This change adds a new LSM hook, inode_init_security_anon(), that will
be used while creating secure anonymous inodes. The hook allows/denies
its creation and assigns a security context to the inode.
The new hook accepts an optional context_inode parameter that callers
can use to provide additional contextual information to security modules
for granting/denying permission to create an anon-inode of the same type.
This context_inode's security_context can also be used to initialize the
newly created anon-inode's security_context.
Signed-off-by: Lokesh Gidra <lokeshgidra@xxxxxxxxxx>
Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
include/linux/lsm_hook_defs.h | 2 ++
include/linux/lsm_hooks.h | 9 +++++++++
include/linux/security.h | 10 ++++++++++
security/security.c | 8 ++++++++
4 files changed, 29 insertions(+)
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 32a940117e7a..435a2e22ff95 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -113,6 +113,8 @@ LSM_HOOK(void, LSM_RET_VOID, inode_free_security, struct inode *inode)
LSM_HOOK(int, 0, inode_init_security, struct inode *inode,
struct inode *dir, const struct qstr *qstr, const char **name,
void **value, size_t *len)
+LSM_HOOK(int, 0, inode_init_security_anon, struct inode *inode,
+ const struct qstr *name, const struct inode *context_inode)
LSM_HOOK(int, 0, inode_create, struct inode *dir, struct dentry *dentry,
umode_t mode)
LSM_HOOK(int, 0, inode_link, struct dentry *old_dentry, struct inode *dir,
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index c503f7ab8afb..3af055b7ee1f 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -233,6 +233,15 @@
* Returns 0 if @name and @value have been successfully set,
* -EOPNOTSUPP if no security attribute is needed, or
* -ENOMEM on memory allocation failure.
+ * @inode_init_security_anon:
+ * Set up the incore security field for the new anonymous inode
+ * and return whether the inode creation is permitted by the security
+ * module or not.
+ * @inode contains the inode structure
+ * @name name of the anonymous inode class
+ * @context_inode optional related inode
+ * Returns 0 on success, -EACCES if the security module denies the
+ * creation of this inode, or another -errno upon other errors.
* @inode_create:
* Check permission to create a regular file.
* @dir contains inode structure of the parent of the new file.
diff --git a/include/linux/security.h b/include/linux/security.h
index bc2725491560..7494a93b9ed9 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -323,6 +323,9 @@ void security_inode_free(struct inode *inode);
int security_inode_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr,
initxattrs initxattrs, void *fs_data);
+int security_inode_init_security_anon(struct inode *inode,
+ const struct qstr *name,
+ const struct inode *context_inode);
int security_old_inode_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr, const char **name,
void **value, size_t *len);
@@ -737,6 +740,13 @@ static inline int security_inode_init_security(struct inode *inode,
return 0;
}
+static inline int security_inode_init_security_anon(struct inode *inode,
+ const struct qstr *name,
+ const struct inode *context_inode)
+{
+ return 0;
+}
+
static inline int security_old_inode_init_security(struct inode *inode,
struct inode *dir,
const struct qstr *qstr,
diff --git a/security/security.c b/security/security.c
index a28045dc9e7f..8989ba6af4f6 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1058,6 +1058,14 @@ int security_inode_init_security(struct inode *inode, struct inode *dir,
}
EXPORT_SYMBOL(security_inode_init_security);
+int security_inode_init_security_anon(struct inode *inode,
+ const struct qstr *name,
+ const struct inode *context_inode)
+{
+ return call_int_hook(inode_init_security_anon, 0, inode, name,
+ context_inode);
+}
+
int security_old_inode_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr, const char **name,
void **value, size_t *len)
--
2.29.2.299.gdc1121823c-goog
