fix for CVE-2020-10713

0001-yylex-Make-lexer-fatal-errors-actually-be-fatal.patch

@@ -0,0 +1,68 @@
+From a948ac01744f3490fa5af4b38039f7dade68bb3e Mon Sep 17 00:00:00 2001
+From: Peter Jones <pjones@redhat.com>
+Date: Wed, 15 Apr 2020 15:45:02 -0400
+Subject: [PATCH EMBARGOED CVE-2020-10713] yylex: Make lexer fatal errors
+ actually be fatal
+
+When presented with a command that can't be tokenized to anything
+smaller than YYLMAX characters, the parser calls YY_FATAL_ERROR(errmsg),
+expecting that will stop further processing, as such:
+
+  #define YY_DO_BEFORE_ACTION \
+        yyg->yytext_ptr = yy_bp; \
+        yyleng = (int) (yy_cp - yy_bp); \
+        yyg->yy_hold_char = *yy_cp; \
+        *yy_cp = '\0'; \
+        if ( yyleng >= YYLMAX ) \
+                YY_FATAL_ERROR( "token too large, exceeds YYLMAX" ); \
+        yy_flex_strncpy( yytext, yyg->yytext_ptr, yyleng + 1 , yyscanner); \
+        yyg->yy_c_buf_p = yy_cp;
+
+The code flex generates expects that YY_FATAL_ERROR() will either return
+for it or do some form of longjmp(), or handle the error in some way at
+least, and so the strncpy() call isn't in an "else" clause, and thus if
+YY_FATAL_ERROR() is *not* actually fatal, it does the call with the
+questionable limit, and predictable results ensue.
+
+Unfortunately, our implementation of YY_FATAL_ERROR() is:
+
+   #define YY_FATAL_ERROR(msg)                     \
+     do {                                          \
+       grub_printf (_("fatal error: %s\n"), _(msg));     \
+     } while (0)
+
+The same pattern exists in yyless(), and similar problems exist in users
+of YY_INPUT(), several places in the main parsing loop,
+yy_get_next_buffer(), yy_load_buffer_state(), yyensure_buffer_stack,
+yy_scan_buffer(), etc.
+
+All of these callers expect YY_FATAL_ERROR() to actually be fatal, and
+the things they do if it returns after calling it are wildly unsafe.
+
+Signed-off-by: Peter Jones <pjones@redhat.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/script/yylex.l | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/grub-core/script/yylex.l b/grub-core/script/yylex.l
+index 7b44c37b7..b7203c823 100644
+--- a/grub-core/script/yylex.l
++++ b/grub-core/script/yylex.l
+@@ -37,11 +37,11 @@
+ 
+ /* 
+  * As we don't have access to yyscanner, we cannot do much except to
+- * print the fatal error.
++ * print the fatal error and exit.
+  */
+ #define YY_FATAL_ERROR(msg)                     \
+   do {                                          \
+-    grub_printf (_("fatal error: %s\n"), _(msg));     \
++    grub_fatal (_("fatal error: %s\n"), _(msg));\
+   } while (0)
+ 
+ #define COPY(str, hint)                         \
+-- 
+2.11.0
+

grub.patches

@@ -251,6 +251,7 @@ Patch6008: normal-menu-Do-not-treat-error-values-as-key-presses.patch
 Patch6009: osdep-freebsd-Fix-partition-calculation-for-EBR-entr.patch
 Patch6010: 0001-CVE-2019-14865.patch
 Patch6011: 0002-CVE-2019-14865.patch
+Patch6012: 0001-yylex-Make-lexer-fatal-errors-actually-be-fatal.patch
 Patch9000: 0001-fix-grub-search-configfile-failed-in-net.patch
 Patch9001: Workaround-for-EFI-Bug-Plan3.patch
 Patch9002: revert-0067-Be-more-aggro.patch

grub2.spec

@@ -7,7 +7,7 @@
 Name:		grub2
 Epoch:		1
 Version:	2.02
-Release:	75
+Release:	76
 Summary:	Bootloader with support for Linux, Multiboot and more
 License:	GPLv3+
 URL:		http://www.gnu.org/software/grub/
@@ -361,6 +361,12 @@ fi
 %{_datadir}/man/man*
 
 %changelog
+* Fri Jul 31 2020 openEuler Buildteam <buildteam@openeuler.org> - 2.02-76
+- Type:cves
+- Id:CVE-2020-10713
+- SUG:NA
+- DESC:fix CVE-2020-10713
+
 * Fri Jun 5 2020 fengtao <fengtao40@huawei.com> - 2.02-75
 - remove sign for grub efi