[Libunwind-devel] [PATCH 19/27] Fix memory leaks in unw_create_addr_space() wrong-endian error paths

[Tommi Rantala]

Check the endianness earlier in unw_create_addr_space() on all
architectures to avoid leaking the dynamically allocated address space
struct.

This was already fixed for ARM in commit cf6a99879604 ("Fix memory leak
in ARM unw_create_addr_space()"). Move the endianness check also on ARM
to avoid malloc() & free() in the error case.
---
 src/arm/Gcreate_addr_space.c    |   20 +++++++++-----------
 src/hppa/Gcreate_addr_space.c   |   14 ++++++++------
 src/mips/Gcreate_addr_space.c   |   17 +++++++++--------
 src/ppc/Gcreate_addr_space.c    |   14 ++++++++------
 src/x86/Gcreate_addr_space.c    |   14 ++++++++------
 src/x86_64/Gcreate_addr_space.c |   15 +++++++++------
 6 files changed, 51 insertions(+), 43 deletions(-)

diff --git a/src/arm/Gcreate_addr_space.c b/src/arm/Gcreate_addr_space.c
index 5374649..4d59a20 100644
--- a/src/arm/Gcreate_addr_space.c
+++ b/src/arm/Gcreate_addr_space.c
@@ -32,8 +32,16 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
 #ifdef UNW_LOCAL_ONLY
   return NULL;
 #else
-  unw_addr_space_t as = malloc (sizeof (*as));
+  unw_addr_space_t as;
 
+  /*
+   * ARM supports little-endian and big-endian.
+   */
+  if (byte_order != 0 && byte_order != __LITTLE_ENDIAN
+      && byte_order != __BIG_ENDIAN)
+    return NULL;
+
+  as = malloc (sizeof (*as));
   if (!as)
     return NULL;
 
@@ -41,16 +49,6 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
 
   as->acc = *a;
 
-  /*
-   * ARM supports little-endian and big-endian.
-   */
-  if (byte_order != 0 && byte_order != __LITTLE_ENDIAN
-      && byte_order != __BIG_ENDIAN)
-    {
-      free(as);
-      return NULL;
-    }
-  
   /* Default to little-endian for ARM.  */
   if (byte_order == 0 || byte_order == __LITTLE_ENDIAN)
     as->big_endian = 0;
diff --git a/src/hppa/Gcreate_addr_space.c b/src/hppa/Gcreate_addr_space.c
index 8f4301f..ecc805d 100644
--- a/src/hppa/Gcreate_addr_space.c
+++ b/src/hppa/Gcreate_addr_space.c
@@ -33,8 +33,15 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
 #ifdef UNW_LOCAL_ONLY
   return NULL;
 #else
-  unw_addr_space_t as = malloc (sizeof (*as));
+  unw_addr_space_t as;
 
+  /*
+   * hppa supports only big-endian.
+   */
+  if (byte_order != 0 && byte_order != __BIG_ENDIAN)
+    return NULL;
+
+  as = malloc (sizeof (*as));
   if (!as)
     return NULL;
 
@@ -42,11 +49,6 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
 
   as->acc = *a;
 
-  /*
-   * hppa supports only big-endian.
-   */
-  if (byte_order != 0 && byte_order != __BIG_ENDIAN)
-    return NULL;
   return as;
 #endif
 }
diff --git a/src/mips/Gcreate_addr_space.c b/src/mips/Gcreate_addr_space.c
index af084ef..371841d 100644
--- a/src/mips/Gcreate_addr_space.c
+++ b/src/mips/Gcreate_addr_space.c
@@ -32,14 +32,7 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
 #ifdef UNW_LOCAL_ONLY
   return NULL;
 #else
-  unw_addr_space_t as = malloc (sizeof (*as));
-
-  if (!as)
-    return NULL;
-
-  memset (as, 0, sizeof (*as));
-
-  as->acc = *a;
+  unw_addr_space_t as;
 
