From bb3d555d99f4015be2a517e3267c0cf6dc0021f9 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Fri, 2 Jun 2017 15:20:58 -0400
Subject: [PATCH 12/22] Simplify smbios_table_free(), token_table_free(), and
 cmos_obj_free()

Covscan noticed:
Error: BAD_FREE (CWE-763): [#def46]
libsmbios-2.3.3/src/libsmbios_c/smbios/smbios_obj.c:80: address_assign: Assigning: "toReturn" = "&singleton".
libsmbios-2.3.3/src/libsmbios_c/smbios/smbios_obj.c:87: incorrect_free: "init_smbios_struct" frees incorrect pointer "toReturn".
libsmbios-2.3.3/src/libsmbios_c/smbios/smbios_obj.c:370:5: freed_arg: "smbios_table_free" frees parameter "m".
libsmbios-2.3.3/src/libsmbios_c/smbios/smbios_obj.c:111:9: freed_arg: "_smbios_table_free" frees parameter "m".
libsmbios-2.3.3/src/libsmbios_c/smbios/smbios_obj.c:330:5: freed_arg: "free" frees parameter "this".

Covscan noticed:
Error: BAD_FREE (CWE-763): [#def46]
libsmbios-2.3.3/src/libsmbios_c/token/token_obj.c:82: address_assign: Assigning: "toReturn" = "&singleton".
libsmbios-2.3.3/src/libsmbios_c/token/token_obj.c:95: incorrect_free: "token_table_free" frees incorrect pointer "toReturn".
libsmbios-2.3.3/src/libsmbios_c/token/token_obj.c:109:9: freed_arg: "_token_table_free" frees parameter "m".
libsmbios-2.3.3/src/libsmbios_c/token/token_obj.c:249:5: freed_arg: "free" frees parameter "this".

Error: BAD_FREE (CWE-763): [#def1]
libsmbios-2.3.3/src/libsmbios_c/cmos/cmos_obj.c:74: address_assign: Assigning: "toReturn" = "&singleton".
libsmbios-2.3.3/src/libsmbios_c/cmos/cmos_obj.c:95: incorrect_free: "free" frees incorrect pointer "toReturn".

I don't think there's any way to actually hit that path, but there's
also no reason the code needs to have the extra level of indirection for
_smbios_table_free(), _token_table_free(), or _cmos_obj_free(), so just
simplify those out of existence.

Signed-off-by: Peter Jones <pjones@redhat.com>
---
 src/libsmbios_c/cmos/cmos_obj.c     | 25 +++++++++----------------
 src/libsmbios_c/smbios/smbios_obj.c | 37 +++++++++++++++----------------------
 src/libsmbios_c/token/token_obj.c   | 24 ++++++++++--------------
 3 files changed, 34 insertions(+), 52 deletions(-)

diff --git a/src/libsmbios_c/cmos/cmos_obj.c b/src/libsmbios_c/cmos/cmos_obj.c
index 0b6c62544b2..ef145f60d2f 100644
--- a/src/libsmbios_c/cmos/cmos_obj.c
+++ b/src/libsmbios_c/cmos/cmos_obj.c
@@ -155,16 +155,19 @@ out:
     return retval;
 }
 
-void __hidden _cmos_obj_cleanup(struct cmos_access_obj *m)
+void cmos_obj_free(struct cmos_access_obj *m)
 {
+    struct callback *ptr = 0;
+    struct callback *next = 0;
+
+    if (!m)
+        return;
+
     if(m->cleanup)
         m->cleanup(m);
-}
 
-void __hidden _cmos_obj_free(struct cmos_access_obj *m)
-{
-    struct callback *ptr = 0;
-    struct callback *next = 0;
+    if (m == &singleton)
+        return;
 
     ptr = m->cb_list_head;
     // free callback list
@@ -193,16 +196,6 @@ void __hidden _cmos_obj_free(struct cmos_access_obj *m)
     free(m);
 }
 
-void cmos_obj_free(struct cmos_access_obj *m)
-{
-    if (!m) goto out;
-    _cmos_obj_cleanup(m);
-    if (m != &singleton)
-        _cmos_obj_free(m);
-out:
-    return;
-}
-
 void cmos_obj_register_write_callback(struct cmos_access_obj *m, cmos_write_callback cb_fn, void *userdata, void (*destructor)(void *))
 {
     clear_err(m);
diff --git a/src/libsmbios_c/smbios/smbios_obj.c b/src/libsmbios_c/smbios/smbios_obj.c
index 2382d9fcd16..0a029a2734e 100644
--- a/src/libsmbios_c/smbios/smbios_obj.c
+++ b/src/libsmbios_c/smbios/smbios_obj.c
@@ -104,14 +104,23 @@ out:
     return toReturn;
 }
 
-void smbios_table_free(struct smbios_table *m)
+void smbios_table_free(struct smbios_table *this)
 {
-    if (!m) goto out;
-    if (m != &singleton)
-        _smbios_table_free(m);
+    if (!this || this == &singleton)
+        return;
 
-out:
-    return;
+    memset(&this->tep, 0, sizeof(this->tep));
+
+    free(this->errstring);
+    this->errstring = 0;
+
+    free(this->table);
+    this->table = 0;
+
+    this->initialized=0;
+
+    memset(this, 0, sizeof(*this)); // big hammer
+    free(this);
 }
 
 const char *smbios_table_strerror(const struct smbios_table *m)
@@ -314,22 +323,6 @@ void smbios_table_walk(struct smbios_table *table, void (*fn)(const struct smbio
  *
  **************************************************/
 
-void __hidden _smbios_table_free(struct smbios_table *this)
-{
-    memset(&this->tep, 0, sizeof(this->tep));
-
-    free(this->errstring);
-    this->errstring = 0;
-
-    free(this->table);
-    this->table = 0;
-
-    this->initialized=0;
-
-    memset(this, 0, sizeof(*this)); // big hammer
-    free(this);
-}
-
 int __hidden init_smbios_struct(struct smbios_table *m)
 {
     char *errbuf;
diff --git a/src/libsmbios_c/token/token_obj.c b/src/libsmbios_c/token/token_obj.c
index 8f6aaac05cd..b5948ae5a86 100644
--- a/src/libsmbios_c/token/token_obj.c
+++ b/src/libsmbios_c/token/token_obj.c
@@ -38,7 +38,7 @@
 
 // forward declarations
 static int init_token_table(struct token_table *);
-static void _token_table_free(struct token_table *);
+static void _token_table_free_tokens(struct token_table *this);
 
 // static vars
 static struct token_table singleton; // auto-init to 0
@@ -101,14 +101,20 @@ out:
     return toReturn;
 }
 
-
 void token_table_free(struct token_table *m)
 {
     fnprintf("\n");
-    if (m && m != &singleton)
-        _token_table_free(m);
 
     // can do special cleanup for singleton, but none necessary atm
+    if (!m || m == &singleton)
+        return;
+
+    _token_table_free_tokens(m);
+
+    free(m->errstring);
+    m->errstring = 0;
+
+    free(m);
 }
 
 const char * token_table_strerror(const struct token_table *table)
@@ -239,16 +245,6 @@ static void _token_table_free_tokens(struct token_table *this)
     this->list_head = 0;
 }
 
-static void _token_table_free(struct token_table *this)
-{
-    _token_table_free_tokens(this);
-
-    free(this->errstring);
-    this->errstring = 0;
-
-    free(this);
-}
-
 void __hidden add_token(struct token_table *t, struct token_obj *o)
 {
     struct token_obj *ptr = t->list_head;
-- 
2.14.3