lkml.org 
[lkml]   [2012]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Subject[PATCH v3 00/12] ima: appraisal extension
    Date
    IMA currently maintains an integrity measurement list used to assert the
    integrity of the running system to a third party. The IMA-appraisal
    extension adds local integrity validation and enforcement of the
    measurement against a "good" value stored as an extended attribute
    'security.ima'. The initial methods for validating 'security.ima' are
    hashed based, which provides file data integrity, and digital signature
    based, which in addition to providing file data integrity, provides
    authenticity.

    New hooks:
    ima_inode_setxattr(), ima_inode_removexattr(), ima_inode_post_setattr(),
    and ima_defer_fput()

    IMA-appraisal extends the measurement policy ABI with two new keywords:
    appraise/dont_appraise and adds a new boot parameter 'ima_appraise_tcb'
    to appraise all files owned by root. Like the ima_tcb measurement policy,
    the ima_appraise_tcb policy does not appraise pseudo filesystem files
    (eg. debugfs, tmpfs, securityfs, selinuxfs or ramfs.)

    Additional rules can be added to the default IMA measurement/appraisal
    policy, which take advantage of the SELinux labels, for a more fine
    grained policy.

    Locking changes:

    The ima-appraisal extension maintains the file integrity measurement as
    an extended attribute 'security.ima'. ima_file_free(), called on __fput(),
    updates 'security.ima' to reflect any changes made to the file. In fix
    mode, process_measurement() writes 'security.ima' to reflect the current
    file hash. Writing extended attributes and other file metadata (eg. chmod),
    requires taking the i_mutex. Both ima_file_free() and process_measurement()
    took the iint->mutex and then the i_mutex, while chmod() took the locks in
    reverse order. To resolve the potential lock inversion deadlock, the
    redundant iint->mutex was eliminated.

    Writing 'security.ima' from __fput() caused an mmap_sem/i_mutex lockdep,
    when an mmapped file was closed before it was munmapped. To resolve this
    lockdep, ima_defer_fput() defers the __fput, by incrementing the f_count
    and creating/adding it to the workqueue.

    Prereqs:
    vfs: fix IMA lockdep circular locking dependency
    vfs: iversion truncate bug fix

    Changelog v3:
    - defined the boot command line parameter 'ima_appraise_tcb' to permit
    measuring without appraising, and appraising without measuring.
    - use slab mempool to defer __fput() work
    - change appraisal default for filesystems without xattr support to fail

    Changelog v2:
    - Split the "ima: allocating iint improvements" patch, making the
    spinlock to rwlock/read_lock change into a separate patch.
    - Removed the "vfs: Correctly set the dir i_mutex lockdep class" dependency.
    - New: "ima: delay calling __fput()"
    - Minor changes listed in individual patch descriptions

    Changelog v1:
    - Initial posting of the IMA-appraisal patches, separately from EVM.

    Mimi

    Dmitry Kasatkin (3):
    ima: free securityfs violations file
    ima: allocating iint improvements
    ima: digital signature verification support

    Mimi Zohar (9):
    vfs: extend vfs_removexattr locking
    vfs: move ima_file_free before releasing the file
    ima: integrity appraisal extension
    ima: add appraise action keywords and default rules
    ima: replace iint spinlock with rwlock/read_lock
    ima: add inode_post_setattr call
    ima: add ima_inode_setxattr/removexattr function and calls
    ima: defer calling __fput()
    ima: add support for different security.ima data types

    Documentation/ABI/testing/ima_policy | 25 ++-
    Documentation/kernel-parameters.txt | 8 +
    fs/attr.c | 2 +
    fs/file_table.c | 2 +-
    fs/xattr.c | 6 +-
    include/linux/ima.h | 32 +++
    include/linux/integrity.h | 7 +-
    include/linux/xattr.h | 3 +
    mm/mmap.c | 1 +
    security/integrity/evm/evm_main.c | 3 +
    security/integrity/iint.c | 64 +++----
    security/integrity/ima/Kconfig | 15 ++
    security/integrity/ima/Makefile | 2 +
    security/integrity/ima/ima.h | 37 ++++-
    security/integrity/ima/ima_api.c | 56 ++++--
    security/integrity/ima/ima_appraise.c | 347 +++++++++++++++++++++++++++++++++
    security/integrity/ima/ima_crypto.c | 8 +-
    security/integrity/ima/ima_fs.c | 1 +
    security/integrity/ima/ima_main.c | 89 ++++++---
    security/integrity/ima/ima_policy.c | 181 +++++++++++++-----
    security/integrity/integrity.h | 11 +-
    security/security.c | 6 +
    22 files changed, 757 insertions(+), 149 deletions(-)
    create mode 100644 security/integrity/ima/ima_appraise.c

    --
    1.7.6.5



    \
     
     \ /
      Last update: 2012-03-21 20:03    [W:0.027 / U:0.172 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site