git.ipfire.org Git - thirdparty/openembedded/openembedded-core-contrib.git/blob

   1 From 2351c83a77a478b49cba6beb2ad386835e264744 Mon Sep 17 00:00:00 2001
   2 From: Alan Coopersmith <alan.coopersmith@oracle.com>
   3 Date: Fri, 6 Mar 2015 22:54:58 -0800
   4 Subject: [PATCH] bdfReadCharacters: ensure metrics fit into xCharInfo struct
   5  [CVE-2015-1804]
   6
   7 We use 32-bit ints to read from the bdf file, but then try to stick
   8 into a 16-bit int in the xCharInfo struct, so make sure they won't
   9 overflow that range.
  10
  11 Found by afl-1.24b.
  12
  13 v2: Verify that additions won't overflow 32-bit int range either.
  14 v3: As Julien correctly observes, the previous check for bh & bw not
  15     being < 0 reduces the number of cases we need to check for overflow.
  16
  17 Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
  18 Reviewed-by: Julien Cristau <jcristau@debian.org>
  19
  20 Upstream-Status: backport
  21
  22 Signed-off-by: Li Zhou <li.zhou@windriver.com>
  23 ---
  24  src/bitmap/bdfread.c |   26 ++++++++++++++++++++++++--
  25  1 file changed, 24 insertions(+), 2 deletions(-)
  26
  27 diff --git a/src/bitmap/bdfread.c b/src/bitmap/bdfread.c
  28 index 1b29b81..a0ace8f 100644
  29 --- a/src/bitmap/bdfread.c
  30 +++ b/src/bitmap/bdfread.c
  31 @@ -62,8 +62,16 @@ from The Open Group.
  32
  33  #if HAVE_STDINT_H
  34  #include <stdint.h>
  35 -#elif !defined(INT32_MAX)
  36 -#define INT32_MAX 0x7fffffff
  37 +#else
  38 +# ifndef INT32_MAX
  39 +#  define INT32_MAX 0x7fffffff
  40 +# endif
  41 +# ifndef INT16_MAX
  42 +#  define INT16_MAX 0x7fff
  43 +# endif
  44 +# ifndef INT16_MIN
  45 +#  define INT16_MIN (0 - 0x8000)
  46 +# endif
  47  #endif
  48
  49  #define INDICES 256
  50 @@ -417,6 +425,12 @@ bdfReadCharacters(FontFilePtr file, FontPtr pFont, bdfFileState *pState,
  51             bdfError("DWIDTH y value must be zero\n");
  52             goto BAILOUT;
  53         }
  54 +       /* xCharInfo metrics are stored as INT16 */
  55 +       if ((wx < 0) || (wx > INT16_MAX)) {
  56 +           bdfError("character '%s' has out of range width, %d\n",
  57 +                    charName, wx);
  58 +           goto BAILOUT;
  59 +       }
  60         line = bdfGetLine(file, lineBuf, BDFLINELEN);
  61         if ((!line) || (sscanf((char *) line, "BBX %d %d %d %d", &bw, &bh, &bl, &bb) != 4)) {
  62             bdfError("bad 'BBX'\n");
  63 @@ -427,6 +441,14 @@ bdfReadCharacters(FontFilePtr file, FontPtr pFont, bdfFileState *pState,
  64                      charName, bw, bh);
  65             goto BAILOUT;
  66         }
  67 +       /* xCharInfo metrics are read as int, but stored as INT16 */
  68 +       if ((bl > INT16_MAX) || (bl < INT16_MIN) ||
  69 +           (bb > INT16_MAX) || (bb < INT16_MIN) ||
  70 +           (bw > (INT16_MAX - bl)) || (bh > (INT16_MAX - bb))) {
  71 +           bdfError("character '%s' has out of range metrics, %d %d %d %d\n",
  72 +                    charName, bl, (bl+bw), (bh+bb), -bb);
  73 +           goto BAILOUT;
  74 +       }
  75         line = bdfGetLine(file, lineBuf, BDFLINELEN);
  76         if ((line) && (bdfIsPrefix(line, "ATTRIBUTES"))) {
  77             for (p = line + strlen("ATTRIBUTES ");
  78 --
  79 1.7.9.5
  80