linux/security/integrity/ima/ima.h

611 lines
19 KiB

ima: new templates management mechanism The original 'ima' template is fixed length, containing the filedata hash and pathname. The filedata hash is limited to 20 bytes (md5/sha1). The pathname is a null terminated string, limited to 255 characters. To overcome these limitations and to add additional file metadata, it is necessary to extend the current version of IMA by defining additional templates. The main reason to introduce this feature is that, each time a new template is defined, the functions that generate and display the measurement list would include the code for handling a new format and, thus, would significantly grow over time. This patch set solves this problem by separating the template management from the remaining IMA code. The core of this solution is the definition of two new data structures: a template descriptor, to determine which information should be included in the measurement list, and a template field, to generate and display data of a given type. To define a new template field, developers define the field identifier and implement two functions, init() and show(), respectively to generate and display measurement entries. Initially, this patch set defines the following template fields (support for additional data types will be added later):  - 'd': the digest of the event (i.e. the digest of a measured file),         calculated with the SHA1 or MD5 hash algorithm;  - 'n': the name of the event (i.e. the file name), with size up to         255 bytes;  - 'd-ng': the digest of the event, calculated with an arbitrary hash            algorithm (field format: [<hash algo>:]digest, where the digest            prefix is shown only if the hash algorithm is not SHA1 or MD5);  - 'n-ng': the name of the event, without size limitations. Defining a new template descriptor requires specifying the template format, a string of field identifiers separated by the '|' character. This patch set defines the following template descriptors:  - "ima": its format is 'd|n';  - "ima-ng" (default): its format is 'd-ng|n-ng' Further details about the new template architecture can be found in Documentation/security/IMA-templates.txt. Changelog: - don't defer calling ima_init_template() - Mimi - don't define ima_lookup_template_desc() until used - Mimi - squashed with documentation patch - Mimi Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-06-07 12:16:29 +02:00
ima: add crypto agility support for template-hash algorithm The template hash showed by the ascii_runtime_measurements and binary_runtime_measurements is the one calculated using sha1 and there is no possibility to change this value, despite the fact that the template hash is calculated using the hash algorithms corresponding to all the PCR banks configured in the TPM. Add the support to retrieve the ima log with the template data hash calculated with a specific hash algorithm. Add a new file in the securityfs ima directory for each hash algo configured in a PCR bank of the TPM. Each new file has the name with the following structure: {binary, ascii}_runtime_measurements_<hash_algo_name> Legacy files are kept, to avoid breaking existing applications, but as symbolic links which point to {binary, ascii}_runtime_measurements_sha1 files. These two files are created even if a TPM chip is not detected or the sha1 bank is not configured in the TPM. As example, in the case a TPM chip is present and sha256 is the only configured PCR bank, the listing of the securityfs ima directory is the following: lr--r--r-- [...] ascii_runtime_measurements -> ascii_runtime_measurements_sha1 -r--r----- [...] ascii_runtime_measurements_sha1 -r--r----- [...] ascii_runtime_measurements_sha256 lr--r--r-- [...] binary_runtime_measurements -> binary_runtime_measurements_sha1 -r--r----- [...] binary_runtime_measurements_sha1 -r--r----- [...] binary_runtime_measurements_sha256 --w------- [...] policy -r--r----- [...] runtime_measurements_count -r--r----- [...] violations Signed-off-by: Enrico Bravi <enrico.bravi@polito.it> Signed-off-by: Silvia Sisinni <silvia.sisinni@polito.it> Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2024-04-12 11:09:53 +02:00
