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From: "Armin Kuster" <akuster808@gmail.com>
To: Steve Sakoman <sakoman@gmail.com>
Cc: Patches and discussions about the oe-core layer
	<openembedded-core@lists.openembedded.org>,
	Armin Kuster <akuster@mvista.com>
Subject: Re: [OE-core] [dunfell][PATCH 2/2] grub2: Several cve fixes
Date: Mon, 6 Sep 2021 16:58:02 -0700	[thread overview]
Message-ID: <67057016-e1ee-5eb8-646d-2dcaee93d46e@gmail.com> (raw)
In-Reply-To: <CAGDS+nnNpHcBX7vFppKQ-is=n_A=7B-ziWXDy2wP4C8i_OEx9g@mail.gmail.com>



On 9/6/21 10:28 AM, Steve Sakoman wrote:
> On Sun, Sep 5, 2021 at 12:58 PM Armin Kuster <akuster808@gmail.com> wrote:
>> From: Armin Kuster <akuster@mvista.com>
>>
>> Source:  Debian.org
>> MR: 109156, 109169, 109336, 109349, 109362, 109375, 109388
>> Type: Security Fix https://sources.debian.org/patches/grub2/2.04-20/
>> Disposition: Backport from
>> ChangeID: f87f309a172004f21ac28870b85477cb90438d50
>> Description:
>>
>> Affects < 2.06
>>
>> Fixes these CVE's:
>> CVE-2020-14372
>> CVE-2020-25632
>> CVE-2020-25647
>> CVE-2020-27749
>> CVE-2020-27779
>> CVE-2021-20225
>> CVE-2021-20233
> This patch is causing autobuilder errors of this type:
>
> https://errors.yoctoproject.org/Errors/Details/603310/
ok. V2 out shortly.


>
> Dunfell's grub version seems to be missing grub_efi_secure_boot()
>
> Steve
>
>> Signed-off-by: Armin Kuster <akuster@mvista.com>
>> ---
>>  .../grub/files/CVE-2020-14372.patch           |  79 ++++
>>  .../grub/files/CVE-2020-14372_p1.patch        | 432 ++++++++++++++++++
>>  .../grub/files/CVE-2020-14372_p2.patch        |  60 +++
>>  .../grub/files/CVE-2020-14372_p3.patch        |  57 +++
>>  .../grub/files/CVE-2020-14372_p4.patch        | 168 +++++++
>>  .../grub/files/CVE-2020-25632.patch           |  90 ++++
>>  .../grub/files/CVE-2020-25647.patch           | 117 +++++
>>  .../grub/files/CVE-2020-27749_1.patch         |  80 ++++
>>  .../grub/files/CVE-2020-27749_2.patch         | 123 +++++
>>  .../grub/files/CVE-2020-27749_3.patch         |  69 +++
>>  .../grub/files/CVE-2020-27749_4.patch         |  97 ++++
>>  .../grub/files/CVE-2020-27749_5.patch         | 311 +++++++++++++
>>  .../grub/files/CVE-2020-27749_6.patch         | 254 ++++++++++
>>  .../grub/files/CVE-2020-27779.patch           |  72 +++
>>  .../grub/files/CVE-2021-20225.patch           |  57 +++
>>  .../grub/files/CVE-2021-20233.patch           |  50 ++
>>  meta/recipes-bsp/grub/grub2.inc               |  16 +
>>  17 files changed, 2132 insertions(+)
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-14372.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-14372_p1.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-14372_p2.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-14372_p3.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-14372_p4.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-25632.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-25647.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-27749_1.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-27749_2.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-27749_3.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-27749_4.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-27749_5.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-27749_6.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2020-27779.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2021-20225.patch
>>  create mode 100644 meta/recipes-bsp/grub/files/CVE-2021-20233.patch
>>
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-14372.patch b/meta/recipes-bsp/grub/files/CVE-2020-14372.patch
>> new file mode 100644
>> index 0000000000..cb51686ca5
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-14372.patch
>> @@ -0,0 +1,79 @@
>> +From b62501e6d869aa0968a17c8cb2379bde475dab20 Mon Sep 17 00:00:00 2001
>> +From: Javier Martinez Canillas <javierm@redhat.com>
>> +Date: Mon, 28 Sep 2020 20:08:41 +0200
>> +Subject: acpi: Don't register the acpi command when locked down
>> +MIME-Version: 1.0
>> +Content-Type: text/plain; charset=UTF-8
>> +Content-Transfer-Encoding: 8bit
>> +
>> +The command is not allowed when lockdown is enforced. Otherwise an
>> +attacker can instruct the GRUB to load an SSDT table to overwrite
>> +the kernel lockdown configuration and later load and execute
>> +unsigned code.
>> +
>> +Fixes: CVE-2020-14372
>> +
>> +Reported-by: Máté Kukri <km@mkukri.xyz>
>> +Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/006-acpi-Don-t-register-the-acpi-command-when-locked-down.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-14372
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + docs/grub.texi            |  5 +++++
>> + grub-core/commands/acpi.c | 15 ++++++++-------
>> + 2 files changed, 13 insertions(+), 7 deletions(-)
>> +
>> +Index: grub-2.04/docs/grub.texi
>> +===================================================================
>> +--- grub-2.04.orig/docs/grub.texi
>> ++++ grub-2.04/docs/grub.texi
>> +@@ -3986,6 +3986,11 @@ Normally, this command will replace the
>> + (RSDP) in the Extended BIOS Data Area to point to the new tables. If the
>> + @option{--no-ebda} option is used, the new tables will be known only to
>> + GRUB, but may be used by GRUB's EFI emulation.
>> ++
>> ++Note: The command is not allowed when lockdown is enforced (@pxref{Lockdown}).
>> ++      Otherwise an attacker can instruct the GRUB to load an SSDT table to
>> ++      overwrite the kernel lockdown configuration and later load and execute
>> ++      unsigned code.
>> + @end deffn
>> +
>> +
>> +Index: grub-2.04/grub-core/commands/acpi.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/commands/acpi.c
>> ++++ grub-2.04/grub-core/commands/acpi.c
>> +@@ -27,6 +27,7 @@
>> + #include <grub/mm.h>
>> + #include <grub/memory.h>
>> + #include <grub/i18n.h>
>> ++#include <grub/lockdown.h>
>> +
>> + #ifdef GRUB_MACHINE_EFI
>> + #include <grub/efi/efi.h>
>> +@@ -775,13 +776,13 @@ static grub_extcmd_t cmd;
>> +
>> + GRUB_MOD_INIT(acpi)
>> + {
>> +-  cmd = grub_register_extcmd ("acpi", grub_cmd_acpi, 0,
>> +-                            N_("[-1|-2] [--exclude=TABLE1,TABLE2|"
>> +-                            "--load-only=TABLE1,TABLE2] FILE1"
>> +-                            " [FILE2] [...]"),
>> +-                            N_("Load host ACPI tables and tables "
>> +-                            "specified by arguments."),
>> +-                            options);
>> ++  cmd = grub_register_extcmd_lockdown ("acpi", grub_cmd_acpi, 0,
>> ++                                       N_("[-1|-2] [--exclude=TABLE1,TABLE2|"
>> ++                                          "--load-only=TABLE1,TABLE2] FILE1"
>> ++                                          " [FILE2] [...]"),
>> ++                                       N_("Load host ACPI tables and tables "
>> ++                                          "specified by arguments."),
>> ++                                       options);
>> + }
>> +
>> + GRUB_MOD_FINI(acpi)
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-14372_p1.patch b/meta/recipes-bsp/grub/files/CVE-2020-14372_p1.patch
>> new file mode 100644
>> index 0000000000..47bbc594dc
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-14372_p1.patch
>> @@ -0,0 +1,432 @@
>> +From 4484c5c41f65b0975c0b300015764c0980765f0b Mon Sep 17 00:00:00 2001
>> +From: Javier Martinez Canillas <javierm@redhat.com>
>> +Date: Mon, 28 Sep 2020 20:08:02 +0200
>> +Subject: kern: Add lockdown support
>> +
>> +When the GRUB starts on a secure boot platform, some commands can be
>> +used to subvert the protections provided by the verification mechanism and
>> +could lead to booting untrusted system.
>> +
>> +To prevent that situation, allow GRUB to be locked down. That way the code
>> +may check if GRUB has been locked down and further restrict the commands
>> +that are registered or what subset of their functionality could be used.
>> +
>> +The lockdown support adds the following components:
>> +
>> +* The grub_lockdown() function which can be used to lockdown GRUB if,
>> +  e.g., UEFI Secure Boot is enabled.
>> +
>> +* The grub_is_lockdown() function which can be used to check if the GRUB
>> +  was locked down.
>> +
>> +* A verifier that flags OS kernels, the GRUB modules, Device Trees and ACPI
>> +  tables as GRUB_VERIFY_FLAGS_DEFER_AUTH to defer verification to other
>> +  verifiers. These files are only successfully verified if another registered
>> +  verifier returns success. Otherwise, the whole verification process fails.
