never documented anywhere, and in some buggy
      kernels did not exist at all as the S_ISDIR() check was missing.
      This failure case will be exercised by an xfstest.
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
    • Eric Biggers's avatar
      fscrypt: fix renaming and linking special files · 42d97eb0
      Eric Biggers authored
      Attempting to link a device node, named pipe, or socket file into an
      encrypted directory through rename(2) or link(2) always failed with
      EPERM.  This happened because fscrypt_has_permitted_context() saw that
      the file was unencrypted and forbid creating the link.  This behavior
      was unexpected because such files are never encrypted; only regular
      files, directories, and symlinks can be encrypted.
      To fix this, make fscrypt_has_permitted_context() always return true on
      special files.
      This will be covered by a test in my encryption xfstests patchset.
      Fixes: 9bd8212f ("ext4 crypto: add encryption policy and password salt support")
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Reviewed-by: Richard Weinberger's avatarRichard Weinberger <richard@nod.at>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
  9. 11 Dec, 2016 2 commits
  10. 15 Oct, 2016 1 commit
  11. 10 Sep, 2016 3 commits
    • Eric Biggers's avatar
      fscrypto: require write access to mount to set encryption policy · ba63f23d
      Eric Biggers authored
      Since setting an encryption policy requires writing metadata to the
      filesystem, it should be guarded by mnt_want_write/mnt_drop_write.
      Otherwise, a user could cause a write to a frozen or readonly
      filesystem.  This was handled correctly by f2fs but not by ext4.  Make
      fscrypt_process_policy() handle it rather than relying on the filesystem
      to get it right.
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Cc: stable@vger.kernel.org # 4.1+; check fs/{ext4,f2fs}
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      Acked-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
    • Eric Biggers's avatar
      fscrypto: only allow setting encryption policy on directories · 002ced4b
      Eric Biggers authored
      The FS_IOC_SET_ENCRYPTION_POLICY ioctl allowed setting an encryption
      policy on nondirectory files.  This was unintentional, and in the case
      of nonempty regular files did not behave as expected because existing
      data was not actually encrypted by the ioctl.
      In the case of ext4, the user could also trigger filesystem errors in
      ->empty_dir(), e.g. due to mismatched "directory" checksums when the
      kernel incorrectly tried to interpret a regular file as a directory.
      This bug affected ext4 with kernels v4.8-rc1 or later and f2fs with
      kernels v4.6 and later.  It appears that older kernels only permitted
      directories and that the check was accidentally lost during the
      refactoring to share the file encryption code between ext4 and f2fs.
      This patch restores the !S_ISDIR() check that was present in older
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
    • Eric Biggers's avatar
      fscrypto: add authorization check for setting encryption policy · 163ae1c6
      Eric Biggers authored
      On an ext4 or f2fs filesystem with file encryption supported, a user
      could set an encryption policy on any empty directory(*) to which they
      had readonly access.  This is obviously problematic, since such a
      directory might be owned by another user and the new encryption policy
      would prevent that other user from creating files in their own directory
      (for example).
      Fix this by requiring inode_owner_or_capable() permission to set an
      encryption policy.  This means that either the caller must own the file,
      or the caller must have the capability CAP_FOWNER.
      (*) Or also on any regular file, for f2fs v4.6 and later and ext4
          v4.8-rc1 and later; a separate bug fix is coming for that.
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Cc: stable@vger.kernel.org # 4.1+; check fs/{ext4,f2fs}
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
  12. 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>