The hook applies the same logic as selinux_determine_inode_label(), with
the exception of the super_block handling, which will be enforced on the
actual inodes later by other hooks.
Signed-off-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
---
security/selinux/hooks.c | 62 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 7dea5b1a89a3..2b72aa50392d 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3353,6 +3353,66 @@ static int selinux_inode_copy_up_xattr(const char *name)
return -EOPNOTSUPP;
}
+/* kernfs node operations */
+
+int selinux_kernfs_init_security(const struct qstr *qstr,
+ const struct iattr *dir_iattr,
+ struct simple_xattrs *dir_secattr,
+ const struct iattr *iattr,
+ struct simple_xattrs *secattr)
+{
+ const struct task_security_struct *tsec = current_security();
+ u32 parent_sid, newsid, clen;
+ int rc;
+ char *context;
+
+ rc = simple_xattr_get(dir_secattr, XATTR_SELINUX_SUFFIX, NULL, 0);
+ if (rc == -ENODATA)
+ return 0;
+ else if (rc < 0)
+ return rc;
+
+ clen = (u32)rc;
+ context = kmalloc(clen, GFP_KERNEL);
+ if (!context)
+ return -ENOMEM;
+
+ rc = simple_xattr_get(dir_secattr, XATTR_SELINUX_SUFFIX, context, clen);
+ if (rc < 0) {
+ kfree(context);
+ return rc;
+ }
+
+ rc = security_context_to_sid(&selinux_state, context, clen, &parent_sid,
+ GFP_KERNEL);
+ kfree(context);
+ if (rc)
+ return rc;
+
+ if (tsec->create_sid) {
+ newsid = tsec->create_sid;
+ } else {
+ u16 secclass = inode_mode_to_security_class(iattr->ia_mode);
+
+ rc = security_transition_sid(&selinux_state, tsec->sid,
+ parent_sid, secclass, qstr,
+ &newsid);
+ if (rc)
+ return rc;
+ }
+
+ rc = security_sid_to_context_force(&selinux_state, newsid,
+ &context, &clen);
+ if (rc)
+ return rc;
+
+ rc = simple_xattr_set(secattr, XATTR_SELINUX_SUFFIX, context, clen,
+ XATTR_CREATE);
+ kfree(context);
+ return rc;
+}
+
+
/* file security operations */
static int selinux_revalidate_file_permission(struct file *file, int mask)
@@ -6799,6 +6859,8 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
+ LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security),
+
LSM_HOOK_INIT(file_permission, selinux_file_permission),
LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
LSM_HOOK_INIT(file_free_security, selinux_file_free_security),
--
2.20.1