>> +
>> +  For example, PE/COFF binaries verification can be done by the shim_lock
>> +  verifier which validates the signatures using the shim_lock protocol.
>> +  However, the verification is not deferred directly to the shim_lock verifier.
>> +  The shim_lock verifier is hooked into the verification process instead.
>> +
>> +* A set of grub_{command,extcmd}_lockdown functions that can be used by
>> +  code registering command handlers, to only register unsafe commands if
>> +  the GRUB has not been locked down.
>> +
>> +Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/002-kern-Add-lockdown-support.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-14372 Patch #1
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + conf/Makefile.common        |  2 +
>> + docs/grub-dev.texi          | 27 +++++++++++++
>> + docs/grub.texi              |  8 ++++
>> + grub-core/Makefile.am       |  5 ++-
>> + grub-core/Makefile.core.def |  1 +
>> + grub-core/commands/extcmd.c | 23 +++++++++++
>> + grub-core/kern/command.c    | 24 +++++++++++
>> + grub-core/kern/lockdown.c   | 80 +++++++++++++++++++++++++++++++++++++
>> + include/grub/command.h      |  5 +++
>> + include/grub/extcmd.h       |  7 ++++
>> + include/grub/lockdown.h     | 44 ++++++++++++++++++++
>> + 11 files changed, 225 insertions(+), 1 deletion(-)
>> + create mode 100644 grub-core/kern/lockdown.c
>> + create mode 100644 include/grub/lockdown.h
>> +
>> +Index: grub-2.04/conf/Makefile.common
>> +===================================================================
>> +--- grub-2.04.orig/conf/Makefile.common
>> ++++ grub-2.04/conf/Makefile.common
>> +@@ -84,7 +84,9 @@ CPPFLAGS_PARTTOOL_LIST = -Dgrub_parttool
>> + CPPFLAGS_TERMINAL_LIST = '-Dgrub_term_register_input(...)=INPUT_TERMINAL_LIST_MARKER(__VA_ARGS__)'
>> + CPPFLAGS_TERMINAL_LIST += '-Dgrub_term_register_output(...)=OUTPUT_TERMINAL_LIST_MARKER(__VA_ARGS__)'
>> + CPPFLAGS_COMMAND_LIST = '-Dgrub_register_command(...)=COMMAND_LIST_MARKER(__VA_ARGS__)'
>> ++CPPFLAGS_COMMAND_LIST += '-Dgrub_register_command_lockdown(...)=COMMAND_LOCKDOWN_LIST_MARKER(__VA_ARGS__)'
>> + CPPFLAGS_COMMAND_LIST += '-Dgrub_register_extcmd(...)=EXTCOMMAND_LIST_MARKER(__VA_ARGS__)'
>> ++CPPFLAGS_COMMAND_LIST += '-Dgrub_register_extcmd_lockdown(...)=EXTCOMMAND_LOCKDOWN_LIST_MARKER(__VA_ARGS__)'
>> + CPPFLAGS_COMMAND_LIST += '-Dgrub_register_command_p1(...)=P1COMMAND_LIST_MARKER(__VA_ARGS__)'
>> + CPPFLAGS_FDT_LIST := '-Dgrub_fdtbus_register(...)=FDT_DRIVER_LIST_MARKER(__VA_ARGS__)'
>> + CPPFLAGS_MARKER = $(CPPFLAGS_FS_LIST) $(CPPFLAGS_VIDEO_LIST) \
>> +Index: grub-2.04/docs/grub-dev.texi
>> +===================================================================
>> +--- grub-2.04.orig/docs/grub-dev.texi
>> ++++ grub-2.04/docs/grub-dev.texi
>> +@@ -86,6 +86,7 @@ This edition documents version @value{VE
>> + * PFF2 Font File Format::
>> + * Graphical Menu Software Design::
>> + * Verifiers framework::
>> ++* Lockdown framework::
>> + * Copying This Manual::         Copying This Manual
>> + * Index::
>> + @end menu
>> +@@ -2086,6 +2087,32 @@ Optionally at the end of the file @samp{
>> + the context. If you return no error during any of @samp{init}, @samp{write} and
>> + @samp{fini} then the file is considered as having succeded verification.
>> +
>> ++@node Lockdown framework
>> ++@chapter Lockdown framework
>> ++
>> ++The GRUB can be locked down, which is a restricted mode where some operations
>> ++are not allowed. For instance, some commands cannot be used when the GRUB is
>> ++locked down.
>> ++
>> ++The function
>> ++@code{grub_lockdown()} is used to lockdown GRUB and the function
>> ++@code{grub_is_lockdown()} function can be used to check whether lockdown is
>> ++enabled or not. When enabled, the function returns @samp{GRUB_LOCKDOWN_ENABLED}
>> ++and @samp{GRUB_LOCKDOWN_DISABLED} when is not enabled.
>> ++
>> ++The following functions can be used to register the commands that can only be
>> ++used when lockdown is disabled:
>> ++
>> ++@itemize
>> ++
>> ++@item @code{grub_cmd_lockdown()} registers command which should not run when the
>> ++GRUB is in lockdown mode.
>> ++
>> ++@item @code{grub_cmd_lockdown()} registers extended command which should not run
>> ++when the GRUB is in lockdown mode.
>> ++
>> ++@end itemize
>> ++
>> + @node Copying This Manual
>> + @appendix Copying This Manual
>> +
>> +Index: grub-2.04/docs/grub.texi
>> +===================================================================
>> +--- grub-2.04.orig/docs/grub.texi
>> ++++ grub-2.04/docs/grub.texi
>> +@@ -5581,6 +5581,7 @@ environment variables and commands are l
>> + * Using digital signatures::         Booting digitally signed code
>> + * UEFI secure boot and shim::        Booting digitally signed PE files
>> + * Measured Boot::                    Measuring boot components
>> ++* Lockdown::                         Lockdown when booting on a secure setup
>> + @end menu
>> +
>> + @node Authentication and authorisation
>> +@@ -5794,6 +5795,13 @@ into @file{core.img} in order to avoid a
>> +
>> + Measured boot is currently only supported on EFI platforms.
>> +
>> ++@node Lockdown
>> ++@section Lockdown when booting on a secure setup
>> ++
>> ++The GRUB can be locked down when booted on a secure boot environment, for example
>> ++if the UEFI secure boot is enabled. On a locked down configuration, the GRUB will
>> ++be restricted and some operations/commands cannot be executed.
