gnu/packages/patches/screen-CVE-2021-26937.patch

   1 https://salsa.debian.org/debian/screen/-/raw/debian/4.8.0-5/debian/patches/99_CVE-2021-26937.patch
   2
   3 Description: [CVE-2021-26937] Fix out of bounds array access
   4 Author: Michael Schröder <mls@suse.de>
   5 Bug-Debian: https://bugs.debian.org/982435
   6 Bug: https://savannah.gnu.org/bugs/?60030
   7 Bug: https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00000.html
   8 Bug-OSS-Security: https://www.openwall.com/lists/oss-security/2021/02/09/3
   9 Origin: https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00010.html
  10
  11 --- a/encoding.c
  12 +++ b/encoding.c
  13 @@ -43,7 +43,7 @@
  14  # ifdef UTF8
  15  static int   recode_char __P((int, int, int));
  16  static int   recode_char_to_encoding __P((int, int));
  17 -static void  comb_tofront __P((int, int));
  18 +static void  comb_tofront __P((int));
  19  #  ifdef DW_CHARS
  20  static int   recode_char_dw __P((int, int *, int, int));
  21  static int   recode_char_dw_to_encoding __P((int, int *, int));
  22 @@ -1263,6 +1263,8 @@
  23      {0x30000, 0x3FFFD},
  24    };
  25
  26 +  if (c >= 0xdf00 && c <= 0xdfff)
  27 +    return 1;          /* dw combining sequence */
  28    return ((bisearch(c, wide, sizeof(wide) / sizeof(struct interval) - 1)) ||
  29            (cjkwidth &&
  30             bisearch(c, ambiguous,
  31 @@ -1330,11 +1332,12 @@
  32  }
  33
  34  static void
  35 -comb_tofront(root, i)
  36 -int root, i;
  37 +comb_tofront(i)
  38 +int i;
  39  {
  40    for (;;)
  41      {
  42 +      int root = i >= 0x700 ? 0x801 : 0x800;
  43        debug1("bring to front: %x\n", i);
  44        combchars[combchars[i]->prev]->next = combchars[i]->next;
  45        combchars[combchars[i]->next]->prev = combchars[i]->prev;
  46 @@ -1396,9 +1399,9 @@
  47      {
  48        /* full, recycle old entry */
  49        if (c1 >= 0xd800 && c1 < 0xe000)
  50 -        comb_tofront(root, c1 - 0xd800);
  51 +        comb_tofront(c1 - 0xd800);
  52        i = combchars[root]->prev;
  53 -      if (c1 == i + 0xd800)
  54 +      if (i == 0x800 || i == 0x801 || c1 == i + 0xd800)
  55         {
  56           /* completely full, can't recycle */
  57           debug("utf8_handle_comp: completely full!\n");
  58 @@ -1422,7 +1425,7 @@
  59    mc->font  = (i >> 8) + 0xd8;
  60    mc->fontx = 0;
  61    debug3("combinig char %x %x -> %x\n", c1, c, i + 0xd800);
  62 -  comb_tofront(root, i);
  63 +  comb_tofront(i);
  64  }
  65
  66  #else /* !UTF8 */