From: Michael Brown <mcb30@ipxe.org>
Date: Tue, 3 Mar 2015 00:29:42 +0000 (+0000)
Subject: [settings] Use list_first_entry() when unregistering child settings
X-Git-Tag: v1.20.1~930
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0af3d14a2379fd7775ef09b5f882682496f7cbe6;p=thirdparty%2Fipxe.git

[settings] Use list_first_entry() when unregistering child settings

Unregistering a child settings block can have almost arbitrary
effects, due to the call to apply_settings().  Avoid potentially
dereferencing a stale pointer by using list_first_entry() rather than
list_for_each_entry_safe() to iterate over the list of child settings.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---

diff --git a/src/core/settings.c b/src/core/settings.c
index 5e16b27d0..85d95e6eb 100644
--- a/src/core/settings.c
+++ b/src/core/settings.c
@@ -499,10 +499,10 @@ int register_settings ( struct settings *settings, struct settings *parent,
  */
 void unregister_settings ( struct settings *settings ) {
 	struct settings *child;
-	struct settings *tmp;
 
 	/* Unregister child settings */
-	list_for_each_entry_safe ( child, tmp, &settings->children, siblings ) {
+	while ( ( child = list_first_entry ( &settings->children,
+					     struct settings, siblings ) ) ) {
 		unregister_settings ( child );
 	}