From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Peter Jones <pjones@redhat.com>

Date: Mon, 15 Jun 2020 12:15:29 -0400

Subject: [PATCH] calloc: Make sure we always have an overflow-checking

 calloc() available

This tries to make sure that everywhere in this source tree, we always have

an appropriate version of calloc() (i.e. grub_calloc(), xcalloc(), etc.)

available, and that they all safely check for overflow and return NULL when

it would occur.

Signed-off-by: Peter Jones <pjones@redhat.com>

Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

Upstream-commit-id: 79e51ab7a9a

---

 grub-core/kern/emu/misc.c          | 12 ++++++++++++

 grub-core/kern/emu/mm.c            | 10 ++++++++++

 grub-core/kern/mm.c                | 40 ++++++++++++++++++++++++++++++++++++++

 grub-core/lib/libgcrypt_wrap/mem.c | 11 +++++++++--

 grub-core/lib/posix_wrap/stdlib.h  |  8 +++++++-

 include/grub/emu/misc.h            |  1 +

 include/grub/mm.h                  |  6 ++++++

 7 files changed, 85 insertions(+), 3 deletions(-)

diff --git a/grub-core/kern/emu/misc.c b/grub-core/kern/emu/misc.c

index 7a8d9e62300..f08a1bb8415 100644

--- a/grub-core/kern/emu/misc.c

+++ b/grub-core/kern/emu/misc.c

@@ -86,6 +86,18 @@ grub_util_error (const char *fmt, ...)

   grub_exit (1);

 }

+void *

+xcalloc (grub_size_t nmemb, grub_size_t size)

+{

+  void *p;

+

+  p = calloc (nmemb, size);

+  if (!p)

+    grub_util_error ("%s", _("out of memory"));

+

+  return p;

+}

+

 void *

 xmalloc (grub_size_t size)

 {

diff --git a/grub-core/kern/emu/mm.c b/grub-core/kern/emu/mm.c

index f262e95e388..145b01d3719 100644

--- a/grub-core/kern/emu/mm.c

+++ b/grub-core/kern/emu/mm.c

@@ -25,6 +25,16 @@

 #include <string.h>

 #include <grub/i18n.h>

+void *

+grub_calloc (grub_size_t nmemb, grub_size_t size)

+{

+  void *ret;

+  ret = calloc (nmemb, size);

+  if (!ret)

+    grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));

+  return ret;

+}

+

 void *

 grub_malloc (grub_size_t size)

 {

diff --git a/grub-core/kern/mm.c b/grub-core/kern/mm.c

index 002cbfa4f3d..80d0720d005 100644

--- a/grub-core/kern/mm.c

+++ b/grub-core/kern/mm.c

@@ -67,8 +67,10 @@

 #include <grub/dl.h>

 #include <grub/i18n.h>

 #include <grub/mm_private.h>

+#include <grub/safemath.h>

 #ifdef MM_DEBUG

+# undef grub_calloc

 # undef grub_malloc

 # undef grub_zalloc

 # undef grub_realloc

@@ -375,6 +377,30 @@ grub_memalign (grub_size_t align, grub_size_t size)

   return 0;

 }

+/*

+ * Allocate NMEMB instances of SIZE bytes and return the pointer, or error on

+ * integer overflow.

+ */

+void *

+grub_calloc (grub_size_t nmemb, grub_size_t size)

+{

+  void *ret;

+  grub_size_t sz = 0;

+

+  if (grub_mul (nmemb, size, &sz))

+    {

+      grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected"));

+      return NULL;

+    }

+

+  ret = grub_memalign (0, sz);

+  if (!ret)

+    return NULL;

+

+  grub_memset (ret, 0, sz);

+  return ret;

+}

+

 /* Allocate SIZE bytes and return the pointer.  */

 void *

 grub_malloc (grub_size_t size)

@@ -561,6 +587,20 @@ grub_mm_dump (unsigned lineno)

   grub_printf ("\n");

 }

+void *

+grub_debug_calloc (const char *file, int line, grub_size_t nmemb, grub_size_t size)

+{

+  void *ptr;

+

+  if (grub_mm_debug)

+    grub_printf ("%s:%d: calloc (0x%" PRIxGRUB_SIZE ", 0x%" PRIxGRUB_SIZE ") = ",

+		 file, line, size);

+  ptr = grub_calloc (nmemb, size);

+  if (grub_mm_debug)

+    grub_printf ("%p\n", ptr);

+  return ptr;

+}

+

 void *

 grub_debug_malloc (const char *file, int line, grub_size_t size)

