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authorTushar Sugandhi <tusharsu@linux.microsoft.com>2021-07-12 17:48:58 -0700
committerMike Snitzer <snitzer@redhat.com>2021-08-10 13:32:40 -0400
commit91ccbbac1747eea155632a1c6bb100052309b215 (patch)
treeeb0fd0c79d6e90100da2c75fc86699e45f1e6c70 /security
parente3a35d03407cb3ef9488835aa861e07b45638d0b (diff)
downloadlinux-91ccbbac1747eea155632a1c6bb100052309b215.tar.gz
dm ima: measure data on table load
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>
Diffstat (limited to 'security')
-rw-r--r--security/integrity/ima/ima_main.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 287b90509006..673833f94069 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -985,6 +985,7 @@ void ima_measure_critical_data(const char *event_label,
CRITICAL_DATA, 0, event_label,
hash);
}
+EXPORT_SYMBOL_GPL(ima_measure_critical_data);
static int __init init_ima(void)
{