Re: Unique audit record type ranges for individual LSMs

On 12/6/2017 9:51 AM, Tyler Hicks wrote: > Hello - The AppArmor project would like for AppArmor audit records to be > supported by the audit-userspace tools, such as ausearch, but it > requires some coordination between the linux-security-module and > linux-audit lists. This was raised as a feature request years ago in > Ubuntu and more recently in Debian: > > https://launchpad.net/bugs/1117804 > https://bugs.debian.org/872726 > > The quick summary of the problem at hand is that the audit-userspace > project requires that each LSM use a unique record type range for audit > records while the kernel's common_lsm_audit() function uses the same > record type (1400) for all records. SELinux, AppArmor, and SMACK are all > using common_lsm_audit() today and, therefore, the 1400-1499 range. My, but this is a rat's nest, isn't it? The constants, such as AUDIT_MAC_STATUS, look as if they are intended to be generic. But the comment says the range is for SELinux. Some of the events, including AUDIT_MAC_MAP_ADD *are* generic, in that they are from the netlbl subsystem. But some, AUDIT_AVC being paramount, are indeed SELinux specific.

> While it will be potentially painful to switch, the AppArmor project is > considering to use a unique range in order for audit-userspace to > support AppArmor audit records. IMHO, SMACK would be free to continue > using 1400-1499 as long as they don't need audit-userspace support and > SELinux would continue using 1400-1499. Aside from the comment that says 1400-1499 are for SELinux, and the three events (1400-1402) that are SELinux specific, the events really are general. Why not add the AppArmor specifics to the 1400 range? Give them a generic sounding name and you'll achieve consistency. Change the comment to say "Security Module use" instead of "SELinux use".

> Steve Grubb previously told me that he intends 1500-1599 to be used by > AppArmor: > > https://www.redhat.com/archives/linux-audit/2014-May/msg00119.html > > > John Johansen tells me that AppArmor previously used the 1500-1599 range > before AppArmor was upstreamed. > > There's a conflicting comment in the kernel stating that 1500-1599 is to > by used by kernel LSPP events. As far as I can tell, there were never > any kernel LSPP events that used the range. Steve is the one that added > that comment so I think it is a safe range for AppArmor to use: > > https://git.kernel.org/linus/90d526c074ae5db484388da56c399acf892b6c17 > > Considering audit-userspace's stance, does the LSM community agree that > common_lsm_audit() should be modified to accept an audit record type > parameter to pass on to audit_log_start()? > > If so, does everyone agree that 1500-1599 would be acceptable for > AppArmor to use? Why not change the comment and continue to use the 1400 range, adding events as necessary?