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2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441Thomas Gleixner1-5/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-04get rid of legacy 'get_ds()' functionLinus Torvalds1-1/+1
Every in-kernel use of this function defined it to KERNEL_DS (either as an actual define, or as an inline function). It's an entirely historical artifact, and long long long ago used to actually read the segment selector valueof '%ds' on x86. Which in the kernel is always KERNEL_DS. Inspired by a patch from Jann Horn that just did this for a very small subset of users (the ones in fs/), along with Al who suggested a script. I then just took it to the logical extreme and removed all the remaining gunk. Roughly scripted with git grep -l '(get_ds())' -- :^tools/ | xargs sed -i 's/(get_ds())/(KERNEL_DS)/' git grep -lw 'get_ds' -- :^tools/ | xargs sed -i '/^#define get_ds()/d' plus manual fixups to remove a few unusual usage patterns, the couple of inline function cases and to fix up a comment that had become stale. The 'get_ds()' function remains in an x86 kvm selftest, since in user space it actually does something relevant. Inspired-by: Jann Horn <jannh@google.com> Inspired-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-13security: audit and remove any unnecessary uses of module.hPaul Gortmaker1-1/+1
Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in removing such instances is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h might have been the implicit source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each instance for the presence of either and replace as needed. Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: John Johansen <john.johansen@canonical.com> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: linux-security-module@vger.kernel.org Cc: linux-integrity@vger.kernel.org Cc: keyrings@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-11LSM: Record LSM name in struct lsm_infoKees Cook1-0/+1
In preparation for making LSM selections outside of the LSMs, include the name of LSMs in struct lsm_info. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-11LSM: Convert security_initcall() into DEFINE_LSM()Kees Cook1-1/+3
Instead of using argument-based initializers, switch to defining the contents of struct lsm_info on a per-LSM basis. This also drops the final use of the now inaccurate "initcall" naming. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <james.morris@microsoft.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-11LSM: Convert from initcall to struct lsm_infoKees Cook1-0/+1
In preparation for doing more interesting LSM init probing, this converts the existing initcall system into an explicit call into a function pointer from a section-collected struct lsm_info array. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <james.morris@microsoft.com> Reviewed-by: John Johansen <john.johansen@canonical.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2018-07-18integrity: silence warning when CONFIG_SECURITYFS is not enabledSudeep Holla1-3/+6
When CONFIG_SECURITYFS is not enabled, securityfs_create_dir returns -ENODEV which throws the following error: "Unable to create integrity sysfs dir: -19" However, if the feature is disabled, it can't be warning and hence we need to silence the error. This patch checks for the error -ENODEV which is returned when CONFIG_SECURITYFS is disabled to stop the error being thrown. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-05-17integrity: Add an integrity directory in securityfsMatthew Garrett1-0/+18
We want to add additional evm control nodes, and it'd be preferable not to clutter up the securityfs root directory any further. Create a new integrity directory, move the ima directory into it, create an evm directory for the evm attribute and add compatibility symlinks. Signed-off-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-23IMA: Support using new creds in appraisal policyMatthew Garrett1-0/+2
The existing BPRM_CHECK functionality in IMA validates against the credentials of the existing process, not any new credentials that the child process may transition to. Add an additional CREDS_CHECK target and refactor IMA to pass the appropriate creds structure. In ima_bprm_check(), check with both the existing process credentials and the credentials that will be committed when the new process is started. This will not change behaviour unless the system policy is extended to include CREDS_CHECK targets - BPRM_CHECK will continue to check the same credentials that it did previously. After this patch, an IMA policy rule along the lines of: measure func=CREDS_CHECK subj_type=unconfined_t will trigger if a process is executed and runs as unconfined_t, ignoring the context of the parent process. This is in contrast to: measure func=BPRM_CHECK subj_type=unconfined_t which will trigger if the process that calls exec() is already executing in unconfined_t, ignoring the context that the child process executes into. Signed-off-by: Matthew Garrett <mjg59@google.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Changelog: - initialize ima_creds_status