ima: add crypto agility support for template-hash algorithm The template hash showed by the ascii_runtime_measurements and binary_runtime_measurements is the one calculated using sha1 and there is no possibility to change this value, despite the fact that the template hash is calculated using the hash algorithms corresponding to all the PCR banks configured in the TPM. Add the support to retrieve the ima log with the template data hash calculated with a specific hash algorithm. Add a new file in the securityfs ima directory for each hash algo configured in a PCR bank of the TPM. Each new file has the name with the following structure: {binary, ascii}_runtime_measurements_<hash_algo_name> Legacy files are kept, to avoid breaking existing applications, but as symbolic links which point to {binary, ascii}_runtime_measurements_sha1 files. These two files are created even if a TPM chip is not detected or the sha1 bank is not configured in the TPM. As example, in the case a TPM chip is present and sha256 is the only configured PCR bank, the listing of the securityfs ima directory is the following: lr--r--r-- [...] ascii_runtime_measurements -> ascii_runtime_measurements_sha1 -r--r----- [...] ascii_runtime_measurements_sha1 -r--r----- [...] ascii_runtime_measurements_sha256 lr--r--r-- [...] binary_runtime_measurements -> binary_runtime_measurements_sha1 -r--r----- [...] binary_runtime_measurements_sha1 -r--r----- [...] binary_runtime_measurements_sha256 --w------- [...] policy -r--r----- [...] runtime_measurements_count -r--r----- [...] violations Signed-off-by: Enrico Bravi <enrico.bravi@polito.it> Signed-off-by: Silvia Sisinni <silvia.sisinni@polito.it> Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2024-04-12 11:09:53 +02:00
ima: add crypto agility support for template-hash algorithm The template hash showed by the ascii_runtime_measurements and binary_runtime_measurements is the one calculated using sha1 and there is no possibility to change this value, despite the fact that the template hash is calculated using the hash algorithms corresponding to all the PCR banks configured in the TPM. Add the support to retrieve the ima log with the template data hash calculated with a specific hash algorithm. Add a new file in the securityfs ima directory for each hash algo configured in a PCR bank of the TPM. Each new file has the name with the following structure: {binary, ascii}_runtime_measurements_<hash_algo_name> Legacy files are kept, to avoid breaking existing applications, but as symbolic links which point to {binary, ascii}_runtime_measurements_sha1 files. These two files are created even if a TPM chip is not detected or the sha1 bank is not configured in the TPM. As example, in the case a TPM chip is present and sha256 is the only configured PCR bank, the listing of the securityfs ima directory is the following: lr--r--r-- [...] ascii_runtime_measurements -> ascii_runtime_measurements_sha1 -r--r----- [...] ascii_runtime_measurements_sha1 -r--r----- [...] ascii_runtime_measurements_sha256 lr--r--r-- [...] binary_runtime_measurements -> binary_runtime_measurements_sha1 -r--r----- [...] binary_runtime_measurements_sha1 -r--r----- [...] binary_runtime_measurements_sha256 --w------- [...] policy -r--r----- [...] runtime_measurements_count -r--r----- [...] violations Signed-off-by: Enrico Bravi <enrico.bravi@polito.it> Signed-off-by: Silvia Sisinni <silvia.sisinni@polito.it> Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2024-04-12 11:09:53 +02:00
ima: integrity appraisal extension 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>
2012-02-13 10:15:05 -05:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: new templates management mechanism The original 'ima' template is fixed length, containing the filedata hash and pathname. The filedata hash is limited to 20 bytes (md5/sha1). The pathname is a null terminated string, limited to 255 characters. To overcome these limitations and to add additional file metadata, it is necessary to extend the current version of IMA by defining additional templates. The main reason to introduce this feature is that, each time a new template is defined, the functions that generate and display the measurement list would include the code for handling a new format and, thus, would significantly grow over time. This patch set solves this problem by separating the template management from the remaining IMA code. The core of this solution is the definition of two new data structures: a template descriptor, to determine which information should be included in the measurement list, and a template field, to generate and display data of a given type. To define a new template field, developers define the field identifier and implement two functions, init() and show(), respectively to generate and display measurement entries. Initially, this patch set defines the following template fields (support for additional data types will be added later):  - 'd': the digest of the event (i.e. the digest of a measured file),         calculated with the SHA1 or MD5 hash algorithm;  - 'n': the name of the event (i.e. the file name), with size up to         255 bytes;  - 'd-ng': the digest of the event, calculated with an arbitrary hash            algorithm (field format: [<hash algo>:]digest, where the