From fd68bb8c56587114fa6eeed39c36c4b347a6a5fc Mon Sep 17 00:00:00 2001
From: David Gibson <david@gibson.dropbear.id.au>
Date: Mon, 27 Feb 2023 23:18:52 +1100
Subject: Make name_node() xstrdup its name argument

The name field of 'struct node' was really always supposed to be a
malloc()ed string, that is owned by the structure.  To avoid an extra
strdup() for strings coming up from the lexer, name_node() expects to take
uch an already malloc()ed string, which means it's not correct to pass it
a static string literal.

That's a pretty non-obvious constraint, so a bunch of incorrect uses have
crept in.  Really, avoiding the extra dup from the lexer isn't a big enough
benefit for this demonstrably dangerous interface.  So change it to do the
xstrdup() itself, removing the burden from callers.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 dtc-parser.y |  2 ++
 dtc.h        |  8 ++++----
 livetree.c   | 17 +++++++++--------
 3 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/dtc-parser.y b/dtc-parser.y
index 9b724e5..4d5eece 100644
--- a/dtc-parser.y
+++ b/dtc-parser.y
@@ -573,10 +573,12 @@ subnode:
 	  DT_PROPNODENAME nodedef
 		{
 			$$ = name_node($2, $1);
+			free($1);
 		}
 	| DT_DEL_NODE DT_PROPNODENAME ';'
 		{
 			$$ = name_node(build_node_delete(&@$), $2);
+			free($2);
 		}
 	| DT_OMIT_NO_REF subnode
 		{
diff --git a/dtc.h b/dtc.h
index 0fca726..4c4aaca 100644
--- a/dtc.h
+++ b/dtc.h
@@ -269,7 +269,7 @@ struct property *reverse_properties(struct property *first);
 struct node *build_node(struct property *proplist, struct node *children,
 			struct srcpos *srcpos);
 struct node *build_node_delete(struct srcpos *srcpos);
-struct node *name_node(struct node *node, char *name);
+struct node *name_node(struct node *node, const char *name);
 struct node *omit_node_if_unused(struct node *node);
 struct node *reference_node(struct node *node);
 struct node *chain_node(struct node *first, struct node *list);
@@ -336,9 +336,9 @@ struct dt_info *build_dt_info(unsigned int dtsflags,
 			      struct reserve_info *reservelist,
 			      struct node *tree, uint32_t boot_cpuid_phys);
 void sort_tree(struct dt_info *dti);
-void generate_label_tree(struct dt_info *dti, char *name, bool allocph);
-void generate_fixups_tree(struct dt_info *dti, char *name);
-void generate_local_fixups_tree(struct dt_info *dti, char *name);
+void generate_label_tree(struct dt_info *dti, const char *name, bool allocph);
+void generate_fixups_tree(struct dt_info *dti, const char *name);
+void generate_local_fixups_tree(struct dt_info *dti, const char *name);
 
 /* Checks */
 
diff --git a/livetree.c b/livetree.c
index f76ad7f..803093f 100644
--- a/livetree.c
+++ b/livetree.c
@@ -116,11 +116,11 @@ struct node *build_node_delete(struct srcpos *srcpos)
 	return new;
 }
 
-struct node *name_node(struct node *node, char *name)
+struct node *name_node(struct node *node, const char *name)
 {
 	assert(node->name == NULL);
 
-	node->name = name;
+	node->name = xstrdup(name);
 
 	return node;
 }
@@ -250,6 +250,7 @@ struct node * add_orphan_node(struct node *dt, struct node *new_node, char *ref)
 	name_node(new_node, "__overlay__");
 	node = build_node(p, new_node, NULL);
 	name_node(node, name);
+	free(name);
 
 	add_child(dt, node);
 	return dt;
@@ -808,18 +809,18 @@ void sort_tree(struct dt_info *dti)
 }
 
 /* utility helper to avoid code duplication */
-static struct node *build_and_name_child_node(struct node *parent, char *name)
+static struct node *build_and_name_child_node(struct node *parent, const char *name)
 {
 	struct node *node;
 
 	node = build_node(NULL, NULL, NULL);
-	name_node(node, xstrdup(name));
+	name_node(node, name);
 	add_child(parent, node);
 
 	return node;
 }
 
-static struct node *build_root_node(struct node *dt, char *name)
+static struct node *build_root_node(struct node *dt, const char *name)
 {
 	struct node *an;
 
@@ -1040,7 +1041,7 @@ static void generate_local_fixups_tree_internal(struct dt_info *dti,
 		generate_local_fixups_tree_internal(dti, lfn, c);
 }
 
-void generate_label_tree(struct dt_info *dti, char *name, bool allocph)
+void generate_label_tree(struct dt_info *dti, const char *name, bool allocph)
 {
 	if (!any_label_tree(dti, dti->dt))
 		return;
@@ -1048,7 +1049,7 @@ void generate_label_tree(struct dt_info *dti, char *name, bool allocph)
 				     dti->dt, allocph);
 }
 
-void generate_fixups_tree(struct dt_info *dti, char *name)
+void generate_fixups_tree(struct dt_info *dti, const char *name)
 {
 	if (!any_fixup_tree(dti, dti->dt))
 		return;
@@ -1056,7 +1057,7 @@ void generate_fixups_tree(struct dt_info *dti, char *name)
 				      dti->dt);
 }
 
-void generate_local_fixups_tree(struct dt_info *dti, char *name)
+void generate_local_fixups_tree(struct dt_info *dti, const char *name)
 {
 	if (!any_local_fixup_tree(dti, dti->dt))
 		return;
-- 
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