On Jan 15, 2024 Roberto Sassu roberto.sassu@huaweicloud.com wrote:
In preparation for moving IMA and EVM to the LSM infrastructure, introduce the inode_post_removexattr hook.
At inode_removexattr hook, EVM verifies the file's existing HMAC value. At inode_post_removexattr, EVM re-calculates the file's HMAC with the passed xattr removed and other file metadata.
Other LSMs could similarly take some action after successful xattr removal.
The new hook cannot return an error and cannot cause the operation to be reverted.
Signed-off-by: Roberto Sassu roberto.sassu@huawei.com Reviewed-by: Stefan Berger stefanb@linux.ibm.com Reviewed-by: Mimi Zohar zohar@linux.ibm.com Reviewed-by: Casey Schaufler casey@schaufler-ca.com
fs/xattr.c | 9 +++++---- include/linux/lsm_hook_defs.h | 2 ++ include/linux/security.h | 5 +++++ security/security.c | 14 ++++++++++++++ 4 files changed, 26 insertions(+), 4 deletions(-)
Acked-by: Paul Moore paul@paul-moore.com
-- paul-moore.com