@@ -3620,6 +3620,8 @@ retry:
switch (mode & S_IFMT) {
case 0: case S_IFREG:
error = vfs_create(path.dentry->d_inode,dentry,mode,true);
+ if (!error)
+ ima_post_path_mknod(dentry);
break;
case S_IFCHR: case S_IFBLK:
error = vfs_mknod(path.dentry->d_inode,dentry,mode,
@@ -21,6 +21,7 @@ extern int ima_file_mmap(struct file *file, unsigned long prot);
extern int ima_read_file(struct file *file, enum kernel_read_file_id id);
extern int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id id);
+extern void ima_post_path_mknod(struct dentry *dentry);
#else
static inline int ima_bprm_check(struct linux_binprm *bprm)
@@ -54,6 +55,11 @@ static inline int ima_post_read_file(struct file *file, void *buf, loff_t size,
return 0;
}
+static inline void ima_post_path_mknod(struct dentry *dentry)
+{
+ return;
+}
+
#endif /* CONFIG_IMA */
#ifdef CONFIG_IMA_APPRAISE
@@ -275,6 +275,11 @@ out:
xattr_value->type != EVM_IMA_XATTR_DIGSIG)) {
if (!ima_fix_xattr(dentry, iint))
status = INTEGRITY_PASS;
+ } else if ((inode->i_size == 0) &&
+ (iint->flags & IMA_NEW_FILE) &&
+ (xattr_value &&
+ xattr_value->type == EVM_IMA_XATTR_DIGSIG)) {
+ status = INTEGRITY_PASS;
}
integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename,
op, cause, rc, 0);
@@ -246,7 +246,8 @@ static int process_measurement(struct file *file, char *buf, loff_t size,
ima_audit_measurement(iint, pathname);
out_digsig:
- if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG))
+ if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG) &&
+ !(iint->flags & IMA_NEW_FILE))
rc = -EACCES;
kfree(xattr_value);
out_free:
@@ -316,6 +317,35 @@ int ima_file_check(struct file *file, int mask, int opened)
EXPORT_SYMBOL_GPL(ima_file_check);
/**
+ * ima_post_path_mknod - mark as a new inode
+ * @dentry: newly created dentry
+ *
+ * Mark files created via the mknodat syscall as new, so that the
+ * file data can be written later.
+ */
+void ima_post_path_mknod(struct dentry *dentry)
+{
+ struct integrity_iint_cache *iint;
+ struct inode *inode;
+ int must_appraise;
+
+ if (!dentry || !dentry->d_inode)
+ return;
+
+ inode = dentry->d_inode;
+ if (inode->i_size != 0)
+ return;
+
+ must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);
+ if (!must_appraise)
+ return;
+
+ iint = integrity_inode_get(inode);
+ if (iint)
+ iint->flags |= IMA_NEW_FILE;
+}
+
+/**
* ima_read_file - pre-measure/appraise hook decision based on policy
* @file: pointer to the file to be measured/appraised/audit
* @read_id: caller identifier