digest            prefix is shown only if the hash algorithm is not SHA1 or MD5);  - 'n-ng': the name of the event, without size limitations. Defining a new template descriptor requires specifying the template format, a string of field identifiers separated by the '|' character. This patch set defines the following template descriptors:  - "ima": its format is 'd|n';  - "ima-ng" (default): its format is 'd-ng|n-ng' Further details about the new template architecture can be found in Documentation/security/IMA-templates.txt. Changelog: - don't defer calling ima_init_template() - Mimi - don't define ima_lookup_template_desc() until used - Mimi - squashed with documentation patch - Mimi Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-06-07 12:16:29 +02:00
ima: new templates management mechanism The original 'ima' template is fixed length, containing the filedata hash and pathname. The filedata hash is limited to 20 bytes (md5/sha1). The pathname is a null terminated string, limited to 255 characters. To overcome these limitations and to add additional file metadata, it is necessary to extend the current version of IMA by defining additional templates. The main reason to introduce this feature is that, each time a new template is defined, the functions that generate and display the measurement list would include the code for handling a new format and, thus, would significantly grow over time. This patch set solves this problem by separating the template management from the remaining IMA code. The core of this solution is the definition of two new data structures: a template descriptor, to determine which information should be included in the measurement list, and a template field, to generate and display data of a given type. To define a new template field, developers define the field identifier and implement two functions, init() and show(), respectively to generate and display measurement entries. Initially, this patch set defines the following template fields (support for additional data types will be added later):  - 'd': the digest of the event (i.e. the digest of a measured file),         calculated with the SHA1 or MD5 hash algorithm;  - 'n': the name of the event (i.e. the file name), with size up to         255 bytes;  - 'd-ng': the digest of the event, calculated with an arbitrary hash            algorithm (field format: [<hash algo>:]digest, where the digest            prefix is shown only if the hash algorithm is not SHA1 or MD5);  - 'n-ng': the name of the event, without size limitations. Defining a new template descriptor requires specifying the template format, a string of field identifiers separated by the '|' character. This patch set defines the following template descriptors:  - "ima": its format is 'd|n';  - "ima-ng" (default): its format is 'd-ng|n-ng' Further details about the new template architecture can be found in Documentation/security/IMA-templates.txt. Changelog: - don't defer calling ima_init_template() - Mimi - don't define ima_lookup_template_desc() until used - Mimi - squashed with documentation patch - Mimi Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-06-07 12:16:29 +02:00
ima: new templates management mechanism The original 'ima' template is fixed length, containing the filedata hash and pathname. The filedata hash is limited to 20 bytes (md5/sha1). The pathname is a null terminated string, limited to 255 characters. To overcome these limitations and to add additional file metadata, it is necessary to extend the current version of IMA by defining additional templates. The main reason to introduce this feature is that, each time a new template is defined, the functions that generate and display the measurement list would include the code for handling a new format and, thus, would significantly grow over time. This patch set solves this problem by separating the template management from the remaining IMA code. The core of this solution is the definition of two new data structures: a template descriptor, to determine which information should be included in the measurement list, and a template field, to generate and display data of a given type. To define a new template field, developers define the field identifier and implement two functions, init() and show(), respectively to generate and display measurement entries. Initially, this patch set defines the following template fields (support for additional data types will be added later):  - 'd': the digest of the event (i.e. the digest of a measured file),         calculated with the SHA1 or MD5 hash algorithm;  - 'n': the name of the event (i.e. the file name), with size up to         255 bytes;  - 'd-ng': the digest of the event, calculated with an arbitrary hash            algorithm (field format: [<hash algo>:]digest, where the digest            prefix is shown only if the hash algorithm is not SHA1 or MD5);  - 'n-ng': the name of the event, without size limitations. Defining a new template descriptor requires specifying the template format, a string of field identifiers separated by the '|' character. This patch set defines the following template descriptors:  - "ima": its format is 'd|n';  - "ima-ng" (default): its format is 'd-ng|n-ng' Further details about the new template architecture can be found in Documentation/security/IMA-templates.txt. Changelog: - don't defer calling ima_init_template() - Mimi - don't define ima_lookup_template_desc() until used - Mimi - squashed with documentation patch - Mimi Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-06-07 12:16:29 +02:00
ima: new templates management mechanism The original 'ima' template is fixed length, containing the filedata hash and pathname. The filedata hash is limited to 20 bytes (md5/sha1). The pathname is a null terminated string, limited to 255 characters. To overcome these limitations and to add additional file metadata, it is necessary to extend the current version of IMA by defining additional templates. The main reason to introduce this feature is that, each time a new template is defined, the functions that generate and display the measurement list would include the code for handling a new format and, thus, would significantly grow over time. This patch set solves this problem by separating the template management from the remaining IMA code. The core of this solution is the definition of two new data structures: a template descriptor, to determine which information should be included in the measurement list, and a template field, to generate and display data of a given type. To define a new template field, developers define the field identifier and implement two functions, init() and show(), respectively to generate and display measurement entries. Initially, this patch set defines the following template fields (support for additional data types will be added later):  - 'd': the digest of the event (i.e. the digest of a measured file),         calculated with the SHA1 or MD5 hash algorithm;  - 'n': the name of the event (i.e. the file name), with size up to         255 bytes;  - 'd-ng': the digest of the event, calculated with an arbitrary hash            algorithm (field format: [<hash algo>:]digest, where the digest            prefix is shown only if the hash algorithm is not SHA1 or MD5);  - 'n-ng': the name of the event, without size limitations. Defining a new template descriptor requires specifying the template format, a string of field identifiers separated by the '|' character. This patch set defines the following template descriptors:  - "ima": its format is 'd|n';  - "ima-ng" (default): its format is 'd-ng|n-ng' Further details about the new template architecture can be found in Documentation/security/IMA-templates.txt. Changelog: - don't defer calling ima_init_template() - Mimi - don't define ima_lookup_template_desc() until used - Mimi - squashed with documentation patch - Mimi Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-06-07 12:16:29 +02:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Move to LSM infrastructure Move hardcoded IMA function calls (not appraisal-specific functions) from various places in the kernel to the LSM infrastructure, by introducing a new LSM named 'ima' (at the end of the LSM list and always enabled like 'integrity'). Having IMA before EVM in the Makefile is sufficient to preserve the relative order of the new 'ima' LSM in respect to the upcoming 'evm' LSM, and thus the order of IMA and EVM function calls as when they were hardcoded. Make moved functions as static (except ima_post_key_create_or_update(), which is not in ima_main.c), and register them as implementation of the respective hooks in the new function init_ima_lsm(). Select CONFIG_SECURITY_PATH, to ensure that the path-based LSM hook path_post_mknod is always available and ima_post_path_mknod() is always executed to mark files as new, as before the move. A slight difference is that IMA and EVM functions registered for the inode_post_setattr, inode_post_removexattr, path_post_mknod, inode_post_create_tmpfile, inode_post_set_acl and inode_post_remove_acl won't be executed for private inodes. Since those inodes are supposed to be fs-internal, they should not be of interest to IMA or EVM. The S_PRIVATE flag is used for anonymous inodes, hugetlbfs, reiserfs xattrs, XFS scrub and kernel-internal tmpfs files. Conditionally register ima_post_key_create_or_update() if CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled. Also, conditionally register ima_kernel_module_request() if CONFIG_INTEGRITY_ASYMMETRIC_KEYS is enabled. Finally, add the LSM_ID_IMA case in lsm_list_modules_test.c. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Acked-by: Chuck Lever <chuck.lever@oracle.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:08 +01:00
