vfs: increment iversion when a file is truncated

When a file is truncated with truncate()/ftruncate() and then closed, iversion is not updated. This patch uses ATTR_SIZE flag as an indication to increment iversion. Mimi said: On fput(), i_version is used to detect and flag files that have changed and need to be re-measured in the IMA measurement policy. When a file is truncated with truncate()/ftruncate() and then closed, i_version is not updated. As a result, although the file has changed, it will not be re-measured and added to the IMA measurement list on subsequent access. Signed-off-by: Dmitry Kasatkin <[email protected]> Acked-by: Mimi Zohar <[email protected]> Cc: Al Viro <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Al Viro <[email protected]>
josf · May 31, 2012 · 799243a · 799243a
1 parent a0a9b04
commit 799243a
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/fs/attr.c b/fs/attr.c
@@ -176,6 +176,11 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
 			return -EPERM;
 	}
 
+	if ((ia_valid & ATTR_SIZE) && IS_I_VERSION(inode)) {
+		if (attr->ia_size != inode->i_size)
+			inode_inc_iversion(inode);
+	}
+
 	if ((ia_valid & ATTR_MODE)) {
 		umode_t amode = attr->ia_mode;
 		/* Flag setting protected by i_mutex */