Re: [PATCH 16/28] security: Introduce file_post_open hook

From: Stefan Berger
Date: Mon Mar 06 2023 - 14:25:30 EST




On 3/3/23 13:18, Roberto Sassu wrote:
From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>

In preparation to move IMA and EVM to the LSM infrastructure, introduce the
file_post_open hook. Also, export security_file_post_open() for NFS.

Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>

+/**
+ * security_file_post_open() - Recheck access to a file after it has been opened
+ * @file: the file
+ * @mask: access mask
+ *
+ * Recheck access with mask after the file has been opened. The hook is useful
+ * for LSMs that require the file content to be available in order to make
+ * decisions.
+ *
+ * Return: Returns 0 if permission is granted.
+ */
+int security_file_post_open(struct file *file, int mask)
+{

Files with private inodes don't seem to checked for in any existing functions, either, so no check. Good..

Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>

+ return call_int_hook(file_post_open, 0, file, mask);
+}
+EXPORT_SYMBOL_GPL(security_file_post_open);
+
/**
* security_file_truncate() - Check if truncating a file is allowed
* @file: file