glibc/malloc-overflows.patch

2013-09-11  Will Newton  <will.newton@linaro.org>

	[BZ #15857]
	* malloc/malloc.c (__libc_memalign): Check the value of bytes
	does not overflow.

	[BZ #15856]
	* malloc/malloc.c (__libc_valloc): Check the value of bytes
	does not overflow.

	[BZ #15855]
	* malloc/malloc.c (__libc_pvalloc): Check the value of bytes
	does not overflow.

Index: glibc-2.18/malloc/malloc.c
===================================================================
--- glibc-2.18.orig/malloc/malloc.c
+++ glibc-2.18/malloc/malloc.c
@@ -3015,6 +3015,13 @@ __libc_memalign(size_t alignment, size_t
   /* Otherwise, ensure that it is at least a minimum chunk size */
   if (alignment <  MINSIZE) alignment = MINSIZE;
 
+  /* Check for overflow.  */
+  if (bytes > SIZE_MAX - alignment - MINSIZE)
+    {
+      __set_errno (ENOMEM);
+      return 0;
+    }
+
   arena_get(ar_ptr, bytes + alignment + MINSIZE);
   if(!ar_ptr)
     return 0;
@@ -3046,6 +3053,13 @@ __libc_valloc(size_t bytes)
 
   size_t pagesz = GLRO(dl_pagesize);
 
+  /* Check for overflow.  */
+  if (bytes > SIZE_MAX - pagesz - MINSIZE)
+    {
+      __set_errno (ENOMEM);
+      return 0;
+    }
+
   void *(*hook) (size_t, size_t, const void *) =
     force_reg (__memalign_hook);
   if (__builtin_expect (hook != NULL, 0))
@@ -3082,6 +3096,13 @@ __libc_pvalloc(size_t bytes)
   size_t page_mask = GLRO(dl_pagesize) - 1;
   size_t rounded_bytes = (bytes + page_mask) & ~(page_mask);
 
+  /* Check for overflow.  */
+  if (bytes > SIZE_MAX - 2*pagesz - MINSIZE)
+    {
+      __set_errno (ENOMEM);
+      return 0;
+    }
+
   void *(*hook) (size_t, size_t, const void *) =
     force_reg (__memalign_hook);
   if (__builtin_expect (hook != NULL, 0))