>> ++
>> + @node Platform limitations
>> + @chapter Platform limitations
>> +
>> +Index: grub-2.04/grub-core/Makefile.am
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/Makefile.am
>> ++++ grub-2.04/grub-core/Makefile.am
>> +@@ -79,6 +79,7 @@ KERNEL_HEADER_FILES += $(top_srcdir)/inc
>> + KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/i18n.h
>> + KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/kernel.h
>> + KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/list.h
>> ++KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/lockdown.h
>> + KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/misc.h
>> + if COND_emu
>> + KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/compiler-rt-emu.h
>> +@@ -375,8 +376,10 @@ command.lst: $(MARKER_FILES)
>> +         b=`basename $$pp .marker`; \
>> +         sed -n \
>> +           -e "/EXTCOMMAND_LIST_MARKER *( *\"/{s/.*( *\"\([^\"]*\)\".*/*\1: $$b/;p;}" \
>> ++          -e "/EXTCOMMAND_LOCKDOWN_LIST_MARKER *( *\"/{s/.*( *\"\([^\"]*\)\".*/*\1: $$b/;p;}" \
>> +           -e "/P1COMMAND_LIST_MARKER *( *\"/{s/.*( *\"\([^\"]*\)\".*/*\1: $$b/;p;}" \
>> +-          -e "/COMMAND_LIST_MARKER *( *\"/{s/.*( *\"\([^\"]*\)\".*/\1: $$b/;p;}" $$pp; \
>> ++          -e "/COMMAND_LIST_MARKER *( *\"/{s/.*( *\"\([^\"]*\)\".*/\1: $$b/;p;}" \
>> ++          -e "/COMMAND_LOCKDOWN_LIST_MARKER *( *\"/{s/.*( *\"\([^\"]*\)\".*/\1: $$b/;p;}" $$pp; \
>> +       done) | sort -u > $@
>> + platform_DATA += command.lst
>> + CLEANFILES += command.lst
>> +Index: grub-2.04/grub-core/Makefile.core.def
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/Makefile.core.def
>> ++++ grub-2.04/grub-core/Makefile.core.def
>> +@@ -203,6 +203,7 @@ kernel = {
>> +   efi = term/efi/console.c;
>> +   efi = kern/acpi.c;
>> +   efi = kern/efi/acpi.c;
>> ++  efi = kern/lockdown.c;
>> +   i386_coreboot = kern/i386/pc/acpi.c;
>> +   i386_multiboot = kern/i386/pc/acpi.c;
>> +   i386_coreboot = kern/acpi.c;
>> +Index: grub-2.04/grub-core/commands/extcmd.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/commands/extcmd.c
>> ++++ grub-2.04/grub-core/commands/extcmd.c
>> +@@ -19,6 +19,7 @@
>> +
>> + #include <grub/mm.h>
>> + #include <grub/list.h>
>> ++#include <grub/lockdown.h>
>> + #include <grub/misc.h>
>> + #include <grub/extcmd.h>
>> + #include <grub/script_sh.h>
>> +@@ -110,6 +111,28 @@ grub_register_extcmd (const char *name,
>> +                                   summary, description, parser, 1);
>> + }
>> +
>> ++static grub_err_t
>> ++grub_extcmd_lockdown (grub_extcmd_context_t ctxt __attribute__ ((unused)),
>> ++                      int argc __attribute__ ((unused)),
>> ++                      char **argv __attribute__ ((unused)))
>> ++{
>> ++  return grub_error (GRUB_ERR_ACCESS_DENIED,
>> ++                     N_("%s: the command is not allowed when lockdown is enforced"),
>> ++                     ctxt->extcmd->cmd->name);
>> ++}
>> ++
>> ++grub_extcmd_t
>> ++grub_register_extcmd_lockdown (const char *name, grub_extcmd_func_t func,
>> ++                               grub_command_flags_t flags, const char *summary,
>> ++                               const char *description,
>> ++                               const struct grub_arg_option *parser)
>> ++{
>> ++  if (grub_is_lockdown () == GRUB_LOCKDOWN_ENABLED)
>> ++    func = grub_extcmd_lockdown;
>> ++
>> ++  return grub_register_extcmd (name, func, flags, summary, description, parser);
>> ++}
>> ++
>> + void
>> + grub_unregister_extcmd (grub_extcmd_t ext)
>> + {
>> +Index: grub-2.04/grub-core/kern/command.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/kern/command.c
>> ++++ grub-2.04/grub-core/kern/command.c
>> +@@ -17,6 +17,7 @@
>> +  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
>> +  */
>> +
>> ++#include <grub/lockdown.h>
>> + #include <grub/mm.h>
>> + #include <grub/command.h>
>> +
>> +@@ -77,6 +78,29 @@ grub_register_command_prio (const char *
>> +   return cmd;
>> + }
>> +
>> ++static grub_err_t
>> ++grub_cmd_lockdown (grub_command_t cmd __attribute__ ((unused)),
>> ++                   int argc __attribute__ ((unused)),
>> ++                   char **argv __attribute__ ((unused)))
>> ++
>> ++{
>> ++  return grub_error (GRUB_ERR_ACCESS_DENIED,
>> ++                     N_("%s: the command is not allowed when lockdown is enforced"),
>> ++                     cmd->name);
>> ++}
>> ++
>> ++grub_command_t
>> ++grub_register_command_lockdown (const char *name,
>> ++                                grub_command_func_t func,
>> ++                                const char *summary,
>> ++                                const char *description)
>> ++{
>> ++  if (grub_is_lockdown () == GRUB_LOCKDOWN_ENABLED)
>> ++    func = grub_cmd_lockdown;
>> ++
>> ++  return grub_register_command_prio (name, func, summary, description, 0);
>> ++}
>> ++
>> + void
>> + grub_unregister_command (grub_command_t cmd)
>> + {
>> +Index: grub-2.04/grub-core/kern/lockdown.c
>> +===================================================================
>> +--- /dev/null
>> ++++ grub-2.04/grub-core/kern/lockdown.c
>> +@@ -0,0 +1,80 @@
>> ++/*
>> ++ *  GRUB  --  GRand Unified Bootloader
>> ++ *  Copyright (C) 2020  Free Software Foundation, Inc.
>> ++ *
>> ++ *  GRUB is free software: you can redistribute it and/or modify
>> ++ *  it under the terms of the GNU General Public License as published by
>> ++ *  the Free Software Foundation, either version 3 of the License, or
>> ++ *  (at your option) any later version.
>> ++ *
>> ++ *  GRUB is distributed in the hope that it will be useful,
>> ++ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
>> ++ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> ++ *  GNU General Public License for more details.
>> ++ *
>> ++ *  You should have received a copy of the GNU General Public License
>> ++ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
>> ++ *
>> ++ */
>> ++
>> ++#include <grub/dl.h>
>> ++#include <grub/file.h>
>> ++#include <grub/lockdown.h>
>> ++#include <grub/verify.h>
>> ++
>> ++static int lockdown = GRUB_LOCKDOWN_DISABLED;
>> ++
>> ++static grub_err_t
>> ++lockdown_verifier_init (grub_file_t io __attribute__ ((unused)),
>> ++                    enum grub_file_type type,
>> ++                    void **context __attribute__ ((unused)),
>> ++                    enum grub_verify_flags *flags)
>> ++{
>> ++  *flags = GRUB_VERIFY_FLAGS_SKIP_VERIFICATION;
>> ++
>> ++  switch (type & GRUB_FILE_TYPE_MASK)
>> ++    {
>> ++    case GRUB_FILE_TYPE_GRUB_MODULE:
>> ++    case GRUB_FILE_TYPE_LINUX_KERNEL:
>> ++    case GRUB_FILE_TYPE_MULTIBOOT_KERNEL:
>> ++    case GRUB_FILE_TYPE_XEN_HYPERVISOR:
>> ++    case GRUB_FILE_TYPE_BSD_KERNEL:
>> ++    case GRUB_FILE_TYPE_XNU_KERNEL:
>> ++    case GRUB_FILE_TYPE_PLAN9_KERNEL:
>> ++    case GRUB_FILE_TYPE_NTLDR:
>> ++    case GRUB_FILE_TYPE_TRUECRYPT:
>> ++    case GRUB_FILE_TYPE_FREEDOS:
>> ++    case GRUB_FILE_TYPE_PXECHAINLOADER:
>> ++    case GRUB_FILE_TYPE_PCCHAINLOADER:
>> ++    case GRUB_FILE_TYPE_COREBOOT_CHAINLOADER:
>> ++    case GRUB_FILE_TYPE_EFI_CHAINLOADED_IMAGE:
>> ++    case GRUB_FILE_TYPE_ACPI_TABLE:
>> ++    case GRUB_FILE_TYPE_DEVICE_TREE_IMAGE:
>> ++      *flags = GRUB_VERIFY_FLAGS_DEFER_AUTH;
>> ++
>> ++      /* Fall through. */
>> ++
>> ++    default:
>> ++      return GRUB_ERR_NONE;
>> ++    }
>> ++}
>> ++
>> ++struct grub_file_verifier lockdown_verifier =
>> ++  {
>> ++    .name = "lockdown_verifier",
>> ++    .init = lockdown_verifier_init,
>> ++  };
>> ++
>> ++void
>> ++grub_lockdown (void)
>> ++{
>> ++  lockdown = GRUB_LOCKDOWN_ENABLED;
>> ++
>> ++  grub_verifier_register (&lockdown_verifier);
>> ++}
>> ++
>> ++int
>> ++grub_is_lockdown (void)
>> ++{
>> ++  return lockdown;
>> ++}
>> +Index: grub-2.04/include/grub/command.h
>> +===================================================================
>> +--- grub-2.04.orig/include/grub/command.h
>> ++++ grub-2.04/include/grub/command.h
>> +@@ -86,6 +86,11 @@ EXPORT_FUNC(grub_register_command_prio)
>> +                                        const char *summary,
>> +                                        const char *description,
>> +                                        int prio);
>> ++grub_command_t
>> ++EXPORT_FUNC(grub_register_command_lockdown) (const char *name,
>> ++                                             grub_command_func_t func,
>> ++                                             const char *summary,
>> ++                                             const char *description);
>> + void EXPORT_FUNC(grub_unregister_command) (grub_command_t cmd);
>> +
>> + static inline grub_command_t
>> +Index: grub-2.04/include/grub/extcmd.h
>> +===================================================================
>> +--- grub-2.04.orig/include/grub/extcmd.h
>> ++++ grub-2.04/include/grub/extcmd.h
>> +@@ -62,6 +62,13 @@ grub_extcmd_t EXPORT_FUNC(grub_register_
>> +                                                const char *description,
>> +                                                const struct grub_arg_option *parser);
>> +
>> ++grub_extcmd_t EXPORT_FUNC(grub_register_extcmd_lockdown) (const char *name,
>> ++                                                          grub_extcmd_func_t func,
>> ++                                                          grub_command_flags_t flags,
>> ++                                                          const char *summary,
>> ++                                                          const char *description,
>> ++                                                          const struct grub_arg_option *parser);
>> ++
>> + grub_extcmd_t EXPORT_FUNC(grub_register_extcmd_prio) (const char *name,
>> +                                                     grub_extcmd_func_t func,
>> +                                                     grub_command_flags_t flags,
>> +Index: grub-2.04/include/grub/lockdown.h
>> +===================================================================
>> +--- /dev/null
>> ++++ grub-2.04/include/grub/lockdown.h
>> +@@ -0,0 +1,44 @@
>> ++/*
>> ++ *  GRUB  --  GRand Unified Bootloader
>> ++ *  Copyright (C) 2020  Free Software Foundation, Inc.
