security: define kernel_read_file hook

The kernel_read_file security hook is called prior to reading the file
into memory.

Changelog v4+:
- export security_kernel_read_file()

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/ima.h b/include/linux/ima.h
index 7aea4863c244..6adcaea8101c 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -19,6 +19,7 @@ extern int ima_file_check(struct file *file, int mask, int opened);
 extern void ima_file_free(struct file *file);
 extern int ima_file_mmap(struct file *file, unsigned long prot);
 extern int ima_module_check(struct file *file);
+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);
 
@@ -48,6 +49,11 @@ static inline int ima_module_check(struct file *file)
 	return 0;
 }
 
+static inline int ima_read_file(struct file *file, enum kernel_read_file_id id)
+{
+	return 0;
+}
+
 static inline int ima_post_read_file(struct file *file, void *buf, loff_t size,
 				     enum kernel_read_file_id id)
 {