Don't leak compartment name pointers after dlclose()

libexec/rtld-elf/map_object.c

@@ -550,12 +550,8 @@ obj_free(Obj_Entry *obj)
 	free(obj->path);
 #ifdef __CHERI_PURE_CAPABILITY__
 #ifdef CHERI_LIB_C18N
-    if (obj->comparts) {
-	for (unsigned long i = 0; i < obj->ncomparts; i++) {
-	    free(obj->comparts[i].compart_name);
-	}
+    if (obj->comparts)
 	free(obj->comparts);
-    }
 #endif
     if (obj->pcc_caps)
 	free(obj->pcc_caps);

libexec/rtld-elf/rtld.c

@@ -6324,6 +6324,7 @@ c18n_setup_compartments(Obj_Entry *obj, const char *name, int flags)
 {
 	Compart_Entry *compart;
 	const Elf_Phdr *ph;
+	char *compart_name;
 	size_t len;
 
 	assert(obj->default_compart_id == 0);
@@ -6354,11 +6355,12 @@ c18n_setup_compartments(Obj_Entry *obj, const char *name, int flags)
 			compart->end = compart->start + ph->p_memsz;
 
 			len = strlen(name) + 1 + strlen(compart->name) + 1;
-			compart->compart_name = malloc(len);
-			rtld_snprintf(compart->compart_name, len, "%s:%s",
-			    name, compart->name);
+			compart_name = malloc(len);
+			rtld_snprintf(compart_name, len, "%s:%s", name,
+			    compart->name);
 			compart->compart_id =
-			    compart_id_allocate(compart->compart_name, flags);
+			    compart_id_allocate(compart_name, flags);
+			free(compart_name);
 			compart++;
 			break;
 		}

libexec/rtld-elf/rtld.h

@@ -205,7 +205,6 @@ typedef struct Struct_Compart_Entry {
     const char *name;
     Elf_Addr start;
     Elf_Addr end;
-    char *compart_name;
     uint16_t compart_id;
 } Compart_Entry;
 #endif

libexec/rtld-elf/rtld_c18n.c

@@ -190,6 +190,15 @@
 	INC_NUM_BYTES(-old);
 }
 
+static char *
+c18n_strdup(const char *s)
+{
+	char *buf = strdup(s);
+
+	INC_NUM_BYTES(cheri_getlen(buf));
+	return (buf);
+}
+
 /*
  * Policies
  */
@@ -320,10 +329,13 @@
 {
 	compart_id_t i;
 	struct compart *com;
+	char *c_name;
 
 	rtld_require(comparts.size <= COMPART_ID_MAX,
 	    "c18n: Compartment ID overflow for %s", name);
 
+	c_name = c18n_strdup(name);
+
 	if (comparts.size == comparts.capacity)
 		expand_comparts_data(comparts.capacity * 2);
 
@@ -335,10 +347,10 @@
 	com = &comparts.data[i];
 	*com = (struct compart) {
 		.info = (struct rtld_c18n_compart) {
-			.rcc_name = name,
+			.rcc_name = c_name,
 			.rcc_id = i
 		},
-		.name = name
+		.name = c_name
 	};
 	c18n_info->comparts_size = r_debug.r_comparts_size = comparts.size;
 
@@ -485,10 +497,10 @@
 
 		if (eat(&cur, "compartment ")) {
 			if (eat_token(&cur, '\n', buf, sizeof(buf)))
-				com = add_comparts_data(strdup(buf));
+				com = add_comparts_data(buf);
 			else
 				policy_error(&cur);
 
 			while (eat(&cur, "\t"))
 				if (eat_token(&cur, '\n', buf, sizeof(buf)))
 					string_base_push(&com->libs, buf);