>> ++ *
>> ++ *  GRUB is free software: you can redistribute it and/or modify
>> ++ *  it under the terms of the GNU General Public License as published by
>> ++ *  the Free Software Foundation, either version 3 of the License, or
>> ++ *  (at your option) any later version.
>> ++ *
>> ++ *  GRUB is distributed in the hope that it will be useful,
>> ++ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
>> ++ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> ++ *  GNU General Public License for more details.
>> ++ *
>> ++ *  You should have received a copy of the GNU General Public License
>> ++ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
>> ++ */
>> ++
>> ++#ifndef GRUB_LOCKDOWN_H
>> ++#define GRUB_LOCKDOWN_H 1
>> ++
>> ++#include <grub/symbol.h>
>> ++
>> ++#define GRUB_LOCKDOWN_DISABLED       0
>> ++#define GRUB_LOCKDOWN_ENABLED        1
>> ++
>> ++#ifdef GRUB_MACHINE_EFI
>> ++extern void
>> ++EXPORT_FUNC (grub_lockdown) (void);
>> ++extern int
>> ++EXPORT_FUNC (grub_is_lockdown) (void);
>> ++#else
>> ++static inline void
>> ++grub_lockdown (void)
>> ++{
>> ++}
>> ++
>> ++static inline int
>> ++grub_is_lockdown (void)
>> ++{
>> ++  return GRUB_LOCKDOWN_DISABLED;
>> ++}
>> ++#endif
>> ++#endif /* ! GRUB_LOCKDOWN_H */
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-14372_p2.patch b/meta/recipes-bsp/grub/files/CVE-2020-14372_p2.patch
>> new file mode 100644
>> index 0000000000..5dffbb1506
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-14372_p2.patch
>> @@ -0,0 +1,60 @@
>> +From fbcb8c44aa9136f9421f60d4d0bb9d055dc8c2eb Mon Sep 17 00:00:00 2001
>> +From: Javier Martinez Canillas <javierm@redhat.com>
>> +Date: Tue, 2 Feb 2021 19:59:48 +0100
>> +Subject: kern/lockdown: Set a variable if the GRUB is locked down
>> +
>> +It may be useful for scripts to determine whether the GRUB is locked
>> +down or not. Add the lockdown variable which is set to "y" when the GRUB
>> +is locked down.
>> +
>> +Suggested-by: Dimitri John Ledkov <xnox@ubuntu.com>
>> +Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/003-kern-lockdown-Set-a-variable-if-the-GRUB-is-locked-down.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-14372 Patch #2
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + docs/grub.texi            | 3 +++
>> + grub-core/kern/lockdown.c | 4 ++++
>> + 2 files changed, 7 insertions(+)
>> +
>> +Index: grub-2.04/docs/grub.texi
>> +===================================================================
>> +--- grub-2.04.orig/docs/grub.texi
>> ++++ grub-2.04/docs/grub.texi
>> +@@ -5802,6 +5802,9 @@ The GRUB can be locked down when booted
>> + if the UEFI secure boot is enabled. On a locked down configuration, the GRUB will
>> + be restricted and some operations/commands cannot be executed.
>> +
>> ++The @samp{lockdown} variable is set to @samp{y} when the GRUB is locked down.
>> ++Otherwise it does not exit.
>> ++
>> + @node Platform limitations
>> + @chapter Platform limitations
>> +
>> +Index: grub-2.04/grub-core/kern/lockdown.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/kern/lockdown.c
>> ++++ grub-2.04/grub-core/kern/lockdown.c
>> +@@ -18,6 +18,7 @@
>> +  */
>> +
>> + #include <grub/dl.h>
>> ++#include <grub/env.h>
>> + #include <grub/file.h>
>> + #include <grub/lockdown.h>
>> + #include <grub/verify.h>
>> +@@ -71,6 +72,9 @@ grub_lockdown (void)
>> +   lockdown = GRUB_LOCKDOWN_ENABLED;
>> +
>> +   grub_verifier_register (&lockdown_verifier);
>> ++
>> ++  grub_env_set ("lockdown", "y");
>> ++  grub_env_export ("lockdown");
>> + }
>> +
>> + int
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-14372_p3.patch b/meta/recipes-bsp/grub/files/CVE-2020-14372_p3.patch
>> new file mode 100644
>> index 0000000000..2a8f1ed6d6
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-14372_p3.patch
>> @@ -0,0 +1,57 @@
>> +From 0260afe3d0b3fe07a2c55eaf3582a21a35bfd4f5 Mon Sep 17 00:00:00 2001
>> +From: Javier Martinez Canillas <javierm@redhat.com>
>> +Date: Mon, 28 Sep 2020 20:08:29 +0200
>> +Subject: efi: Lockdown the GRUB when the UEFI Secure Boot is enabled
>> +
>> +If the UEFI Secure Boot is enabled then the GRUB must be locked down
>> +to prevent executing code that can potentially be used to subvert its
>> +verification mechanisms.
>> +
>> +Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/004-efi-Lockdown-the-GRUB-when-the-UEFI-Secure-Boot-is-enabled.patch
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-14372 Patch #3
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + grub-core/kern/efi/init.c | 18 ++++++++++++++++++
>> + 1 file changed, 18 insertions(+)
>> +
>> +diff --git a/grub-core/kern/efi/init.c b/grub-core/kern/efi/init.c
>> +index 2c31847bf..811692054 100644
>> +--- a/grub-core/kern/efi/init.c
>> ++++ b/grub-core/kern/efi/init.c
>> +@@ -20,6 +20,7 @@
>> + #include <grub/efi/efi.h>
>> + #include <grub/efi/console.h>
>> + #include <grub/efi/disk.h>
>> ++#include <grub/lockdown.h>
>> + #include <grub/term.h>
>> + #include <grub/misc.h>
>> + #include <grub/env.h>
>> +@@ -39,6 +40,23 @@ grub_efi_init (void)
>> +   /* Initialize the memory management system.  */
>> +   grub_efi_mm_init ();
>> +
>> ++  /*
>> ++   * Lockdown the GRUB and register the shim_lock verifier
>> ++   * if the UEFI Secure Boot is enabled.
>> ++   */
>> ++  if (grub_efi_secure_boot ())
>> ++    {
>> ++      grub_lockdown ();
>> ++
>> ++      /*
>> ++       * TODO: Move Debian to using the shim_lock verifier and
>> ++       * enable the lockdown verifier.
>> ++       */
>> ++#if 0
>> ++      grub_shim_lock_verifier_setup ();
>> ++#endif
>> ++    }
>> ++
>> +   efi_call_4 (grub_efi_system_table->boot_services->set_watchdog_timer,
>> +             0, 0, 0, NULL);
>> +
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-14372_p4.patch b/meta/recipes-bsp/grub/files/CVE-2020-14372_p4.patch
>> new file mode 100644
>> index 0000000000..486c9f76aa
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-14372_p4.patch
>> @@ -0,0 +1,168 @@
>> +From bcffa66a873f72f337eb79d4ce673b2db8b3e7b0 Mon Sep 17 00:00:00 2001
>> +From: Javier Martinez Canillas <javierm@redhat.com>
>> +Date: Mon, 28 Sep 2020 20:08:33 +0200
>> +Subject: efi: Use grub_is_lockdown() instead of hardcoding a disabled modules
>> + list
>> +
>> +Now the GRUB can check if it has been locked down and this can be used to
>> +prevent executing commands that can be utilized to circumvent the UEFI
>> +Secure Boot mechanisms. So, instead of hardcoding a list of modules that
>> +have to be disabled, prevent the usage of commands that can be dangerous.
>> +
>> +This not only allows the commands to be disabled on other platforms, but
>> +also properly separate the concerns. Since the shim_lock verifier logic
>> +should be only about preventing to run untrusted binaries and not about
>> +defining these kind of policies.
>> +
>> +Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/005-efi-Use-grub_is_lockdown-instead-of-hardcoding-a-disabled-modules-list.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-14372 Patch #4
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + docs/grub.texi                  | 17 ++++++++++-------
>> + grub-core/commands/i386/wrmsr.c |  5 +++--
>> + grub-core/commands/iorw.c       | 19 ++++++++++---------
>> + grub-core/commands/memrw.c      | 19 ++++++++++---------
>> + 4 files changed, 33 insertions(+), 27 deletions(-)
>> +
>> +Index: grub-2.04/docs/grub.texi
>> +===================================================================
>> +--- grub-2.04.orig/docs/grub.texi
>> ++++ grub-2.04/docs/grub.texi
>> +@@ -5256,6 +5256,9 @@ only applies to the particular cpu/core/
>> + Also, if you specify a reserved or unimplemented MSR address, it will
>> + cause a general protection exception (which is not currently being handled)
>> + and the system will reboot.
>> ++
>> ++Note: The command is not allowed when lockdown is enforced (@pxref{Lockdown}).
>> ++      This is done to prevent subverting various security mechanisms.
>> + @end deffn
>> +
>> + @node xen_hypervisor
>> +@@ -5750,13 +5753,13 @@ secure boot chain.