ima: measure kexec load and exec events as critical data The amount of memory allocated at kexec load, even with the extra memory allocated, might not be large enough for the entire measurement list. The indeterminate interval between kexec 'load' and 'execute' could exacerbate this problem. Define two new IMA events, 'kexec_load' and 'kexec_execute', to be measured as critical data at kexec 'load' and 'execute' respectively. Report the allocated kexec segment size, IMA binary log size and the runtime measurements count as part of those events. These events, and the values reported through them, serve as markers in the IMA log to verify the IMA events are captured during kexec soft reboot. The presence of a 'kexec_load' event in between the last two 'boot_aggregate' events in the IMA log implies this is a kexec soft reboot, and not a cold-boot. And the absence of 'kexec_execute' event after kexec soft reboot implies missing events in that window which results in inconsistency with TPM PCR quotes, necessitating a cold boot for a successful remote attestation. These critical data events are displayed as hex encoded ascii in the ascii_runtime_measurement_list. Verifying the critical data hash requires calculating the hash of the decoded ascii string. For example, to verify the 'kexec_load' data hash: sudo cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements | grep kexec_load | cut -d' ' -f 6 | xxd -r -p | sha256sum To verify the 'kexec_execute' data hash: sudo cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements | grep kexec_execute | cut -d' ' -f 6 | xxd -r -p | sha256sum Co-developed-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Steven Chen <chenste@linux.microsoft.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Acked-by: Baoquan He <bhe@redhat.com> Tested-by: Stefan Berger <stefanb@linux.ibm.com> # ppc64/kvm Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2025-04-21 15:25:15 -07:00
ima: define a canonical binary_runtime_measurements list format The IMA binary_runtime_measurements list is currently in platform native format. To allow restoring a measurement list carried across kexec with a different endianness than the targeted kernel, this patch defines little-endian as the canonical format. For big endian systems wanting to save/restore the measurement list from a system with a different endianness, a new boot command line parameter named "ima_canonical_fmt" is defined. Considerations: use of the "ima_canonical_fmt" boot command line option will break existing userspace applications on big endian systems expecting the binary_runtime_measurements list to be in platform native format. Link: http://lkml.kernel.org/r/1480554346-29071-10-git-send-email-zohar@linux.vnet.ibm.com Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andreas Steffen <andreas.steffen@strongswan.org> Cc: Josh Sklar <sklar@linux.vnet.ibm.com> Cc: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-19 16:22:57 -08:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Suspend PCR extends and log appends when rebooting To avoid the following types of error messages due to a failure by the TPM driver to use the TPM, suspend TPM PCR extensions and the appending of entries to the IMA log once IMA's reboot notifier has been called. This avoids trying to use the TPM after the TPM subsystem has been shut down. [111707.685315][ T1] ima: Error Communicating to TPM chip, result: -19 [111707.685960][ T1] ima: Error Communicating to TPM chip, result: -19 Synchronization with the ima_extend_list_mutex to set ima_measurements_suspended ensures that the TPM subsystem is not shut down when IMA holds the mutex while appending to the log and extending the PCR. The alternative of reading the system_state variable would not provide this guarantee. This error could be observed on a ppc64 machine running SuSE Linux where processes are still accessing files after devices have been shut down. Suspending the IMA log and PCR extensions shortly before reboot does not seem to open a significant measurement gap since neither TPM quoting would work for attestation nor that new log entries could be written to anywhere after devices have been shut down. However, there's a time window between the invocation of the reboot notifier and the shutdown of devices. This includes all subsequently invoked reboot notifiers as well as kernel_restart_prepare() where __usermodehelper_disable() waits for all running_helpers to exit. During this time window IMA could now miss log entries even though attestation would still work. The reboot of the system shortly after may make this small gap insignificant. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2024-11-18 09:57:31 -05:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: integrity appraisal extension 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>
