evm: evm_inode_post_removexattr

When an EVM protected extended attribute is removed, update 'security.evm'.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>

fs/xattr.c

@@ -14,6 +14,7 @@
 #include <linux/mount.h>
 #include <linux/namei.h>
 #include <linux/security.h>
+#include <linux/evm.h>
 #include <linux/syscalls.h>
 #include <linux/module.h>
 #include <linux/fsnotify.h>
@@ -301,8 +302,10 @@ vfs_removexattr(struct dentry *dentry, const char *name)
 	error = inode->i_op->removexattr(dentry, name);
 	mutex_unlock(&inode->i_mutex);
 
-	if (!error)
+	if (!error) {
 		fsnotify_xattr(dentry);
+		evm_inode_post_removexattr(dentry, name);
+	}
 	return error;
 }
 EXPORT_SYMBOL_GPL(vfs_removexattr);

include/linux/evm.h

@@ -22,6 +22,8 @@ extern void evm_inode_post_setxattr(struct dentry *dentry,
 				    const void *xattr_value,
 				    size_t xattr_value_len);
 extern int evm_inode_removexattr(struct dentry *dentry, const char *xattr_name);
+extern void evm_inode_post_removexattr(struct dentry *dentry,
+				       const char *xattr_name);
 #else
 #ifdef CONFIG_INTEGRITY
 static inline enum integrity_status evm_verifyxattr(struct dentry *dentry,
@@ -52,5 +54,12 @@ static inline int evm_inode_removexattr(struct dentry *dentry,
 {
 	return 0;
 }
+
+static inline void evm_inode_post_removexattr(struct dentry *dentry,
+					      const char *xattr_name)
+{
+	return;
+}
+
 #endif /* CONFIG_EVM_H */
 #endif /* LINUX_EVM_H */