>> + The GRUB, except the @command{chainloader} command, works with the UEFI secure
>> + boot and the shim. This functionality is provided by the shim_lock module. It
>> + is recommend to build in this and other required modules into the @file{core.img}.
>> +-All modules not stored in the @file{core.img} and the ACPI tables for the
>> +-@command{acpi} command have to be signed, e.g. using PGP. Additionally, the
>> +-@command{iorw}, the @command{memrw} and the @command{wrmsr} commands are
>> +-prohibited if the UEFI secure boot is enabled. This is done due to
>> +-security reasons. All above mentioned requirements are enforced by the
>> +-shim_lock module. And itself it is a persistent module which means that
>> +-it cannot be unloaded if it was loaded into the memory.
>> ++
>> ++All GRUB modules not stored in the @file{core.img}, OS kernels, ACPI tables,
>> ++Device Trees, etc. have to be signed, e.g, using PGP. Additionally, the commands
>> ++that can be used to subvert the UEFI secure boot mechanism, such as @command{iorw}
>> ++and @command{memrw} will not be available when the UEFI secure boot is enabled.
>> ++This is done for security reasons and are enforced by the GRUB Lockdown mechanism
>> ++(@pxref{Lockdown}).
>> +
>> + @node Measured Boot
>> + @section Measuring boot components
>> +Index: grub-2.04/grub-core/commands/i386/wrmsr.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/commands/i386/wrmsr.c
>> ++++ grub-2.04/grub-core/commands/i386/wrmsr.c
>> +@@ -24,6 +24,7 @@
>> + #include <grub/env.h>
>> + #include <grub/command.h>
>> + #include <grub/extcmd.h>
>> ++#include <grub/lockdown.h>
>> + #include <grub/i18n.h>
>> + #include <grub/i386/cpuid.h>
>> + #include <grub/i386/wrmsr.h>
>> +@@ -83,8 +84,8 @@ grub_cmd_msr_write (grub_command_t cmd _
>> +
>> + GRUB_MOD_INIT(wrmsr)
>> + {
>> +-  cmd_write = grub_register_command ("wrmsr", grub_cmd_msr_write, N_("ADDR VALUE"),
>> +-                                   N_("Write a value to a CPU model specific register."));
>> ++  cmd_write = grub_register_command_lockdown ("wrmsr", grub_cmd_msr_write, N_("ADDR VALUE"),
>> ++                                              N_("Write a value to a CPU model specific register."));
>> + }
>> +
>> + GRUB_MOD_FINI(wrmsr)
>> +Index: grub-2.04/grub-core/commands/iorw.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/commands/iorw.c
>> ++++ grub-2.04/grub-core/commands/iorw.c
>> +@@ -23,6 +23,7 @@
>> + #include <grub/env.h>
>> + #include <grub/cpu/io.h>
>> + #include <grub/i18n.h>
>> ++#include <grub/lockdown.h>
>> +
>> + GRUB_MOD_LICENSE ("GPLv3+");
>> +
>> +@@ -131,17 +132,17 @@ GRUB_MOD_INIT(memrw)
>> +                         N_("PORT"), N_("Read 32-bit value from PORT."),
>> +                         options);
>> +   cmd_write_byte =
>> +-    grub_register_command ("outb", grub_cmd_write,
>> +-                         N_("PORT VALUE [MASK]"),
>> +-                         N_("Write 8-bit VALUE to PORT."));
>> ++    grub_register_command_lockdown ("outb", grub_cmd_write,
>> ++                                    N_("PORT VALUE [MASK]"),
>> ++                                    N_("Write 8-bit VALUE to PORT."));
>> +   cmd_write_word =
>> +-    grub_register_command ("outw", grub_cmd_write,
>> +-                         N_("PORT VALUE [MASK]"),
>> +-                         N_("Write 16-bit VALUE to PORT."));
>> ++    grub_register_command_lockdown ("outw", grub_cmd_write,
>> ++                                    N_("PORT VALUE [MASK]"),
>> ++                                    N_("Write 16-bit VALUE to PORT."));
>> +   cmd_write_dword =
>> +-    grub_register_command ("outl", grub_cmd_write,
>> +-                         N_("ADDR VALUE [MASK]"),
>> +-                         N_("Write 32-bit VALUE to PORT."));
>> ++    grub_register_command_lockdown ("outl", grub_cmd_write,
>> ++                                    N_("ADDR VALUE [MASK]"),
>> ++                                    N_("Write 32-bit VALUE to PORT."));
>> + }
>> +
>> + GRUB_MOD_FINI(memrw)
>> +Index: grub-2.04/grub-core/commands/memrw.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/commands/memrw.c
>> ++++ grub-2.04/grub-core/commands/memrw.c
>> +@@ -22,6 +22,7 @@
>> + #include <grub/extcmd.h>
>> + #include <grub/env.h>
>> + #include <grub/i18n.h>
>> ++#include <grub/lockdown.h>
>> +
>> + GRUB_MOD_LICENSE ("GPLv3+");
>> +
>> +@@ -133,17 +134,17 @@ GRUB_MOD_INIT(memrw)
>> +                         N_("ADDR"), N_("Read 32-bit value from ADDR."),
>> +                         options);
>> +   cmd_write_byte =
>> +-    grub_register_command ("write_byte", grub_cmd_write,
>> +-                         N_("ADDR VALUE [MASK]"),
>> +-                         N_("Write 8-bit VALUE to ADDR."));
>> ++    grub_register_command_lockdown ("write_byte", grub_cmd_write,
>> ++                                    N_("ADDR VALUE [MASK]"),
>> ++                                    N_("Write 8-bit VALUE to ADDR."));
>> +   cmd_write_word =
>> +-    grub_register_command ("write_word", grub_cmd_write,
>> +-                         N_("ADDR VALUE [MASK]"),
>> +-                         N_("Write 16-bit VALUE to ADDR."));
>> ++    grub_register_command_lockdown ("write_word", grub_cmd_write,
>> ++                                    N_("ADDR VALUE [MASK]"),
>> ++                                    N_("Write 16-bit VALUE to ADDR."));
>> +   cmd_write_dword =
>> +-    grub_register_command ("write_dword", grub_cmd_write,
>> +-                         N_("ADDR VALUE [MASK]"),
>> +-                         N_("Write 32-bit VALUE to ADDR."));
>> ++    grub_register_command_lockdown ("write_dword", grub_cmd_write,
>> ++                                    N_("ADDR VALUE [MASK]"),
>> ++                                    N_("Write 32-bit VALUE to ADDR."));
>> + }
>> +
>> + GRUB_MOD_FINI(memrw)
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-25632.patch b/meta/recipes-bsp/grub/files/CVE-2020-25632.patch
>> new file mode 100644
>> index 0000000000..30a6997185
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-25632.patch
>> @@ -0,0 +1,90 @@
>> +From 1e3203e7ec93ba725eb27bd28210a42430bf6539 Mon Sep 17 00:00:00 2001
>> +From: Javier Martinez Canillas <javierm@redhat.com>
>> +Date: Tue, 29 Sep 2020 14:08:55 +0200
>> +Subject: dl: Only allow unloading modules that are not dependencies
>> +
>> +When a module is attempted to be removed its reference counter is always
>> +decremented. This means that repeated rmmod invocations will cause the
>> +module to be unloaded even if another module depends on it.
>> +
>> +This may lead to a use-after-free scenario allowing an attacker to execute
>> +arbitrary code and by-pass the UEFI Secure Boot protection.
>> +
>> +While being there, add the extern keyword to some function declarations in
>> +that header file.
