From 1bd0b1aa0eefa779adaedaaaf400dee202da2ea7 Mon Sep 17 00:00:00 2001
From: Andrew Benson <abenson@gmail.com>
Date: Thu, 25 Feb 2021 18:03:09 -0600
Subject: [PATCH] screen: fix CVE-2021-26937

---
 srcpkgs/screen/patches/cve-2021-26937.patch | 64 +++++++++++++++++++++
 srcpkgs/screen/patches/utf8_nfd.patch       | 39 +++++++++++++
 srcpkgs/screen/template                     |  2 +-
 3 files changed, 104 insertions(+), 1 deletion(-)
 create mode 100644 srcpkgs/screen/patches/cve-2021-26937.patch
 create mode 100644 srcpkgs/screen/patches/utf8_nfd.patch

diff --git a/srcpkgs/screen/patches/cve-2021-26937.patch b/srcpkgs/screen/patches/cve-2021-26937.patch
new file mode 100644
index 00000000000..707e513e747
--- /dev/null
+++ b/srcpkgs/screen/patches/cve-2021-26937.patch
@@ -0,0 +1,64 @@
+Description: [CVE-2021-26937] Fix out of bounds array access
+Author: Michael Schröder <mls@suse.de>
+Bug-Debian: https://bugs.debian.org/982435
+Bug: https://savannah.gnu.org/bugs/?60030
+Bug: https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00000.html
+Bug-OSS-Security: https://www.openwall.com/lists/oss-security/2021/02/09/3
+Origin: https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00010.html
+
+--- encoding.c.orig
++++ encoding.c
+@@ -43,7 +43,7 @@
+ # ifdef UTF8
+ static int   recode_char __P((int, int, int));
+ static int   recode_char_to_encoding __P((int, int));
+-static void  comb_tofront __P((int, int));
++static void  comb_tofront __P((int));
+ #  ifdef DW_CHARS
+ static int   recode_char_dw __P((int, int *, int, int));
+ static int   recode_char_dw_to_encoding __P((int, int *, int));
+@@ -1263,6 +1263,8 @@
+     {0x30000, 0x3FFFD},
+   };
+ 
++  if (c >= 0xdf00 && c <= 0xdfff)
++    return 1;          /* dw combining sequence */
+   return ((bisearch(c, wide, sizeof(wide) / sizeof(struct interval) - 1)) ||
+           (cjkwidth &&
+            bisearch(c, ambiguous,
+@@ -1330,11 +1332,12 @@
+ }
+ 
+ static void
+-comb_tofront(root, i)
+-int root, i;
++comb_tofront(i)
++int i;
+ {
+   for (;;)
+     {
++      int root = i >= 0x700 ? 0x801 : 0x800;
+       debug1("bring to front: %x\n", i);
+       combchars[combchars[i]->prev]->next = combchars[i]->next;
+       combchars[combchars[i]->next]->prev = combchars[i]->prev;
+@@ -1396,9 +1399,9 @@
+     {
+       /* full, recycle old entry */
+       if (c1 >= 0xd800 && c1 < 0xe000)
+-        comb_tofront(root, c1 - 0xd800);
++        comb_tofront(c1 - 0xd800);
+       i = combchars[root]->prev;
+-      if (c1 == i + 0xd800)
++      if (i == 0x800 || i == 0x801 || c1 == i + 0xd800)
+ 	{
+ 	  /* completely full, can't recycle */
+ 	  debug("utf8_handle_comp: completely full!\n");
+@@ -1422,7 +1425,7 @@
+   mc->font  = (i >> 8) + 0xd8;
+   mc->fontx = 0;
+   debug3("combinig char %x %x -> %x\n", c1, c, i + 0xd800);
+-  comb_tofront(root, i);
++  comb_tofront(i);
+ }
+ 
+ #else /* !UTF8 */
diff --git a/srcpkgs/screen/patches/utf8_nfd.patch b/srcpkgs/screen/patches/utf8_nfd.patch
new file mode 100644
index 00000000000..6760abb9414
--- /dev/null
+++ b/srcpkgs/screen/patches/utf8_nfd.patch
@@ -0,0 +1,39 @@
+Author: Michael Schröder <mls@suse.de>
+Reviewed-By: Axel Beckert <abe@debian.org>
+Description: screen outputs screen "ÿ" after a connected character.
+ This is a character without the need. 
+ This happens in UTF-8 environment. 
+ Before : screen$ ruby1.9.1 -e 'puts "\u304b\u3099.."'
+          がÿ...
+ patch applied :  screen $ ruby1.9.1 -e 'puts "\u304b\u3099.."'
+          が..
+Origin: https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00012.html
+Bugs-Debian: https://bugs.debian.org/600246
+Bugs-Debian: https://bugs.debian.org/677512
+
+diff --git a/ansi.c b/ansi.c
+index 2a52edd..83b266d 100644
+--- ansi.c.orig
++++ ansi.c
+@@ -692,10 +692,6 @@ register int len;
+ 		    }
+ 		  curr->w_rend.font = 0;
+ 		}
+-#  ifdef DW_CHARS
+-	      if (curr->w_encoding == UTF8 && utf8_isdouble(c))
+-		curr->w_mbcs = 0xff;
+-#  endif
+ 	      if (curr->w_encoding == UTF8 && c >= 0x0300 && utf8_iscomb(c))
+ 		{
+ 		  int ox, oy;
+@@ -730,6 +726,10 @@ register int len;
+ 		    }
+ 		  break;
+ 		}
++#  ifdef DW_CHARS
++	      if (curr->w_encoding == UTF8 && utf8_isdouble(c))
++		curr->w_mbcs = 0xff;
++#  endif
+ 	      font = curr->w_rend.font;
+ # endif
+ # ifdef DW_CHARS
diff --git a/srcpkgs/screen/template b/srcpkgs/screen/template
index cac2f924ead..613696d9f37 100644
--- a/srcpkgs/screen/template
+++ b/srcpkgs/screen/template
@@ -1,7 +1,7 @@
 # Template file for 'screen'
 pkgname=screen
 version=4.8.0
-revision=1
+revision=2
 build_style=gnu-configure
 configure_args="--with-sys-screenrc=/etc/screenrc --enable-pam
  --enable-colors256 --enable-rxvt_osc --enable-telnet