On Wed, 2023-12-27 at 17:39 +0100, Roberto Sassu wrote: > On 12/27/2023 2:22 PM, Mimi Zohar wrote: > > On Thu, 2023-12-14 at 18:08 +0100, Roberto Sassu wrote: > >> From: Roberto Sassu <roberto.sassu@xxxxxxxxxx> > >> > >> Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA > >> own integrity metadata (ima_iint_cache structure, with IMA-specific fields > >> from the integrity_iint_cache structure), and by managing it directly from > >> the 'ima' LSM. > >> > >> Move the remaining IMA-specific flags to security/integrity/ima/ima.h, > >> since they are now unnecessary in the common integrity layer. > >> > >> Replace integrity_iint_cache with ima_iint_cache in various places > >> of the IMA code. > >> > >> Then, reserve space in the security blob for the entire ima_iint_cache > >> structure, so that it is available for all inodes having the security blob > >> allocated (those for which security_inode_alloc() was called). Adjust the > >> IMA code accordingly, call ima_iint_inode() to retrieve the ima_iint_cache > >> structure. Keep the non-NULL checks since there can be inodes without > >> security blob. > > > > Previously the 'iint' memory was only allocated for regular files in > > policy and were tagged S_IMA. This patch totally changes when and how > > memory is being allocated. Does it make sense to allocate memory at > > security_inode_alloc()? Is this change really necessary for making IMA > > a full fledged LSM? > > Good question. I think it wouldn't be necessary, we can reuse the same > approach as in the patch 'integrity: Switch from rbtree to LSM-managed > blob for integrity_iint_cache'. Going forward with the v8 proposed solution would require some real memory usage analysis for different types of policies. To me the "integrity: Switch from rbtree to LSM-managed blob for integrity_iint_cache" makes a lot more sense. Looking back at the original thread, your reasons back then for not directly allocating the integrity_iint_cache are still valid for the ima_iint_cache structure. Mimi > > > >> > >> Don't include the inode pointer as field in the ima_iint_cache structure, > >> since the association with the inode is clear. Since the inode field is > >> missing in ima_iint_cache, pass the extra inode parameter to > >> ima_get_verity_digest(). > >> > >> Finally, register ima_inode_alloc_security/ima_inode_free_security() to > >> initialize/deinitialize the new ima_iint_cache structure (before this task > >> was done by iint_init_always() and iint_free()). Also, duplicate > >> iint_lockdep_annotate() for the ima_iint_cache structure, and name it > >> ima_iint_lockdep_annotate(). > >> > >> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx> >