2018-02-02ima: re-initialize iint->atomic_flagsMimi Zohar1-0/+1
Intermittently security.ima is not being written for new files. This patch re-initializes the new slab iint->atomic_flags field before freeing it. Fixes: commit 0d73a55208e9 ("ima: re-introduce own integrity cache lock") Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2017-12-18integrity: remove unneeded initializations in integrity_iint_cache entriesJeff Layton1-4/+0
The init_once routine memsets the whole object to 0, and then explicitly sets some of the fields to 0 again. Just remove the explicit initializations. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-12-12ima: re-introduce own integrity cache lockDmitry Kasatkin1-0/+2
Before IMA appraisal was introduced, IMA was using own integrity cache lock along with i_mutex. process_measurement and ima_file_free took the iint->mutex first and then the i_mutex, while setxattr, chmod and chown took the locks in reverse order. To resolve the potential deadlock, i_mutex was moved to protect entire IMA functionality and the redundant iint->mutex was eliminated. Solution was based on the assumption that filesystem code does not take i_mutex further. But when file is opened with O_DIRECT flag, direct-io implementation takes i_mutex and produces deadlock. Furthermore, certain other filesystem operations, such as llseek, also take i_mutex. More recently some filesystems have replaced their filesystem specific lock with the global i_rwsem to read a file. As a result, when IMA attempts to calculate the file hash, reading the file attempts to take the i_rwsem again. To resolve O_DIRECT related deadlock problem, this patch re-introduces iint->mutex. But to eliminate the original chmod() related deadlock problem, this patch eliminates the requirement for chmod hooks to take the iint->mutex by introducing additional atomic iint->attr_flags to indicate calling of the hooks. The allowed locking order is to take the iint->mutex first and then the i_rwsem. Original flags were cleared in chmod(), setxattr() or removwxattr() hooks and tested when file was closed or opened again. New atomic flags are set or cleared in those hooks and tested to clear iint->flags on close or on open. Atomic flags are following: * IMA_CHANGE_ATTR - indicates that chATTR() was called (chmod, chown, chgrp) and file attributes have changed. On file open, it causes IMA to clear iint->flags to re-evaluate policy and perform IMA functions again. * IMA_CHANGE_XATTR - indicates that setxattr or removexattr was called and extended attributes have changed. On file open, it causes IMA to clear iint->flags IMA_DONE_MASK to re-appraise. * IMA_UPDATE_XATTR - indicates that security.ima needs to be updated. It is cleared if file policy changes and no update is needed. * IMA_DIGSIG - indicates that file security.ima has signature and file security.ima must not update to file has on file close. * IMA_MUST_MEASURE - indicates the file is in the measurement policy. Fixes: Commit 6552321831dc ("xfs: remove i_iolock and use i_rwsem in the VFS inode instead") Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08integrity: use kernel_read_file_from_path() to read x509 certsChristoph Hellwig1-49/+0
The CONFIG_IMA_LOAD_X509 and CONFIG_EVM_LOAD_X509 options permit loading x509 signed certificates onto the trusted keyrings without verifying the x509 certificate file's signature. This patch replaces the call to the integrity_read_file() specific function with the common kernel_read_file_from_path() function. To avoid verifying the file signature, this patch defines READING_X509_CERTFICATE. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-06-21integrity: Small code improvementsThiago Jung Bauermann1-1/+1
These changes are too small to warrant their own patches: The keyid and sig_size members of struct signature_v2_hdr are in BE format, so use a type that makes this assumption explicit. Also, use beXX_to_cpu instead of __beXX_to_cpu to read them. Change integrity_kernel_read to take a void * buffer instead of char * buffer, so that callers don't have to use a cast if they provide a buffer that isn't a char *. Add missing #endif comment in ima.h pointing out which macro it refers to. Add missing fall through comment in ima_appraise.c. Constify mask_tokens and func_tokens arrays. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30integrity: add measured_pcrs field to integrity cacheEric Richter1-0/+2
To keep track of which measurements have been extended to which PCRs, this patch defines a new integrity_iint_cache field named measured_pcrs. This field is a bitmask of the PCRs measured. Each bit corresponds to a PCR index. For example, bit 10 corresponds to PCR 10. Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-21ima: remove firmware and module specific cached status infoMimi Zohar1-2/+2