 {

diff --git a/grub-core/lib/libgcrypt_wrap/mem.c b/grub-core/lib/libgcrypt_wrap/mem.c

index beeb661a3c8..74c6eafe525 100644

--- a/grub-core/lib/libgcrypt_wrap/mem.c

+++ b/grub-core/lib/libgcrypt_wrap/mem.c

@@ -4,6 +4,7 @@

 #include <grub/crypto.h>

 #include <grub/dl.h>

 #include <grub/env.h>

+#include <grub/safemath.h>

 GRUB_MOD_LICENSE ("GPLv3+");

@@ -36,7 +37,10 @@ void *

 gcry_xcalloc (size_t n, size_t m)

 {

   void *ret;

-  ret = grub_zalloc (n * m);

+  size_t sz;

+  if (grub_mul (n, m, &sz))

+    grub_fatal ("gcry_xcalloc would overflow");

+  ret = grub_zalloc (sz);

   if (!ret)

     grub_fatal ("gcry_xcalloc failed");

   return ret;

@@ -56,7 +60,10 @@ void *

 gcry_xcalloc_secure (size_t n, size_t m)

 {

   void *ret;

-  ret = grub_zalloc (n * m);

+  size_t sz;

+  if (grub_mul (n, m, &sz))

+    grub_fatal ("gcry_xcalloc would overflow");

+  ret = grub_zalloc (sz);

   if (!ret)

     grub_fatal ("gcry_xcalloc failed");

   return ret;

diff --git a/grub-core/lib/posix_wrap/stdlib.h b/grub-core/lib/posix_wrap/stdlib.h

index 3b46f47ff50..7a8d385e973 100644

--- a/grub-core/lib/posix_wrap/stdlib.h

+++ b/grub-core/lib/posix_wrap/stdlib.h

@@ -21,6 +21,7 @@

 #include <grub/mm.h>

 #include <grub/misc.h>

+#include <grub/safemath.h>

 static inline void 

 free (void *ptr)

@@ -37,7 +38,12 @@ malloc (grub_size_t size)

 static inline void *

 calloc (grub_size_t size, grub_size_t nelem)

 {

-  return grub_zalloc (size * nelem);

+  grub_size_t sz;

+

+  if (grub_mul (size, nelem, &sz))

+    return NULL;

+

+  return grub_zalloc (sz);

 }

 static inline void *

diff --git a/include/grub/emu/misc.h b/include/grub/emu/misc.h

index 5ef4f79e689..01056954b96 100644

--- a/include/grub/emu/misc.h

+++ b/include/grub/emu/misc.h

@@ -47,6 +47,7 @@ grub_util_device_is_mapped (const char *dev);

 #define GRUB_HOST_PRIuLONG_LONG "llu"

 #define GRUB_HOST_PRIxLONG_LONG "llx"

+void * EXPORT_FUNC(xcalloc) (grub_size_t nmemb, grub_size_t size) WARN_UNUSED_RESULT;

 void * EXPORT_FUNC(xmalloc) (grub_size_t size) WARN_UNUSED_RESULT;

 void * EXPORT_FUNC(xrealloc) (void *ptr, grub_size_t size) WARN_UNUSED_RESULT;

 char * EXPORT_FUNC(xstrdup) (const char *str) WARN_UNUSED_RESULT;

diff --git a/include/grub/mm.h b/include/grub/mm.h

index 28e2e53eb32..9c38dd3ca5d 100644

--- a/include/grub/mm.h

+++ b/include/grub/mm.h

@@ -29,6 +29,7 @@

 #endif

 void grub_mm_init_region (void *addr, grub_size_t size);

+void *EXPORT_FUNC(grub_calloc) (grub_size_t nmemb, grub_size_t size);

 void *EXPORT_FUNC(grub_malloc) (grub_size_t size);

 void *EXPORT_FUNC(grub_zalloc) (grub_size_t size);

 void EXPORT_FUNC(grub_free) (void *ptr);

@@ -48,6 +49,9 @@ extern int EXPORT_VAR(grub_mm_debug);

 void grub_mm_dump_free (void);

 void grub_mm_dump (unsigned lineno);

+#define grub_calloc(nmemb, size)	\

+  grub_debug_calloc (GRUB_FILE, __LINE__, nmemb, size)

+

 #define grub_malloc(size)	\

   grub_debug_malloc (GRUB_FILE, __LINE__, size)

@@ -63,6 +67,8 @@ void grub_mm_dump (unsigned lineno);

 #define grub_free(ptr)	\

   grub_debug_free (GRUB_FILE, __LINE__, ptr)

+void *EXPORT_FUNC(grub_debug_calloc) (const char *file, int line,

+				      grub_size_t nmemb, grub_size_t size);

 void *EXPORT_FUNC(grub_debug_malloc) (const char *file, int line,

 				      grub_size_t size);

 void *EXPORT_FUNC(grub_debug_zalloc) (const char *file, int line,