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* Merge tag 'integrity-v5.15' of ↵Linus Torvalds2021-09-021-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull integrity subsystem updates from Mimi Zohar: - Limit the allowed hash algorithms when writing security.ima xattrs or verifying them, based on the IMA policy and the configured hash algorithms. - Return the calculated "critical data" measurement hash and size to avoid code duplication. (Preparatory change for a proposed LSM.) - and a single patch to address a compiler warning. * tag 'integrity-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: IMA: reject unknown hash algorithms in ima_get_hash_algo IMA: prevent SETXATTR_CHECK policy rules with unavailable algorithms IMA: introduce a new policy option func=SETXATTR_CHECK IMA: add a policy option to restrict xattr hash algorithms on appraisal IMA: add support to restrict the hash algorithms used for file appraisal IMA: block writes of the security.ima xattr with unsupported algorithms IMA: remove the dependency on CRYPTO_MD5 ima: Add digest and digest_len params to the functions to measure a buffer ima: Return int in the functions to measure a buffer ima: Introduce ima_get_current_hash_algo() IMA: remove -Wmissing-prototypes warning
* dm ima: prefix ima event name related to device mapper with dm_Tushar Sugandhi2021-08-201-9/+10
| | | | | | | | | | | | The event names for the DM events recorded in the ima log do not contain any information to indicate the events are part of the DM devices/targets. Prefix the event names for DM events with "dm_" to indicate that they are part of device-mapper. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Suggested-by: Thore Sommer <public@thson.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm ima: add version info to dm related events in ima logTushar Sugandhi2021-08-201-12/+48
| | | | | | | | | | | | | | | | The DM events present in the ima log contain various attributes in the key=value format. The attributes' names/values may change in future, and new attributes may also get added. The attestation server needs some versioning to determine which attributes are supported and are expected in the ima log. Add version information to the DM events present in the ima log to help attestation servers to correctly process the attributes across different versions. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Suggested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm ima: prefix dm table hashes in ima log with hash algorithmTushar Sugandhi2021-08-201-3/+11
| | | | | | | | | | | | | | The active/inactive table hashes measured in the ima log do not contain the information about hash algorithm. This information is useful for the attestation servers to recreate the hashes and compare them with the ones present in the ima log to verify the table contents. Prefix the table hashes in various DM events in ima log with the hash algorithm used to compute those hashes. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Suggested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm ima: measure data on device renameTushar Sugandhi2021-08-101-0/+48
| | | | | | | | | | | | | | A given block device is identified by it's name and UUID. However, both these parameters can be renamed. For an external attestation service to correctly attest a given device, it needs to keep track of these rename events. Update the device data with the new values for IMA measurements. Measure both old and new device name/UUID parameters in the same IMA measurement event, so that the old and the new values can be connected later. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm ima: measure data on table clearTushar Sugandhi2021-08-101-0/+92
| | | | | | | | | | | | | | For a given block device, an inactive table slot contains the parameters to configure the device with. The inactive table can be cleared multiple times, accidentally or maliciously, which may impact the functionality of the device, and compromise the system. Therefore it is important to measure and log the event when a table is cleared. Measure device parameters, and table hashes when the inactive table slot is cleared. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm ima: measure data on device removeTushar Sugandhi2021-08-101-0/+119
| | | | | | | | | | | | | Presence of an active block-device, configured with expected parameters, is important for an external attestation service to determine if a system meets the attestation requirements. Therefore it is important for DM to measure the device remove events. Measure device parameters and table hashes when the device is removed, using either remove or remove_all. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm ima: measure data on device resumeTushar Sugandhi2021-08-101-0/+116
| | | | | | | | | | | | | | | | | | | | A given block device can load a table multiple times, with different input parameters, before eventually resuming it. Further, a device may be suspended and then resumed. The device may never resume after a table-load. Because of the above valid scenarios for a given device, it is important to measure and log the device resume event using IMA. Also, if the table is large, measuring it in clear-text each time the device changes state, will unnecessarily increase the size of IMA log. Since the table clear-text is already measured during table-load event, measuring the hash during resume should be sufficient to validate the table contents. Measure the device parameters, and hash of the active table, when the device is resumed. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm ima: measure data on table loadTushar Sugandhi2021-08-101-0/+330
DM configures a block device with various target specific attributes passed to it as a table. DM loads the table, and calls each target’s respective constructors with the attributes as input parameters. Some of these attributes are critical to ensure the device meets certain security bar. Thus, IMA should measure these attributes, to ensure they are not tampered with, during the lifetime of the device. So that the external services can have high confidence in the configuration of the block-devices on a given system. Some devices may have large tables. And a given device may change its state (table-load, suspend, resume, rename, remove, table-clear etc.) many times. Measuring these attributes each time when the device changes its state will significantly increase the size of the IMA logs. Further, once configured, these attributes are not expected to change unless a new table is loaded, or a device is removed and recreated. Therefore the clear-text of the attributes should only be measured during table load, and the hash of the active/inactive table should be measured for the remaining device state changes. Export IMA function ima_measure_critical_data() to allow measurement of DM device parameters, as well as target specific attributes, during table load. Compute the hash of the inactive table and store it for measurements during future state change. If a load is called multiple times, update the inactive table hash with the hash of the latest populated table. So that the correct inactive table hash is measured when the device transitions to different states like resume, remove, rename, etc. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # leak fix Signed-off-by: Mike Snitzer <snitzer@redhat.com>