Each time a file is read by the kernel, the file should be re-measured and the file signature re-appraised, based on policy. As there is no need to preserve the status information, this patch replaces the firmware and module specific cache status with a generic one named read_file. This change simplifies adding support for other files read by the kernel. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Petko Manolov <petkan@mip-labs.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2016-01-18Merge branch 'for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: - EVM gains support for loading an x509 cert from the kernel (EVM_LOAD_X509), into the EVM trusted kernel keyring. - Smack implements 'file receive' process-based permission checking for sockets, rather than just depending on inode checks. - Misc enhancments for TPM & TPM2. - Cleanups and bugfixes for SELinux, Keys, and IMA. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (41 commits) selinux: Inode label revalidation performance fix KEYS: refcount bug fix ima: ima_write_policy() limit locking IMA: policy can be updated zero times selinux: rate-limit netlink message warnings in selinux_nlmsg_perm() selinux: export validatetrans decisions gfs2: Invalid security labels of inodes when they go invalid selinux: Revalidate invalid inode security labels security: Add hook to invalidate inode security labels selinux: Add accessor functions for inode->i_security security: Make inode argument of inode_getsecid non-const security: Make inode argument of inode_getsecurity non-const selinux: Remove unused variable in selinux_inode_init_security keys, trusted: seal with a TPM2 authorization policy keys, trusted: select hash algorithm for TPM2 chips keys, trusted: fix: *do not* allow duplicate key options tpm_ibmvtpm: properly handle interrupted packet receptions tpm_tis: Tighten IRQ auto-probing tpm_tis: Refactor the interrupt setup tpm_tis: Get rid of the duplicate IRQ probing code ...
2016-01-04fix the leak in integrity_read_file()Al Viro1-5/+6
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-15evm: load an x509 certificate from the kernelDmitry Kasatkin1-0/+1
This patch defines a configuration option and the evm_load_x509() hook to load an X509 certificate onto the EVM trusted kernel keyring. Changes in v4: * Patch description updated Changes in v3: * Removed EVM_X509_PATH definition. CONFIG_EVM_X509_PATH is used directly. Changes in v2: * default key patch changed to /etc/keys Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-05-21integrity: add validity checks for 'path' parameterDmitry Kasatkin1-0/+3
This patch adds validity checks for 'path' parameter and makes it const. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-18VFS: refactor vfs_read()Dmitry Kasatkin1-7/+3
integrity_kernel_read() duplicates the file read operations code in vfs_read(). This patch refactors vfs_read() code creating a helper function __vfs_read(). It is used by both vfs_read() and integrity_kernel_read(). Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-18integrity: provide a hook to load keys when rootfs is readyDmitry Kasatkin1-0/+11
Keys can only be loaded once the rootfs is mounted. Initcalls are not suitable for that. This patch defines a special hook to load the x509 public keys onto the IMA keyring, before attempting to access any file. The keys are required for verifying the file's signature. The hook is called after the root filesystem is mounted and before the kernel calls 'init'. Changes in v3: * added more explanation to the patch description (Mimi) Changes in v2: * Hook renamed as 'integrity_load_keys()' to handle both IMA and EVM keys by integrity subsystem. * Hook patch moved after defining loading functions Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-18integrity: define a new function integrity_read_file()Dmitry Kasatkin1-0/+78
This patch defines a new function called integrity_read_file() to read file from the kernel into a buffer. Subsequent patches will read a file containing the public keys and load them onto the IMA keyring. This patch moves and renames ima_kernel_read(), the non-security checking version of kernel_read(), to integrity_kernel_read(). Changes in v3: * Patch descriptions improved (Mimi) * Add missing cast (kbuild test robot) Changes in v2: * configuration option removed * function declared as '__init' Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-07ima: check ima_policy_flag in the ima_file_free() hookDmitry Kasatkin1-3/+0
