kernel.git/drivers/md/dm-ioctl.c, branch linux-5.16.y

dm ioctl: prevent potential spectre v1 gadget

2022-04-13T18:03:03Z

[ Upstream commit cd9c88da171a62c4b0f1c70e50c75845969fbc18 ] It appears like cmd could be a Spectre v1 gadget as it's supplied by a user and used as an array index. Prevent the contents of kernel memory from being leaked to userspace via speculative execution by using array_index_nospec. Signed-off-by: Jordy Zomer Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin

dm ima: measure data on device rename

2021-08-10T17:34:23Z

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 Signed-off-by: Mike Snitzer

dm ima: measure data on table clear

2021-08-10T17:34:23Z

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 Signed-off-by: Mike Snitzer

dm ima: measure data on device remove

2021-08-10T17:34:22Z

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 Signed-off-by: Mike Snitzer

dm ima: measure data on device resume

2021-08-10T17:34:22Z

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 Signed-off-by: Mike Snitzer

dm ima: measure data on table load

2021-08-10T17:32:40Z

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 Signed-off-by: Colin Ian King # leak fix Signed-off-by: Mike Snitzer

dm: move setting md->type into dm_setup_md_queue

2021-08-09T17:50:43Z

Move setting md->type from both callers into dm_setup_md_queue. This ensures that md->type is only set to a valid value after the queue has been fully setup, something we'll rely on future changes. Signed-off-by: Christoph Hellwig Reviewed-by: Mike Snitzer Link: https://lore.kernel.org/r/20210804094147.459763-7-hch@lst.de Signed-off-by: Jens Axboe

dm ioctl: filter the returned values according to name or uuid prefix

2021-03-26T18:53:41Z

If we set non-empty param->name or param->uuid on the DM_LIST_DEVICES_CMD ioctl, the set values are considered filter prefixes. The ioctl will only return entries with matching name or uuid prefix. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm ioctl: return UUID in DM_LIST_DEVICES_CMD result

2021-03-26T18:53:41Z

When LVM needs to find a device with a particular UUID it needs to ask for UUID for each device. This patch returns UUID directly in the list of devices, so that LVM doesn't have to query all the devices with an ioctl. The UUID is returned if the flag DM_UUID_FLAG is set in the parameters. Returning UUID is done in backward-compatible way. There's one unused 32-bit word value after the event number. This patch sets the bit DM_NAME_LIST_FLAG_HAS_UUID if UUID is present and DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID if it isn't (if none of these bits is set, then we have an old kernel that doesn't support returning UUIDs). The UUID is stored after this word. The 'next' value is updated to point after the UUID, so that old version of libdevmapper will skip the UUID without attempting to interpret it. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm ioctl: replace device hash with red-black tree

2021-03-26T18:53:41Z

For high numbers of DM devices the 64-entry hash table has non-trivial overhead. Fix this by replacing the hash table with a red-black tree. Reported-by: Zdenek Kabelac Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer