From c250298fa3e60251dfbbb0df40b36c6d67bbea09 Mon Sep 17 00:00:00 2001 From: Josef Schlehofer Date: Tue, 23 Feb 2021 08:08:43 +0100 Subject: [PATCH] screen: backport fix for CVE-2021-26937 Security reports: - https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00000.html This issue can be reproduced even on OpenWrt - https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982435 Signed-off-by: Josef Schlehofer --- utils/screen/Makefile | 2 +- utils/screen/patches/001-CVE-2021-26937.patch | 64 +++++++++++++++++++ 2 files changed, 65 insertions(+), 1 deletion(-) create mode 100644 utils/screen/patches/001-CVE-2021-26937.patch diff --git a/utils/screen/Makefile b/utils/screen/Makefile index fc6f9c7b0..26a707c5d 100644 --- a/utils/screen/Makefile +++ b/utils/screen/Makefile @@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk PKG_NAME:=screen PKG_VERSION:=4.8.0 -PKG_RELEASE:=1 +PKG_RELEASE:=2 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz PKG_SOURCE_URL:=@GNU/screen diff --git a/utils/screen/patches/001-CVE-2021-26937.patch b/utils/screen/patches/001-CVE-2021-26937.patch new file mode 100644 index 000000000..3bc04cb8c --- /dev/null +++ b/utils/screen/patches/001-CVE-2021-26937.patch @@ -0,0 +1,64 @@ +Description: [CVE-2021-26937] Fix out of bounds array access +Author: Michael Schröder +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 @@ static int encmatch __P((char *, char * + # 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 @@ int c; + {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 @@ int c; + } + + 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 @@ struct mchar *mc; + { + /* 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 @@ struct mchar *mc; + 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 */