[RFC v2 10/19] ima: Implement hierarchical processing of file accesses
From: Stefan Berger <stefanb@linux.ibm.com>
Date: 2021-12-03 02:32:08
Also in:
linux-security-module, lkml
Subsystem:
extended verification module (evm), integrity measurement architecture (ima), security subsystem, the rest · Maintainers:
Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
Implement hierarchical processing of file accesses in IMA namespaces by walking the list of IMA namespaces towards the init_ima_ns. This way file accesses can be audited in an IMA namespace and also be evaluated against the IMA policies of parent IMA namespaces. Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> --- security/integrity/ima/ima_main.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-)
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index d692c9d53a98..42cbcaf2dc1e 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c@@ -199,10 +199,10 @@ void ima_file_free(struct file *file) ima_check_last_writer(iint, inode, file); } -static int process_measurement(struct ima_namespace *ns, - struct file *file, const struct cred *cred, - u32 secid, char *buf, loff_t size, int mask, - enum ima_hooks func) +static int _process_measurement(struct ima_namespace *ns, + struct file *file, const struct cred *cred, + u32 secid, char *buf, loff_t size, int mask, + enum ima_hooks func) { struct inode *inode = file_inode(file); struct integrity_iint_cache *iint = NULL;
@@ -404,6 +404,27 @@ static int process_measurement(struct ima_namespace *ns, return 0; } +static int process_measurement(struct ima_namespace *ns, + struct file *file, const struct cred *cred, + u32 secid, char *buf, loff_t size, int mask, + enum ima_hooks func) +{ + int ret = 0; + struct user_namespace *user_ns; + + do { + ret = _process_measurement(ns, file, cred, secid, buf, size, mask, func); + if (ret) + break; + user_ns = ns->user_ns->parent; + if (!user_ns) + break; + ns = user_ns->ima_ns; + } while (1); + + return ret; +} + /** * ima_file_mmap - based on policy, collect/store measurement. * @file: pointer to the file to be measured (May be NULL)
--
2.31.1