glibc/glibc-CVE-2013-4332.patch

   1 From 0d6085cb1b4330b835ad08a3ec8f80b30f0cadb4 Mon Sep 17 00:00:00 2001
   2 From: mancha <mancha1@hush.com>
   3 Date: Wed, 11 Sep 2013
   4 Subject: CVE-2013-4332
   5
   6 malloc: Check for integer overflow in pvalloc, valloc, and memalign.
   7
   8 A large bytes parameter to pvalloc, valloc, or memalign could cause
   9 an integer overflow and corrupt allocator internals. Check the
  10 overflow does not occur before continuing with the allocation.
  11
  12 Note: This is a backport to glibc 2.17 of the following three commits:
  13     * https://sourceware.org/git/?p=glibc.git;a=commit;h=1159a193696a
  14     * https://sourceware.org/git/?p=glibc.git;a=commit;h=55e17aadc1ef
  15     * https://sourceware.org/git/?p=glibc.git;a=commit;h=b73ed247781d
  16 ---
  17
  18 malloc.c |   21 +++++++++++++++++++++
  19  1 file changed, 21 insertions(+)
  20
  21 --- a/malloc/malloc.c
  22 +++ b/malloc/malloc.c
  23 @@ -3020,6 +3020,13 @@ __libc_memalign(size_t alignment, size_t
  24    /* Otherwise, ensure that it is at least a minimum chunk size */
  25    if (alignment <  MINSIZE) alignment = MINSIZE;
  26
  27 +  /* Check for overflow.  */
  28 +  if (bytes > SIZE_MAX - alignment - MINSIZE)
  29 +    {
  30 +      __set_errno (ENOMEM);
  31 +      return 0;
  32 +    }
  33 +
  34    arena_get(ar_ptr, bytes + alignment + MINSIZE);
  35    if(!ar_ptr)
  36      return 0;
  37 @@ -3051,6 +3058,13 @@ __libc_valloc(size_t bytes)
  38
  39    size_t pagesz = GLRO(dl_pagesize);
  40
  41 +  /* Check for overflow.  */
  42 +  if (bytes > SIZE_MAX - pagesz - MINSIZE)
  43 +    {
  44 +      __set_errno (ENOMEM);
  45 +      return 0;
  46 +    }
  47 +
  48    __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, size_t,
  49                                         const __malloc_ptr_t)) =
  50      force_reg (__memalign_hook);
  51 @@ -3088,6 +3102,13 @@ __libc_pvalloc(size_t bytes)
  52    size_t page_mask = GLRO(dl_pagesize) - 1;
  53    size_t rounded_bytes = (bytes + page_mask) & ~(page_mask);
  54
  55 +  /* Check for overflow.  */
  56 +  if (bytes > SIZE_MAX - 2*pagesz - MINSIZE)
  57 +    {
  58 +      __set_errno (ENOMEM);
  59 +      return 0;
  60 +    }
  61 +
  62    __malloc_ptr_t (*hook) __MALLOC_PMT ((size_t, size_t,
  63                                         const __malloc_ptr_t)) =
  64      force_reg (__memalign_hook);