>> +
>> +Fixes: CVE-2020-25632
>> +
>> +Reported-by: Chris Coulson <chris.coulson@canonical.com>
>> +Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/014-dl-Only-allow-unloading-modules-that-are-not-dependencies.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-25632
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + grub-core/commands/minicmd.c | 7 +++++--
>> + grub-core/kern/dl.c          | 9 +++++++++
>> + include/grub/dl.h            | 8 +++++---
>> + 3 files changed, 19 insertions(+), 5 deletions(-)
>> +
>> +Index: grub-2.04/grub-core/commands/minicmd.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/commands/minicmd.c
>> ++++ grub-2.04/grub-core/commands/minicmd.c
>> +@@ -140,8 +140,11 @@ grub_mini_cmd_rmmod (struct grub_command
>> +   if (grub_dl_is_persistent (mod))
>> +     return grub_error (GRUB_ERR_BAD_ARGUMENT, "cannot unload persistent module");
>> +
>> +-  if (grub_dl_unref (mod) <= 0)
>> +-    grub_dl_unload (mod);
>> ++  if (grub_dl_ref_count (mod) > 1)
>> ++    return grub_error (GRUB_ERR_BAD_ARGUMENT, "cannot unload referenced module");
>> ++
>> ++  grub_dl_unref (mod);
>> ++  grub_dl_unload (mod);
>> +
>> +   return 0;
>> + }
>> +Index: grub-2.04/grub-core/kern/dl.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/kern/dl.c
>> ++++ grub-2.04/grub-core/kern/dl.c
>> +@@ -549,6 +549,15 @@ grub_dl_unref (grub_dl_t mod)
>> +   return --mod->ref_count;
>> + }
>> +
>> ++int
>> ++grub_dl_ref_count (grub_dl_t mod)
>> ++{
>> ++  if (mod == NULL)
>> ++    return 0;
>> ++
>> ++  return mod->ref_count;
>> ++}
>> ++
>> + static void
>> + grub_dl_flush_cache (grub_dl_t mod)
>> + {
>> +Index: grub-2.04/include/grub/dl.h
>> +===================================================================
>> +--- grub-2.04.orig/include/grub/dl.h
>> ++++ grub-2.04/include/grub/dl.h
>> +@@ -203,9 +203,11 @@ grub_dl_t EXPORT_FUNC(grub_dl_load) (con
>> + grub_dl_t grub_dl_load_core (void *addr, grub_size_t size);
>> + grub_dl_t EXPORT_FUNC(grub_dl_load_core_noinit) (void *addr, grub_size_t size);
>> + int EXPORT_FUNC(grub_dl_unload) (grub_dl_t mod);
>> +-void grub_dl_unload_unneeded (void);
>> +-int EXPORT_FUNC(grub_dl_ref) (grub_dl_t mod);
>> +-int EXPORT_FUNC(grub_dl_unref) (grub_dl_t mod);
>> ++extern void grub_dl_unload_unneeded (void);
>> ++extern int EXPORT_FUNC(grub_dl_ref) (grub_dl_t mod);
>> ++extern int EXPORT_FUNC(grub_dl_unref) (grub_dl_t mod);
>> ++extern int EXPORT_FUNC(grub_dl_ref_count) (grub_dl_t mod);
>> ++
>> + extern grub_dl_t EXPORT_VAR(grub_dl_head);
>> +
>> + #ifndef GRUB_UTIL
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-25647.patch b/meta/recipes-bsp/grub/files/CVE-2020-25647.patch
>> new file mode 100644
>> index 0000000000..73b2abadf3
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-25647.patch
>> @@ -0,0 +1,117 @@
>> +From 98a777237f96dcf82a01d42c887015f6bc45174f Mon Sep 17 00:00:00 2001
>> +From: Javier Martinez Canillas <javierm@redhat.com>
>> +Date: Fri, 11 Dec 2020 19:19:21 +0100
>> +Subject: usb: Avoid possible out-of-bound accesses caused by malicious devices
>> +
>> +The maximum number of configurations and interfaces are fixed but there is
>> +no out-of-bound checking to prevent a malicious USB device to report large
>> +values for these and cause accesses outside the arrays' memory.
>> +
>> +Fixes: CVE-2020-25647
>> +
>> +Reported-by: Joseph Tartaro (IOActive)
>> +Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
>> +Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/015-usb-Avoid-possible-out-of-bound-accesses-caused-by-malicious-devices.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-25647
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +---
>> + grub-core/bus/usb/usb.c | 15 ++++++++++++---
>> + include/grub/usb.h      | 10 +++++++---
>> + 2 files changed, 19 insertions(+), 6 deletions(-)
>> +
>> +diff --git a/grub-core/bus/usb/usb.c b/grub-core/bus/usb/usb.c
>> +index 8da5e4c74..7cb3cc230 100644
>> +--- a/grub-core/bus/usb/usb.c
>> ++++ b/grub-core/bus/usb/usb.c
>> +@@ -75,6 +75,9 @@ grub_usb_controller_iterate (grub_usb_controller_iterate_hook_t hook,
>> + grub_usb_err_t
>> + grub_usb_clear_halt (grub_usb_device_t dev, int endpoint)
>> + {
>> ++  if (endpoint >= GRUB_USB_MAX_TOGGLE)
>> ++    return GRUB_USB_ERR_BADDEVICE;
>> ++
>> +   dev->toggle[endpoint] = 0;
>> +   return grub_usb_control_msg (dev, (GRUB_USB_REQTYPE_OUT
>> +                                    | GRUB_USB_REQTYPE_STANDARD
>> +@@ -134,10 +137,10 @@ grub_usb_device_initialize (grub_usb_device_t dev)
>> +     return err;
>> +   descdev = &dev->descdev;
>> +
>> +-  for (i = 0; i < 8; i++)
>> ++  for (i = 0; i < GRUB_USB_MAX_CONF; i++)
>> +     dev->config[i].descconf = NULL;
>> +
>> +-  if (descdev->configcnt == 0)
>> ++  if (descdev->configcnt == 0 || descdev->configcnt > GRUB_USB_MAX_CONF)
>> +     {
>> +       err = GRUB_USB_ERR_BADDEVICE;
>> +       goto fail;
>> +@@ -172,6 +175,12 @@ grub_usb_device_initialize (grub_usb_device_t dev)
>> +       /* Skip the configuration descriptor.  */
>> +       pos = dev->config[i].descconf->length;
>> +
>> ++      if (dev->config[i].descconf->numif > GRUB_USB_MAX_IF)
>> ++        {
>> ++          err = GRUB_USB_ERR_BADDEVICE;
>> ++          goto fail;
>> ++        }
>> ++
>> +       /* Read all interfaces.  */
>> +       for (currif = 0; currif < dev->config[i].descconf->numif; currif++)
>> +       {
>> +@@ -217,7 +226,7 @@ grub_usb_device_initialize (grub_usb_device_t dev)
>> +
>> +  fail:
>> +
>> +-  for (i = 0; i < 8; i++)
>> ++  for (i = 0; i < GRUB_USB_MAX_CONF; i++)
>> +     grub_free (dev->config[i].descconf);
>> +
>> +   return err;
>> +diff --git a/include/grub/usb.h b/include/grub/usb.h
>> +index 512ae1dd0..6475c552f 100644
>> +--- a/include/grub/usb.h
>> ++++ b/include/grub/usb.h
>> +@@ -23,6 +23,10 @@
>> + #include <grub/usbdesc.h>
>> + #include <grub/usbtrans.h>
>> +
>> ++#define GRUB_USB_MAX_CONF    8
>> ++#define GRUB_USB_MAX_IF      32
>> ++#define GRUB_USB_MAX_TOGGLE  256
>> ++
>> + typedef struct grub_usb_device *grub_usb_device_t;
>> + typedef struct grub_usb_controller *grub_usb_controller_t;
>> + typedef struct grub_usb_controller_dev *grub_usb_controller_dev_t;
>> +@@ -167,7 +171,7 @@ struct grub_usb_configuration
>> +   struct grub_usb_desc_config *descconf;
>> +
>> +   /* Interfaces associated to this configuration.  */
>> +-  struct grub_usb_interface interf[32];
>> ++  struct grub_usb_interface interf[GRUB_USB_MAX_IF];
>> + };
>> +
>> + struct grub_usb_hub_port
>> +@@ -191,7 +195,7 @@ struct grub_usb_device
>> +   struct grub_usb_controller controller;
>> +
>> +   /* Device configurations (after opening the device).  */
>> +-  struct grub_usb_configuration config[8];
>> ++  struct grub_usb_configuration config[GRUB_USB_MAX_CONF];
>> +
>> +   /* Device address.  */
>> +   int addr;
>> +@@ -203,7 +207,7 @@ struct grub_usb_device
>> +   int initialized;
>> +
>> +   /* Data toggle values (used for bulk transfers only).  */
>> +-  int toggle[256];
>> ++  int toggle[GRUB_USB_MAX_TOGGLE];
>> +
>> +   /* Used by libusb wrapper.  Schedulded for removal. */
>> +   void *data;
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-27749_1.patch b/meta/recipes-bsp/grub/files/CVE-2020-27749_1.patch
>> new file mode 100644
>> index 0000000000..2cc07186f7
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-27749_1.patch
>> @@ -0,0 +1,80 @@
>> +From 8d06222bb8fb5d610dcdadb221d1846e7de88980 Mon Sep 17 00:00:00 2001
>> +From: Chris Coulson <chris.coulson@canonical.com>
>> +Date: Wed, 18 Nov 2020 00:59:24 +0000
>> +Subject: kern/parser: Fix a memory leak
>> +
>> +The getline() function supplied to grub_parser_split_cmdline() returns
>> +a newly allocated buffer and can be called multiple times, but the
>> +returned buffer is never freed.