This patch completes the switching to the 'ima_policy_flag' variable in the checks at the beginning of IMA functions, starting with the commit a756024e. Checking 'iint_initialized' is completely unnecessary, because S_IMA flag is unset if iint was not allocated. At the same time the integrity cache is allocated with SLAB_PANIC and the kernel will panic if the allocation fails during kernel initialization. So on a running system iint_initialized is always true and can be removed. Changes in v3: * not limiting test to IMA_APPRAISE (spotted by Roberto Sassu) Changes in v2: * 'iint_initialized' removal patch merged to this patch (requested by Mimi) Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Acked-by: Roberto Sassu <roberto.sassu@polito.it>
2014-03-07integrity: fix checkpatch errorsDmitry Kasatkin1-1/+1
Between checkpatch changes (eg. sizeof) and inconsistencies between Lindent and checkpatch, unfixed checkpatch errors make it difficult to see new errors. This patch fixes them. Some lines with over 80 chars remained unchanged to improve code readability. The "extern" keyword is removed from internal evm.h to make it consistent with internal ima.h. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-26ima: use dynamically allocated hash storageDmitry Kasatkin1-0/+2
For each inode in the IMA policy, an iint is allocated. To support larger hash digests, the iint digest size changed from 20 bytes to the maximum supported hash digest size. Instead of allocating the maximum size, which most likely is not needed, this patch dynamically allocates the needed hash storage. Changelog: - fix krealloc bug Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-01-23ima: per hook cache integrity appraisal statusMimi Zohar1-2/+8
With the new IMA policy 'appraise_type=' option, different hooks can require different methods for appraising a file's integrity. For example, the existing 'ima_appraise_tcb' policy defines a generic rule, requiring all root files to be appraised, without specfying the appraisal method. A more specific rule could require all kernel modules, for example, to be signed. appraise fowner=0 func=MODULE_CHECK appraise_type=imasig appraise fowner=0 As a result, the integrity appraisal results for the same inode, but for different hooks, could differ. This patch caches the integrity appraisal results on a per hook basis. Changelog v2: - Rename ima_cache_status() to ima_set_cache_status() - Rename and move get_appraise_status() to ima_get_cache_status() Changelog v0: - include IMA_APPRAISE/APPRAISED_SUBMASK in IMA_DO/DONE_MASK (Dmitry) - Support independent MODULE_CHECK appraise status. - fixed IMA_XXXX_APPRAISE/APPRAISED flags Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2012-09-07ima: replace iint spinblock with rwlock/read_lockDmitry Kasatkin1-9/+7
For performance, replace the iint spinlock with rwlock/read_lock. Eric Paris questioned this change, from spinlocks to rwlocks, saying "rwlocks have been shown to actually be slower on multi processor systems in a number of cases due to the cache line bouncing required." Based on performance measurements compiling the kernel on a cold boot with multiple jobs with/without this patch, Dmitry Kasatkin and I found that rwlocks performed better than spinlocks, but very insignificantly. For example with total compilation time around 6 minutes, with rwlocks time was 1 - 3 seconds shorter... but always like that. Changelog v2: - new patch taken from the 'allocating iint improvements' patch Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2012-09-07ima: allocating iint improvementsDmitry Kasatkin1-26/+19
With IMA-appraisal's removal of the iint mutex and taking the i_mutex instead, allocating the iint becomes a lot simplier, as we don't need to be concerned with two processes racing to allocate the iint. This patch cleans up and improves performance for allocating the iint. - removed redundant double i_mutex locking - combined iint allocation with tree search Changelog v2: - removed the rwlock/read_lock changes from this patch Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2012-09-07ima: integrity appraisal extensionMimi Zohar1-1/+2
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. This patch creates and maintains the 'security.ima' xattr, containing the file data hash measurement. Protection of the xattr is provided by EVM, if enabled and configured. Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata integrity and, assuming success, compares the file's current hash value with the one stored as an extended attribute in 'security.ima'. Changelov v4: - changed iint cache flags to hex values Changelog v3: - change appraisal default for filesystems without xattr support to fail Changelog v2: - fix audit msg 'res' value - removed unused 'ima_appraise=' values Changelog v1: - removed unused iint mutex (Dmitry Kasatkin) - setattr hook must not reset appraised (Dmitry Kasatkin) - evm_verifyxattr() now differentiates between no 'security.evm' xattr (INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the 'security.evm' (INTEGRITY_NOXATTRS). - replace hash_status with ima_status (Dmitry Kasatkin) - re-initialize slab element ima_status on free (Dmitry Kasatkin) - include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA - merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin) - removed unnecessary error variable in process_measurement() (Dmitry Kasatkin) - use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured (moved ima_inode_post_setattr() to ima_appraise.c) - make sure ima_collect_measurement() can read file Changelog: - add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin) - fix the race condition between chmod, which takes the i_mutex and then iint->mutex, and ima_file_free() and process_measurement(), which take the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin) - cleanup of ima_appraise_measurement() (Dmitry Kasatkin) - changes as a result of the iint not allocated for all regular files, but only for those measured/appraised. - don't try to appraise new/empty files - expanded ima_appraisal description in ima/Kconfig - IMA appraise definitions required even if IMA_APPRAISE not enabled - add return value to ima_must_appraise() stub - unconditionally set status = INTEGRITY_PASS *after* testing status, not before. (Found by Joe Perches) Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
2011-09-14evm: clean verification statusDmitry Kasatkin1-0/+1
When allocating from slab, initialization is done the first time in init_once() and subsequently on free. Because evm_status was not re-initialized on free, evm_verify_hmac() skipped verifications. This patch re-initializes evm_status. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-07-18evm: replace hmac_status with evm_statusDmitry Kasatkin1-1/+1
We will use digital signatures in addtion to hmac. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-07-18evm: re-releaseMimi Zohar1-0/+1
EVM protects a file's security extended attributes(xattrs) against integrity attacks. This patchset provides the framework and an initial method. The initial method maintains an HMAC-sha1 value across the security extended attributes, storing the HMAC value as the extended attribute '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. EVM depends on the Kernel Key Retention System to provide it with a trusted/encrypted key for the HMAC-sha1 operation. The key is loaded onto the root's keyring using keyctl. Until EVM receives notification that the key has been successfully loaded onto the keyring (echo 1 > <securityfs>/evm), EVM can not create or validate the 'security.evm' xattr, but returns INTEGRITY_UNKNOWN. Loading the key and signaling EVM should be done as early as possible. Normally this is done in the initramfs, which has already been measured as part of the trusted boot. For more information on creating and loading existing trusted/encrypted keys, refer to Documentation/keys-trusted-encrypted.txt. A sample dracut patch, which loads the trusted/encrypted key and enables EVM, is available from http://linux-ima.sourceforge.net/#EVM. Based on the LSMs enabled, the set of EVM protected security xattrs is defined at compile. EVM adds the following three calls to the existing security hooks: evm_inode_setxattr(), evm_inode_post_setxattr(), and evm_inode_removexattr. To initialize and update the 'security.evm' extended attribute, EVM defines three calls: evm_inode_post_init(), evm_inode_post_setattr() and evm_inode_post_removexattr() hooks. To verify the integrity of a security xattr, EVM exports evm_verifyxattr(). Changelog v7: - Fixed URL in EVM ABI documentation Changelog v6: (based on Serge Hallyn's review) - fix URL in patch description - remove evm_hmac_size definition - use SHA1_DIGEST_SIZE (removed both MAX_DIGEST_SIZE and evm_hmac_size) - moved linux include before other includes - test for crypto_hash_setkey failure - fail earlier for invalid key - clear entire encrypted key, even on failure - check xattr name length before comparing xattr names Changelog: - locking based on i_mutex, remove evm_mutex - using trusted/encrypted keys for storing the EVM key used in the HMAC-sha1 operation. - replaced crypto hash with shash (Dmitry Kasatkin) - support for additional methods of verifying the security xattrs (Dmitry Kasatkin) - iint not allocated for all regular files, but only for those appraised - Use cap_sys_admin in lieu of cap_mac_admin - Use __vfs_setxattr_noperm(), without permission checks, from EVM Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
2011-07-18integrity: move ima inode integrity data managementMimi Zohar1-0/+170
Move the inode integrity data(iint) management up to the integrity directory in order to share the iint among the different integrity models. Changelog: - don't define MAX_DIGEST_SIZE - rename several globally visible 'ima_' prefixed functions, structs, locks, etc to 'integrity_' - replace '20' with SHA1_DIGEST_SIZE - reflect location change in appropriate Kconfig and Makefiles - remove unnecessary initialization of iint_initialized to 0 - rebased on current ima_iint.c - define integrity_iint_store/lock as static There should be no other functional changes. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>