On Thu, 2023-12-14 at 18:08 +0100, Roberto Sassu wrote: > From: Roberto Sassu <roberto.sassu@xxxxxxxxxx> > > Move hardcoded IMA function calls (not appraisal-specific functions) from > various places in the kernel to the LSM infrastructure, by introducing a > new LSM named 'ima' (at the end of the LSM list and always enabled like > 'integrity'). > > Having IMA before EVM in the Makefile is sufficient to preserve the > relative order of the new 'ima' LSM in respect to the upcoming 'evm' LSM, > and thus the order of IMA and EVM function calls as when they were > hardcoded. > > Make moved functions as static (except ima_post_key_create_or_update(), > which is not in ima_main.c), and register them as implementation of the > respective hooks in the new function init_ima_lsm(). > > A slight difference is that IMA and EVM functions registered for the > inode_post_setattr, inode_post_removexattr, path_post_mknod, > inode_post_create_tmpfile, inode_post_set_acl and inode_post_remove_acl > won't be executed for private inodes. Since those inodes are supposed to be > fs-internal, they should not be of interest of IMA or EVM. The S_PRIVATE > flag is used for anonymous inodes, hugetlbfs, reiserfs xattrs, XFS scrub > and kernel-internal tmpfs files. > > Conditionally register ima_post_path_mknod() if CONFIG_SECURITY_PATH is > enabled, otherwise the path_post_mknod hook won't be available. Up to this point, enabling CONFIG_SECURITY_PATH was not required. By making it conditional on CONFIG_SECURITY_PATH, anyone enabling IMA will also need to enable CONFIG_SECURITY_PATH. Without it, new files will not be tagged as a "new" file. Casey, Paul, how common is it today not to enable CONFIG_SECURITY_PATH? Will enabling it just for IMA be a problem? > > Also, conditionally register ima_post_key_create_or_update() if > CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled. > > Move integrity_kernel_module_request() to IMA and name it > ima_kernel_module_request(), as only appraisal is affected by the crypto > subsystem trying to load kernel modules. Conditionally register > ima_kernel_module_request() if CONFIG_INTEGRITY_ASYMMETRIC_KEYS is > enabled. The previous version was so clean. Moving integrity_kernel_module_request() to IMA should be a separate patch, probably a prereq. Then like the other functions convert it to an LSM hook. Please include a line explaning why the original EVM signature is not affected. > > Finally, add the LSM_ID_IMA case in lsm_list_modules_test.c. > > Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx> > Acked-by: Chuck Lever <chuck.lever@xxxxxxxxxx> -- thanks, Mimi