>> +
>> +Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/093-kern-parser-Fix-a-memory-leak.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-27749 patch#1
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + grub-core/kern/parser.c | 20 ++++++++++++++++----
>> + 1 file changed, 16 insertions(+), 4 deletions(-)
>> +
>> +Index: grub-2.04/grub-core/kern/parser.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/kern/parser.c
>> ++++ grub-2.04/grub-core/kern/parser.c
>> +@@ -140,6 +140,7 @@ grub_parser_split_cmdline (const char *c
>> +   char buffer[1024];
>> +   char *bp = buffer;
>> +   char *rd = (char *) cmdline;
>> ++  char *rp = rd;
>> +   char varname[200];
>> +   char *vp = varname;
>> +   char *args;
>> +@@ -148,10 +149,18 @@ grub_parser_split_cmdline (const char *c
>> +   *argc = 0;
>> +   do
>> +     {
>> +-      if (!rd || !*rd)
>> ++      if (rp == NULL || *rp == '\0')
>> +       {
>> ++        if (rd != cmdline)
>> ++          {
>> ++            grub_free (rd);
>> ++            rd = rp = NULL;
>> ++          }
>> +         if (getline)
>> +-          getline (&rd, 1, getline_data);
>> ++          {
>> ++            getline (&rd, 1, getline_data);
>> ++            rp = rd;
>> ++          }
>> +         else
>> +           break;
>> +       }
>> +@@ -159,12 +168,12 @@ grub_parser_split_cmdline (const char *c
>> +       if (!rd)
>> +       break;
>> +
>> +-      for (; *rd; rd++)
>> ++      for (; *rp != '\0'; rp++)
>> +       {
>> +         grub_parser_state_t newstate;
>> +         char use;
>> +
>> +-        newstate = grub_parser_cmdline_state (state, *rd, &use);
>> ++        newstate = grub_parser_cmdline_state (state, *rp, &use);
>> +
>> +         /* If a variable was being processed and this character does
>> +            not describe the variable anymore, write the variable to
>> +@@ -197,6 +206,9 @@ grub_parser_split_cmdline (const char *c
>> +     }
>> +   while (state != GRUB_PARSER_STATE_TEXT && !check_varstate (state));
>> +
>> ++  if (rd != cmdline)
>> ++    grub_free (rd);
>> ++
>> +   /* A special case for when the last character was part of a
>> +      variable.  */
>> +   add_var (varname, &bp, &vp, state, GRUB_PARSER_STATE_TEXT);
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-27749_2.patch b/meta/recipes-bsp/grub/files/CVE-2020-27749_2.patch
>> new file mode 100644
>> index 0000000000..88a780bcec
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-27749_2.patch
>> @@ -0,0 +1,123 @@
>> +From 45812770ce81194ede99bba4c868b3a244fc37ee Mon Sep 17 00:00:00 2001
>> +From: Chris Coulson <chris.coulson@canonical.com>
>> +Date: Tue, 5 Jan 2021 22:17:28 +0000
>> +Subject: kern/parser: Introduce process_char() helper
>> +
>> +grub_parser_split_cmdline() iterates over each command line character.
>> +In order to add error checking and to simplify the subsequent error
>> +handling, split the character processing in to a separate function.
>> +
>> +Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/094-kern-parser-Introduce-process_char-helper.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-27749 patch#2
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + grub-core/kern/parser.c | 74 +++++++++++++++++++++++++----------------
>> + 1 file changed, 46 insertions(+), 28 deletions(-)
>> +
>> +Index: grub-2.04/grub-core/kern/parser.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/kern/parser.c
>> ++++ grub-2.04/grub-core/kern/parser.c
>> +@@ -1,7 +1,7 @@
>> + /* parser.c - the part of the parser that can return partial tokens */
>> + /*
>> +  *  GRUB  --  GRand Unified Bootloader
>> +- *  Copyright (C) 2005,2007,2009  Free Software Foundation, Inc.
>> ++ *  Copyright (C) 2005,2007,2009,2021  Free Software Foundation, Inc.
>> +  *
>> +  *  GRUB is free software: you can redistribute it and/or modify
>> +  *  it under the terms of the GNU General Public License as published by
>> +@@ -129,6 +129,46 @@ add_var (char *varname, char **bp, char
>> +     *((*bp)++) = *val;
>> + }
>> +
>> ++static grub_err_t
>> ++process_char (char c, char *buffer, char **bp, char *varname, char **vp,
>> ++            grub_parser_state_t state, int *argc,
>> ++            grub_parser_state_t *newstate)
>> ++{
>> ++  char use;
>> ++
>> ++  *newstate = grub_parser_cmdline_state (state, c, &use);
>> ++
>> ++  /*
>> ++   * If a variable was being processed and this character does
>> ++   * not describe the variable anymore, write the variable to
>> ++   * the buffer.
>> ++   */
>> ++  add_var (varname, bp, vp, state, *newstate);
>> ++
>> ++  if (check_varstate (*newstate))
>> ++    {
>> ++      if (use)
>> ++      *((*vp)++) = use;
>> ++    }
>> ++  else if (*newstate == GRUB_PARSER_STATE_TEXT &&
>> ++         state != GRUB_PARSER_STATE_ESC && grub_isspace (use))
>> ++    {
>> ++      /*
>> ++       * Don't add more than one argument if multiple
>> ++       * spaces are used.
>> ++       */
>> ++      if (*bp != buffer && *((*bp) - 1) != '\0')
>> ++      {
>> ++        *((*bp)++) = '\0';
>> ++        (*argc)++;
>> ++      }
>> ++    }
>> ++  else if (use)
>> ++    *((*bp)++) = use;
>> ++
>> ++  return GRUB_ERR_NONE;
>> ++}
>> ++
>> + grub_err_t
>> + grub_parser_split_cmdline (const char *cmdline,
>> +                          grub_reader_getline_t getline, void *getline_data,
>> +@@ -171,35 +211,13 @@ grub_parser_split_cmdline (const char *c
>> +       for (; *rp != '\0'; rp++)
>> +       {
>> +         grub_parser_state_t newstate;
>> +-        char use;
>> +-
>> +-        newstate = grub_parser_cmdline_state (state, *rp, &use);
>> +
>> +-        /* If a variable was being processed and this character does
>> +-           not describe the variable anymore, write the variable to
>> +-           the buffer.  */
>> +-        add_var (varname, &bp, &vp, state, newstate);
>> +-
>> +-        if (check_varstate (newstate))
>> +-          {
>> +-            if (use)
>> +-              *(vp++) = use;
>> +-          }
>> +-        else
>> ++        if (process_char (*rp, buffer, &bp, varname, &vp, state, argc,
>> ++                          &newstate) != GRUB_ERR_NONE)
>> +           {
>> +-            if (newstate == GRUB_PARSER_STATE_TEXT
>> +-                && state != GRUB_PARSER_STATE_ESC && grub_isspace (use))
>> +-              {
>> +-                /* Don't add more than one argument if multiple
>> +-                   spaces are used.  */
>> +-                if (bp != buffer && *(bp - 1))
>> +-                  {
>> +-                    *(bp++) = '\0';
>> +-                    (*argc)++;
>> +-                  }
>> +-              }
>> +-            else if (use)
>> +-              *(bp++) = use;
>> ++            if (rd != cmdline)
>> ++              grub_free (rd);
>> ++            return grub_errno;
>> +           }
>> +         state = newstate;
>> +       }
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-27749_3.patch b/meta/recipes-bsp/grub/files/CVE-2020-27749_3.patch
>> new file mode 100644
>> index 0000000000..ff211a9bd4
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-27749_3.patch
>> @@ -0,0 +1,69 @@
>> +From a93ec88ea67b578c495113663a7312777de22df3 Mon Sep 17 00:00:00 2001
>> +From: Chris Coulson <chris.coulson@canonical.com>
>> +Date: Thu, 7 Jan 2021 19:53:55 +0000
>> +Subject: kern/parser: Introduce terminate_arg() helper
>> +
>> +process_char() and grub_parser_split_cmdline() use similar code for
>> +terminating the most recent argument. Add a helper function for this.
>> +
>> +Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/095-kern-parser-Introduce-terminate_arg-helper.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-27749 patch#3
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + grub-core/kern/parser.c | 23 +++++++++++++----------
>> + 1 file changed, 13 insertions(+), 10 deletions(-)
>> +
>> +Index: grub-2.04/grub-core/kern/parser.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/kern/parser.c
>> ++++ grub-2.04/grub-core/kern/parser.c
>> +@@ -129,6 +129,16 @@ add_var (char *varname, char **bp, char
>> +     *((*bp)++) = *val;
>> + }
>> +
>> ++static void
>> ++terminate_arg (char *buffer, char **bp, int *argc)
>> ++{
>> ++  if (*bp != buffer && *((*bp) - 1) != '\0')
>> ++    {
>> ++      *((*bp)++) = '\0';
>> ++      (*argc)++;
>> ++    }
>> ++}
>> ++
>> + static grub_err_t
>> + process_char (char c, char *buffer, char **bp, char *varname, char **vp,
>> +             grub_parser_state_t state, int *argc,
>> +@@ -157,11 +167,7 @@ process_char (char c, char *buffer, char
>> +        * Don't add more than one argument if multiple
>> +        * spaces are used.
