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Stephen Smalley authored
With the sepolicy-analyze neverallow checking, attribute expansion is performed against the device policy and therefore we do not want our neverallow rules to exempt domains from consideration based on an attribute (e.g. -unconfineddomain). Otherwise, device policy could pass the neverallow check just by adding more domains to unconfineddomain. We could of course add a CTS test to check the list of unconfineddomains against a whitelist, but it seems desirable regardless to narrow these neverallow rules to only the specific domains required. There are three such neverallow rules in current policy: one on creating unlabeled files, one on accessing /dev/hw_random, and one on accessing a character device without a specific type. The only domain in unconfineddomain that appears to have a legitimate need for any of these permissions is the init domain. Replace -unconfineddomain with -init in these neverallow rules, exclude these permissions from unconfineddomain, and add these permissions to init if not already explicitly allowed. auditallow accesses by init to files and character devices left in the generic device type so we can monitor what is being left there, although it is not necessarily a problem unless the file or device should be accessible to others. Change-Id: If6ee1b1a337c834971c6eb21dada5810608babcf Signed-off-by:
Stephen Smalley <sds@tycho.nsa.gov>
Stephen Smalley authoredWith the sepolicy-analyze neverallow checking, attribute expansion is performed against the device policy and therefore we do not want our neverallow rules to exempt domains from consideration based on an attribute (e.g. -unconfineddomain). Otherwise, device policy could pass the neverallow check just by adding more domains to unconfineddomain. We could of course add a CTS test to check the list of unconfineddomains against a whitelist, but it seems desirable regardless to narrow these neverallow rules to only the specific domains required. There are three such neverallow rules in current policy: one on creating unlabeled files, one on accessing /dev/hw_random, and one on accessing a character device without a specific type. The only domain in unconfineddomain that appears to have a legitimate need for any of these permissions is the init domain. Replace -unconfineddomain with -init in these neverallow rules, exclude these permissions from unconfineddomain, and add these permissions to init if not already explicitly allowed. auditallow accesses by init to files and character devices left in the generic device type so we can monitor what is being left there, although it is not necessarily a problem unless the file or device should be accessible to others. Change-Id: If6ee1b1a337c834971c6eb21dada5810608babcf Signed-off-by:
Stephen Smalley <sds@tycho.nsa.gov>
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