[PATCH v5 00/21] EVM

Mimi Zohar
2011-05-16T14:46:12Z

Extended Verification Module(EVM) detects offline tampering of the security
extended attributes (e.g. security.selinux, security.SMACK64, security.ima),
which is the basis for LSM permission decisions and, with the IMA-appraisal
patchset, integrity appraisal decisions. This patchset provides the framework
and an initial method to detect offline tampering of the security extended
attributes. The initial method maintains an HMAC-sha1 across a set of
security extended attributes, storing the HMAC as the extended attribute
'security.evm'. To verify the integrity of an extended attribute, EVM exports
evm_verifyxattr(), which re-calculates the HMAC and compares it with the
version stored in 'security.evm'. Other methods of validating the integrity
of a file's metadata will be posted separately (eg. EVM-digital-signatures).

While this patchset does authenticate the security xattrs, and
cryptographically binds them to the inode, coming extensions will bind other
directory and inode metadata for more complete protection. To help simplify
the review and upstreaming process, each extension will be posted separately
(eg. IMA-appraisal, IMA-appraisal-directory). For a general overview of the
proposed Linux integrity subsystem, refer to Dave Safford's whitepaper:
http://downloads.sf.net/project/linux-ima/linux-ima/Integrity_overview.pdf.

Much appreciation to Dave Hansen, Serge Hallyn, and Matt Helsley for
reviewing the original patches.

Changes from v4:
- Added evm_inode_post_init calls for: btrfs, gfs2, jffs2, jfs, and xfs.
- Prevent an invalid security.evm xattr from being updated.
- evm_verifyxattr() performance improvement (Dmitry Kasatkin)
- Fixed evm_verify_hmac() to be fail safe (Dmitry Kasatkin)
- Additional naming change generalizations in preparation for other methods
of integrity authentication. (Dmitry Kasatkin)

Mimi Zohar
David Safford

Dmitry Kasatkin (5):
evm: add support for different security.evm data types
evm: crypto hash replaced by shash
evm: additional parameter to pass integrity cache entry 'iint'
evm: evm_verify_hmac must not return INTEGRITY_UNKNOWN
evm: replace hmac_status with evm_status

Mimi Zohar (16):
integrity: move ima inode integrity data management
xattr: define vfs_getxattr_alloc and vfs_xattr_cmp
evm: re-release
ima: move ima_file_free before releasing the file
security: imbed evm calls in security hooks
evm: evm_inode_post_removexattr
evm: imbed evm_inode_post_setattr
evm: evm_inode_post_init
fs: add evm_inode_post_init calls
evm: add evm_inode_post_init call in btrfs
evm: add evm_inode_post_init call in gfs2
evm: add evm_inode_post_init call in jffs2
evm: add evm_inode_post_init call in jfs
evm: add evm_inode_post_init call in xfs
evm: permit only valid security.evm xattrs to be updated
evm: add evm_inode_setattr to prevent updating an invalid
security.evm

Documentation/ABI/testing/evm | 23 ++
Documentation/kernel-parameters.txt | 6 +
fs/attr.c | 5 +-
fs/btrfs/xattr.c | 39 +++-
fs/ext2/xattr_security.c | 31 +++-
fs/ext3/xattr_security.c | 30 ++-
fs/ext4/xattr_security.c | 30 ++-
fs/file_table.c | 2 +-
fs/gfs2/inode.c | 28 ++-
fs/jffs2/security.c | 26 ++-
fs/jfs/xattr.c | 45 +++--
fs/xattr.c | 63 ++++++-
fs/xfs/linux-2.6/xfs_iops.c | 27 ++-
include/linux/evm.h | 92 +++++++++
include/linux/ima.h | 13 --
include/linux/integrity.h | 43 ++++
include/linux/xattr.h | 14 ++-
security/Kconfig | 2 +-
security/Makefile | 4 +-
security/integrity/Kconfig | 7 +
security/integrity/Makefile | 12 +
security/integrity/evm/Kconfig | 12 +
security/integrity/evm/Makefile | 6 +
security/integrity/evm/evm.h | 39 ++++
security/integrity/evm/evm_crypto.c | 211 +++++++++++++++++++
security/integrity/evm/evm_main.c | 384 +++++++++++++++++++++++++++++++++++
security/integrity/evm/evm_secfs.c | 108 ++++++++++
security/integrity/iint.c | 171 ++++++++++++++++
security/integrity/ima/Kconfig | 1 +
security/integrity/ima/Makefile | 2 +-
security/integrity/ima/ima.h | 29 +--
security/integrity/ima/ima_api.c | 7 +-
security/integrity/ima/ima_iint.c | 169 ---------------
security/integrity/ima/ima_main.c | 12 +-
security/integrity/integrity.h | 38 ++++
security/security.c | 26 ++-
36 files changed, 1465 insertions(+), 292 deletions(-)
create mode 100644 Documentation/ABI/testing/evm
create mode 100644 include/linux/evm.h
create mode 100644 include/linux/integrity.h
create mode 100644 security/integrity/Kconfig
create mode 100644 security/integrity/Makefile
create mode 100644 security/integrity/evm/Kconfig
create mode 100644 security/integrity/evm/Makefile
create mode 100644 security/integrity/evm/evm.h
create mode 100644 security/integrity/evm/evm_crypto.c
create mode 100644 security/integrity/evm/evm_main.c
create mode 100644 security/integrity/evm/evm_secfs.c
create mode 100644 security/integrity/iint.c
delete mode 100644 security/integrity/ima/ima_iint.c
create mode 100644 security/integrity/integrity.h

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1.7.3.4