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 -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
