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Message-Id: <1277403031-3080-1-git-send-email-zohar@linux.vnet.ibm.com> Date: Thu, 24 Jun 2010 14:10:16 -0400 From: Mimi Zohar <zohar@...ux.vnet.ibm.com> To: linux-kernel@...r.kernel.org Cc: Mimi Zohar <zohar@...ux.vnet.ibm.com>, linux-security-module@...r.kernel.org, linux-fsdevel@...r.kernel.org, James Morris <jmorris@...ei.org>, David Safford <safford@...son.ibm.com>, Dave Hansen <dave@...ux.vnet.ibm.com> Subject: [PATCH 00/15] EVM The EVM patches were previously posted on LSM/LKML. Am reposting them here, as well as on fs-devel for comments and review. fs summary: - Moves ima_iint.c up a layer to security/integrity and renames ima_inode_alloc/free hooks to integrity_inode_alloc/free - Defines 2 new generic functions: vfs_getxattr_alloc, vfs_xattr_cmp - Adds 3 EVM calls in the security hooks: evm_inode_setxattr(), evm_inode_post_setxattr(), evm_inode_removexattr - Defines 3 new calls: evm_inode_post_init(), evm_inode_post_setattr(), evm_inode_post_removexattr() - Exports: evm_verifyxattr() - Defines 3 new IMA calls for IMA appraisal: ima_inode_setxattr(), ima_inode_removexattr(), and ima_inode_post_setattr() To address concerns of exposing the EVM key to userspace in plaintext (Eric Paris, Stephan Smalley), future work will define new key-types for use with TPM sealed keys and encrypted symmetric keys, so that on systems with a TPM, the EVM key will never be visible outside the kernel in plaintext form. 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 this set of patches, integrity appraisal decisions. To detect offline tampering of the extended attributes, EVM 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'. IMA currently maintains an integrity measurement list, containing the hashes of all executables, mmapped execute files, and files open for read by root (assuming the default measurement policy). The measurement list, with other information, can be used to assert the integrity of the running system to a third party. The "ima: integrity appraisal extension" patch extends IMA with local measurement appraisal. The extension stores and maintains the file integrity measurement as an extended attribute 'security.ima', which EVM can be configured to protect. DAC/MAC protect the integrity of a running system. An offline attack can bypass these protection mechanisms by mounting the disk under a different operating system and modifying the file data/metadata. If the disk is subsequently remounted under the EVM + DAC/MAC + IMA protected OS, then the hash of the file data won't match the hash stored in the IMA xattr, or the TPM-calculated HMAC of the file's metadata won't be valid. Therefore, IMA + MAC + EVM can protect system integrity online and detect offline tampering. This patch set applies to the security-testing/next tree. For more information on IMA/EVM, refer to http://linux-ima.sourceforge.net/#EVM. Much appreciation to Dave Hansen, Serge Hallyn, and Matt Helsley for reviewing the patches. Mimi Mimi Zohar (15): integrity: move ima inode integrity data management security: move LSM xattrnames to xattr.h 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: inode post removexattr evm: imbed evm_inode_post_setattr evm: inode_post_init fs: add evm_inode_post_init calls ima: integrity appraisal extension ima: appraise default rules ima: inode post_setattr ima: add ima_inode_setxattr and ima_inode_removexattr ima: appraise measurement required Documentation/kernel-parameters.txt | 4 + fs/attr.c | 7 +- fs/ext2/xattr_security.c | 31 +++- fs/ext3/xattr_security.c | 30 +++- fs/ext4/xattr_security.c | 30 +++- fs/file_table.c | 2 +- fs/xattr.c | 63 ++++++- include/linux/capability.h | 3 - include/linux/evm.h | 80 ++++++++ include/linux/ima.h | 27 ++- include/linux/integrity.h | 35 ++++ include/linux/xattr.h | 27 +++- security/Kconfig | 2 +- security/Makefile | 4 +- security/integrity/Kconfig | 7 + security/integrity/Makefile | 12 ++ security/integrity/evm/Kconfig | 13 ++ security/integrity/evm/Makefile | 7 + security/integrity/evm/evm.h | 38 ++++ security/integrity/evm/evm_crypto.c | 198 +++++++++++++++++++ security/integrity/evm/evm_main.c | 335 +++++++++++++++++++++++++++++++++ security/integrity/evm/evm_secfs.c | 108 +++++++++++ security/integrity/iint.c | 153 +++++++++++++++ security/integrity/ima/Kconfig | 15 ++ security/integrity/ima/Makefile | 4 +- security/integrity/ima/ima.h | 76 +++++--- security/integrity/ima/ima_api.c | 61 +++++-- security/integrity/ima/ima_appraise.c | 151 +++++++++++++++ security/integrity/ima/ima_iint.c | 146 -------------- security/integrity/ima/ima_main.c | 152 +++++++++++++--- security/integrity/ima/ima_policy.c | 61 ++++++- security/integrity/integrity.h | 50 +++++ security/security.c | 27 +++- security/selinux/hooks.c | 3 - security/smack/smack.h | 2 - 35 files changed, 1699 insertions(+), 265 deletions(-) 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 create mode 100644 security/integrity/ima/ima_appraise.c delete mode 100644 security/integrity/ima/ima_iint.c create mode 100644 security/integrity/integrity.h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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