2012-02-13 10:15:05 -05:00
ima: integrity appraisal extension 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>
2012-02-13 10:15:05 -05:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Check against blacklisted hashes for files with modsig Asymmetric private keys are used to sign multiple files. The kernel currently supports checking against blacklisted keys. However, if the public key is blacklisted, any file signed by the blacklisted key will automatically fail signature verification. Blacklisting the public key is not fine enough granularity, as we might want to only blacklist a particular file. This patch adds support for checking against the blacklisted hash of the file, without the appended signature, based on the IMA policy. It defines a new policy option "appraise_flag=check_blacklist". In addition to the blacklisted binary hashes stored in the firmware "dbx" variable, the Linux kernel may be configured to load blacklisted binary hashes onto the .blacklist keyring as well. The following example shows how to blacklist a specific kernel module hash. $ sha256sum kernel/kheaders.ko 77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 kernel/kheaders.ko $ grep BLACKLIST .config CONFIG_SYSTEM_BLACKLIST_KEYRING=y CONFIG_SYSTEM_BLACKLIST_HASH_LIST="blacklist-hash-list" $ cat certs/blacklist-hash-list "bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3" Update the IMA custom measurement and appraisal policy rules (/etc/ima-policy): measure func=MODULE_CHECK template=ima-modsig appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig After building, installing, and rebooting the kernel: 545660333 ---lswrv 0 0 \_ blacklist: bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 measure func=MODULE_CHECK template=ima-modsig appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig modprobe: ERROR: could not insert 'kheaders': Permission denied 10 0c9834db5a0182c1fb0cdc5d3adcf11a11fd83dd ima-sig sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40 2 /usr/lib/modules/5.4.0-rc3+/kernel/kernel/kheaders.ko 10 82aad2bcc3fa8ed94762356b5c14838f3bcfa6a0 ima-modsig sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40 2 /usr/lib/modules/5.4.0rc3+/kernel/kernel/kheaders.ko sha256:77fa889b3 5a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 3082029a06092a864886f70d010702a082028b30820287020101310d300b0609608648 016503040201300b06092a864886f70d01070131820264.... 10 25b72217cc1152b44b134ce2cd68f12dfb71acb3 ima-buf sha256:8b58427fedcf8f4b20bc8dc007f2e232bf7285d7b93a66476321f9c2a3aa132 b blacklisted-hash 77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 Signed-off-by: Nayna Jain <nayna@linux.ibm.com> [zohar@linux.ibm.com: updated patch description] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1572492694-6520-8-git-send-email-zohar@linux.ibm.com
2019-10-30 23:31:32 -04:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: integrity appraisal extension 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>
2012-02-13 10:15:05 -05:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: Check against blacklisted hashes for files with modsig Asymmetric private keys are used to sign multiple files. The kernel currently supports checking against blacklisted keys. However, if the public key is blacklisted, any file signed by the blacklisted key will automatically fail signature verification. Blacklisting the public key is not fine enough granularity, as we might want to only blacklist a particular file. This patch adds support for checking against the blacklisted hash of the file, without the appended signature, based on the IMA policy. It defines a new policy option "appraise_flag=check_blacklist". In addition to the blacklisted binary hashes stored in the firmware "dbx" variable, the Linux kernel may be configured to load blacklisted binary hashes onto the .blacklist keyring as well. The following example shows how to blacklist a specific kernel module hash. $ sha256sum kernel/kheaders.ko 77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 kernel/kheaders.ko $ grep BLACKLIST .config CONFIG_SYSTEM_BLACKLIST_KEYRING=y CONFIG_SYSTEM_BLACKLIST_HASH_LIST="blacklist-hash-list" $ cat certs/blacklist-hash-list "bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3" Update the IMA custom measurement and appraisal policy rules (/etc/ima-policy): measure func=MODULE_CHECK template=ima-modsig appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig After building, installing, and rebooting the kernel: 545660333 ---lswrv 0 0 \_ blacklist: bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 measure func=MODULE_CHECK template=ima-modsig appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig modprobe: ERROR: could not insert 'kheaders': Permission denied 10 0c9834db5a0182c1fb0cdc5d3adcf11a11fd83dd ima-sig sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40 2 /usr/lib/modules/5.4.0-rc3+/kernel/kernel/kheaders.ko 10 82aad2bcc3fa8ed94762356b5c14838f3bcfa6a0 ima-modsig sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40 2 /usr/lib/modules/5.4.0rc3+/kernel/kernel/kheaders.ko sha256:77fa889b3 5a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 3082029a06092a864886f70d010702a082028b30820287020101310d300b0609608648 016503040201300b06092a864886f70d01070131820264.... 10 25b72217cc1152b44b134ce2cd68f12dfb71acb3 ima-buf sha256:8b58427fedcf8f4b20bc8dc007f2e232bf7285d7b93a66476321f9c2a3aa132 b blacklisted-hash 77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 Signed-off-by: Nayna Jain <nayna@linux.ibm.com> [zohar@linux.ibm.com: updated patch description] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1572492694-6520-8-git-send-email-zohar@linux.ibm.com
2019-10-30 23:31:32 -04:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: integrity appraisal extension 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>
2012-02-13 10:15:05 -05:00
ima: integrity appraisal extension 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>
2012-02-13 10:15:05 -05:00
ima: integrity appraisal extension 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>
2012-02-13 10:15:05 -05:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: integrity appraisal extension 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>
2012-02-13 10:15:05 -05:00
ima: Make it independent from 'integrity' LSM Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-02-15 11:31:12 +01:00
ima: integrity appraisal extension 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>
2012-02-13 10:15:05 -05:00
ima: Avoid blocking in RCU read-side critical section A panic happens in ima_match_policy: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 PGD 42f873067 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 5 PID: 1286325 Comm: kubeletmonit.sh Kdump: loaded Tainted: P Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:ima_match_policy+0x84/0x450 Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39 7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea 44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f RSP: 0018:ff71570009e07a80 EFLAGS: 00010207 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200 RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739 R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970 R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001 FS: 00007f5195b51740(0000) GS:ff3e278b12d40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ima_get_action+0x22/0x30 process_measurement+0xb0/0x830 ? page_add_file_rmap+0x15/0x170 ? alloc_set_pte+0x269/0x4c0 ? prep_new_page+0x81/0x140 ? simple_xattr_get+0x75/0xa0 ? selinux_file_open+0x9d/0xf0 ima_file_check+0x64/0x90 path_openat+0x571/0x1720 do_filp_open+0x9b/0x110 ? page_counter_try_charge+0x57/0xc0 ? files_cgroup_alloc_fd+0x38/0x60 ? __alloc_fd+0xd4/0x250 ? do_sys_open+0x1bd/0x250 do_sys_open+0x1bd/0x250 do_syscall_64+0x5d/0x1d0 entry_SYSCALL_64_after_hwframe+0x65/0xca Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a RCU read-side critical section which contains kmalloc with GFP_KERNEL. This implies a possible sleep and violates limitations of RCU read-side critical sections on non-PREEMPT systems. Sleeping within RCU read-side critical section might cause synchronize_rcu() returning early and break RCU protection, allowing a UAF to happen. The root cause of this issue could be described as follows: | Thread A | Thread B | | |ima_match_policy | | | rcu_read_lock | |ima_lsm_update_rule | | | synchronize_rcu | | | | kmalloc(GFP_KERNEL)| | | sleep | ==> synchronize_rcu returns early | kfree(entry) | | | | entry = entry->next| ==> UAF happens and entry now becomes NULL (or could be anything). | | entry->action | ==> Accessing entry might cause panic. To fix this issue, we are converting all kmalloc that is called within RCU read-side critical section to use GFP_ATOMIC. Fixes: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") Cc: stable@vger.kernel.org Signed-off-by: GUO Zihua <guozihua@huawei.com> Acked-by: John Johansen <john.johansen@canonical.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> [PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case] Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-05-07 01:25:41 +00:00