On Jan 15, 2024 Roberto Sassu roberto.sassu@huaweicloud.com wrote:
As for IMA, move hardcoded EVM function calls from various places in the kernel to the LSM infrastructure, by introducing a new LSM named 'evm' (last and always enabled like 'ima'). The order in the Makefile ensures that 'evm' hooks are executed after 'ima' ones.
Let's add a comment to the Makefile about this so everyone knows not to mix up the ordering, otherwise this looks good to me.
At some point I think we may want to introduce the concept of numerical priorities to security_add_hooks() to add some additional granularity beyond the LSM_ORDER_XXX priority, but that is something we can do later.
Acked-by: Paul Moore paul@paul-moore.com
Make EVM functions as static (except for evm_inode_init_security(), which is exported), and register them as hook implementations in init_evm_lsm(). Also move the inline functions evm_inode_remove_acl(), evm_inode_post_remove_acl(), and evm_inode_post_set_acl() from the public evm.h header to evm_main.c.
Unlike before (see commit to move IMA to the LSM infrastructure), evm_inode_post_setattr(), evm_inode_post_set_acl(), evm_inode_post_remove_acl(), and evm_inode_post_removexattr() are not executed for private inodes.
Finally, add the LSM_ID_EVM case in lsm_list_modules_test.c
Signed-off-by: Roberto Sassu roberto.sassu@huawei.com Reviewed-by: Casey Schaufler casey@schaufler-ca.com
fs/attr.c | 2 - fs/posix_acl.c | 3 - fs/xattr.c | 2 - include/linux/evm.h | 113 ----------------- include/uapi/linux/lsm.h | 1 + security/integrity/evm/evm_main.c | 118 +++++++++++++++--- security/security.c | 43 ++----- .../selftests/lsm/lsm_list_modules_test.c | 3 + 8 files changed, 116 insertions(+), 169 deletions(-)
-- paul-moore.com