   /*
    * MIPS supports only big or little-endian, not weird stuff like
@@ -50,6 +43,14 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
       && byte_order != __BIG_ENDIAN)
     return NULL;
 
+  as = malloc (sizeof (*as));
+  if (!as)
+    return NULL;
+
+  memset (as, 0, sizeof (*as));
+
+  as->acc = *a;
+
   if (byte_order == 0)
     /* use host default: */
     as->big_endian = (__BYTE_ORDER == __BIG_ENDIAN);
diff --git a/src/ppc/Gcreate_addr_space.c b/src/ppc/Gcreate_addr_space.c
index 21ec10f..09bde56 100644
--- a/src/ppc/Gcreate_addr_space.c
+++ b/src/ppc/Gcreate_addr_space.c
@@ -35,8 +35,15 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
 #ifdef UNW_LOCAL_ONLY
   return NULL;
 #else
-  unw_addr_space_t as = malloc (sizeof (*as));
+  unw_addr_space_t as;
 
+  /*
+   * Linux ppc64 supports only big-endian.
+   */
+  if (byte_order != 0 && byte_order != __BIG_ENDIAN)
+    return NULL;
+
+  as = malloc (sizeof (*as));
   if (!as)
     return NULL;
 
@@ -44,11 +51,6 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
 
   as->acc = *a;
 
-  /*
-   * Linux ppc64 supports only big-endian.
-   */
-  if (byte_order != 0 && byte_order != __BIG_ENDIAN)
-    return NULL;
   return as;
 #endif
 }
diff --git a/src/x86/Gcreate_addr_space.c b/src/x86/Gcreate_addr_space.c
index 5dd6367..5b07940 100644
--- a/src/x86/Gcreate_addr_space.c
+++ b/src/x86/Gcreate_addr_space.c
@@ -37,8 +37,15 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
 #ifdef UNW_LOCAL_ONLY
   return NULL;
 #else
-  unw_addr_space_t as = malloc (sizeof (*as));
+  unw_addr_space_t as;
 
+  /*
+   * x86 supports only little-endian.
+   */
+  if (byte_order != 0 && byte_order != __LITTLE_ENDIAN)
+    return NULL;
+
+  as = malloc (sizeof (*as));
   if (!as)
     return NULL;
 
@@ -46,11 +53,6 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
 
   as->acc = *a;
 
-  /*
-   * x86 supports only little-endian.
-   */
-  if (byte_order != 0 && byte_order != __LITTLE_ENDIAN)
-    return NULL;
   return as;
 #endif
 }
diff --git a/src/x86_64/Gcreate_addr_space.c b/src/x86_64/Gcreate_addr_space.c
index 02b93eb..aab126a 100644
--- a/src/x86_64/Gcreate_addr_space.c
+++ b/src/x86_64/Gcreate_addr_space.c
@@ -3,6 +3,7 @@
        Contributed by David Mosberger-Tang <address@hidden>
 
    Modified for x86_64 by Max Asbock <address@hidden>
+   Copyright (C) 2012 Tommi Rantala <address@hidden>
 
 This file is part of libunwind.
 
@@ -39,8 +40,15 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
 #ifdef UNW_LOCAL_ONLY
   return NULL;
 #else
-  unw_addr_space_t as = malloc (sizeof (*as));
+  unw_addr_space_t as;
 
+  /*
+   * x86_64 supports only little-endian.
+   */
+  if (byte_order != 0 && byte_order != __LITTLE_ENDIAN)
+    return NULL;
+
+  as = malloc (sizeof (*as));
   if (!as)
     return NULL;
 
@@ -48,11 +56,6 @@ unw_create_addr_space (unw_accessors_t *a, int byte_order)
 
   as->acc = *a;
 
-  /*
-   * x86_64 supports only little-endian.
-   */
-  if (byte_order != 0 && byte_order != __LITTLE_ENDIAN)
-    return NULL;
   return as;
 #endif
 }
-- 
1.7.9.5