[arch-commits] Commit in screen/trunk (CVE-2021-26937.patch PKGBUILD)

[Evangelos Foutras]

    Date: Thursday, March 4, 2021 @ 17:01:45
  Author: foutrelis
Revision: 409381

upgpkg: screen 4.8.0-3: add fix for CVE-2021-26937

Added:
  screen/trunk/CVE-2021-26937.patch
Modified:
  screen/trunk/PKGBUILD

----------------------+
 CVE-2021-26937.patch |   64 +++++++++++++++++++++++++++++++++++++++++++++++++
 PKGBUILD             |    9 ++++++
 2 files changed, 72 insertions(+), 1 deletion(-)

Added: CVE-2021-26937.patch
===================================================================
--- CVE-2021-26937.patch	                        (rev 0)
+++ CVE-2021-26937.patch	2021-03-04 17:01:45 UTC (rev 409381)
@@ -0,0 +1,64 @@
+Description: [CVE-2021-26937] Fix out of bounds array access
+Author: Michael Schröder <mls at 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
+
+--- a/encoding.c
++++ b/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 */

Modified: PKGBUILD
===================================================================
--- PKGBUILD	2021-03-04 16:18:44 UTC (rev 409380)
+++ PKGBUILD	2021-03-04 17:01:45 UTC (rev 409381)
@@ -4,7 +4,7 @@
 
 pkgname=screen
 pkgver=4.8.0
-pkgrel=2
+pkgrel=3
 pkgdesc='Full-screen window manager that multiplexes a physical terminal'
 url='https://www.gnu.org/software/screen/'
 arch=('x86_64')
@@ -13,10 +13,12 @@
 validpgpkeys=('2EE59A5D0C50167B5535BBF1B708A383C53EF3A4'
               '71AA09D9E8870FDB0AA7B61E21F968DEF747ABD7')
 source=("https://ftp.gnu.org/gnu/screen/screen-${pkgver}.tar.gz"{,.sig}
+        'CVE-2021-26937.patch'
         'tmpfiles.d'
         'pam.d')
 sha256sums=('6e11b13d8489925fde25dfb0935bf6ed71f9eb47eff233a181e078fde5655aa1'
             'SKIP'
+            '4ccc4d28da0f994aad165eb06119ecad7112cbb1401d73789af1b6c53e4819f5'
             '1f33ce4faca7bd05dd80403411af31e682d5d23e79558e884ae5a35f1dd96223'
             '971c25929ea97422c09e10679ab98e9e6c59295aae1a4a9970909d2206e23090')
 
@@ -25,6 +27,11 @@
 
 _ptygroup=5 #the UID of our PTY/TTY group
 
+prepare() {
+	cd "${srcdir}/${pkgname}-${pkgver}"
+	patch -Np1 -i ../CVE-2021-26937.patch
+}
+
 build() {
 	cd "${srcdir}/${pkgname}-${pkgver}"