>> +        */
>> +-      if (*bp != buffer && *((*bp) - 1) != '\0')
>> +-      {
>> +-        *((*bp)++) = '\0';
>> +-        (*argc)++;
>> +-      }
>> ++      terminate_arg (buffer, bp, argc);
>> +     }
>> +   else if (use)
>> +     *((*bp)++) = use;
>> +@@ -231,11 +237,8 @@ grub_parser_split_cmdline (const char *c
>> +      variable.  */
>> +   add_var (varname, &bp, &vp, state, GRUB_PARSER_STATE_TEXT);
>> +
>> +-  if (bp != buffer && *(bp - 1))
>> +-    {
>> +-      *(bp++) = '\0';
>> +-      (*argc)++;
>> +-    }
>> ++  /* Ensure that the last argument is terminated. */
>> ++  terminate_arg (buffer, &bp, argc);
>> +
>> +   /* Reserve memory for the return values.  */
>> +   args = grub_malloc (bp - buffer);
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-27749_4.patch b/meta/recipes-bsp/grub/files/CVE-2020-27749_4.patch
>> new file mode 100644
>> index 0000000000..ac18909ce9
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-27749_4.patch
>> @@ -0,0 +1,97 @@
>> +From d5d6b0d72ef3ae571720c443210b4222122cf9eb Mon Sep 17 00:00:00 2001
>> +From: Chris Coulson <chris.coulson@canonical.com>
>> +Date: Wed, 6 Jan 2021 13:54:26 +0000
>> +Subject: kern/parser: Refactor grub_parser_split_cmdline() cleanup
>> +
>> +Introduce a common function epilogue used for cleaning up on all
>> +return paths, which will simplify additional error handling to be
>> +introduced in a subsequent commit.
>> +
>> +Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/096-kern-parser-Refactor-grub_parser_split_cmdline-cleanup.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-27749 patch#4
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + grub-core/kern/parser.c | 35 ++++++++++++++++++++---------------
>> + 1 file changed, 20 insertions(+), 15 deletions(-)
>> +
>> +Index: grub-2.04/grub-core/kern/parser.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/kern/parser.c
>> ++++ grub-2.04/grub-core/kern/parser.c
>> +@@ -220,38 +220,37 @@ grub_parser_split_cmdline (const char *c
>> +
>> +         if (process_char (*rp, buffer, &bp, varname, &vp, state, argc,
>> +                           &newstate) != GRUB_ERR_NONE)
>> +-          {
>> +-            if (rd != cmdline)
>> +-              grub_free (rd);
>> +-            return grub_errno;
>> +-          }
>> ++          goto fail;
>> ++
>> +         state = newstate;
>> +       }
>> +     }
>> +   while (state != GRUB_PARSER_STATE_TEXT && !check_varstate (state));
>> +
>> +-  if (rd != cmdline)
>> +-    grub_free (rd);
>> +-
>> +   /* A special case for when the last character was part of a
>> +      variable.  */
>> +   add_var (varname, &bp, &vp, state, GRUB_PARSER_STATE_TEXT);
>> +
>> ++  /* If there are no args, then we're done. */
>> ++    if (!*argc)
>> ++    {
>> ++        grub_errno = GRUB_ERR_NONE;
>> ++        goto out;
>> ++    }
>> ++
>> +   /* Ensure that the last argument is terminated. */
>> ++
>> +   terminate_arg (buffer, &bp, argc);
>> +
>> +   /* Reserve memory for the return values.  */
>> +   args = grub_malloc (bp - buffer);
>> +   if (!args)
>> +-    return grub_errno;
>> ++    goto fail;
>> +   grub_memcpy (args, buffer, bp - buffer);
>> +
>> +   *argv = grub_calloc (*argc + 1, sizeof (char *));
>> +   if (!*argv)
>> +-    {
>> +-      grub_free (args);
>> +-      return grub_errno;
>> +-    }
>> ++    goto fail;
>> +
>> +   /* The arguments are separated with 0's, setup argv so it points to
>> +      the right values.  */
>> +@@ -264,7 +263,18 @@ grub_parser_split_cmdline (const char *c
>> +       bp++;
>> +     }
>> +
>> +-  return 0;
>> ++  grub_errno = GRUB_ERR_NONE;
>> ++
>> ++ out:
>> ++  if (rd != cmdline)
>> ++    grub_free (rd);
>> ++
>> ++  return grub_errno;
>> ++
>> ++ fail:
>> ++  grub_free (*argv);
>> ++  grub_free (args);
>> ++  goto out;
>> + }
>> +
>> + /* Helper for grub_parser_execute.  */
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-27749_5.patch b/meta/recipes-bsp/grub/files/CVE-2020-27749_5.patch
>> new file mode 100644
>> index 0000000000..e6917c606b
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-27749_5.patch
>> @@ -0,0 +1,311 @@
>> +From 4f38583d8066b81dcc04eadd2d29700f58991547 Mon Sep 17 00:00:00 2001
>> +From: Chris Coulson <chris.coulson@canonical.com>
>> +Date: Thu, 7 Jan 2021 15:15:43 +0000
>> +Subject: kern/buffer: Add variable sized heap buffer
>> +
>> +Add a new variable sized heap buffer type (grub_buffer_t) with simple
>> +operations for appending data, accessing the data and maintaining
>> +a read cursor.
>> +
>> +Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/097-kern-buffer-Add-variable-sized-heap-buffer.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-27749 patch#5
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + grub-core/Makefile.core.def |   1 +
>> + grub-core/kern/buffer.c     | 117 +++++++++++++++++++++++++++++
>> + include/grub/buffer.h       | 144 ++++++++++++++++++++++++++++++++++++
>> + 3 files changed, 262 insertions(+)
>> + create mode 100644 grub-core/kern/buffer.c
>> + create mode 100644 include/grub/buffer.h
>> +
>> +diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
>> +index e7e4d3cf5..248835aca 100644
>> +--- a/grub-core/Makefile.core.def
>> ++++ b/grub-core/Makefile.core.def
>> +@@ -123,6 +123,7 @@ kernel = {
>> +   riscv32_efi_startup = kern/riscv/efi/startup.S;
>> +   riscv64_efi_startup = kern/riscv/efi/startup.S;
>> +
>> ++  common = kern/buffer.c;
>> +   common = kern/command.c;
>> +   common = kern/corecmd.c;
>> +   common = kern/device.c;
>> +diff --git a/grub-core/kern/buffer.c b/grub-core/kern/buffer.c
>> +new file mode 100644
>> +index 000000000..9f5f8b867
>> +--- /dev/null
>> ++++ b/grub-core/kern/buffer.c
>> +@@ -0,0 +1,117 @@
>> ++/*
>> ++ *  GRUB  --  GRand Unified Bootloader
>> ++ *  Copyright (C) 2021  Free Software Foundation, Inc.
>> ++ *
>> ++ *  GRUB is free software: you can redistribute it and/or modify
>> ++ *  it under the terms of the GNU General Public License as published by
>> ++ *  the Free Software Foundation, either version 3 of the License, or
>> ++ *  (at your option) any later version.
>> ++ *
>> ++ *  GRUB is distributed in the hope that it will be useful,
>> ++ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
>> ++ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> ++ *  GNU General Public License for more details.
>> ++ *
>> ++ *  You should have received a copy of the GNU General Public License
>> ++ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
>> ++ */
>> ++
>> ++#include <grub/buffer.h>
>> ++#include <grub/err.h>
>> ++#include <grub/misc.h>
>> ++#include <grub/mm.h>
>> ++#include <grub/safemath.h>
>> ++#include <grub/types.h>
>> ++
>> ++grub_buffer_t
>> ++grub_buffer_new (grub_size_t sz)
>> ++{
>> ++  struct grub_buffer *ret;
>> ++
>> ++  ret = (struct grub_buffer *) grub_malloc (sizeof (*ret));
>> ++  if (ret == NULL)
>> ++    return NULL;
>> ++
>> ++  ret->data = (grub_uint8_t *) grub_malloc (sz);
>> ++  if (ret->data == NULL)
>> ++    {
>> ++      grub_free (ret);
>> ++      return NULL;
>> ++    }
>> ++
>> ++  ret->sz = sz;
>> ++  ret->pos = 0;
>> ++  ret->used = 0;
>> ++
>> ++  return ret;
>> ++}
>> ++
>> ++void
>> ++grub_buffer_free (grub_buffer_t buf)
>> ++{
>> ++  grub_free (buf->data);
>> ++  grub_free (buf);
>> ++}
>> ++
>> ++grub_err_t
>> ++grub_buffer_ensure_space (grub_buffer_t buf, grub_size_t req)
>> ++{
>> ++  grub_uint8_t *d;
>> ++  grub_size_t newsz = 1;
>> ++
>> ++  /* Is the current buffer size adequate? */
>> ++  if (buf->sz >= req)
>> ++    return GRUB_ERR_NONE;
>> ++
>> ++  /* Find the smallest power-of-2 size that satisfies the request. */
>> ++  while (newsz < req)
>> ++    {
>> ++      if (newsz == 0)
>> ++      return grub_error (GRUB_ERR_OUT_OF_RANGE,
>> ++                         N_("requested buffer size is too large"));
>> ++      newsz <<= 1;
>> ++    }
>> ++
>> ++  d = (grub_uint8_t *) grub_realloc (buf->data, newsz);
>> ++  if (d == NULL)
>> ++    return grub_errno;
>> ++
>> ++  buf->data = d;
>> ++  buf->sz = newsz;
>> ++
>> ++  return GRUB_ERR_NONE;
>> ++}
>> ++
>> ++void *
>> ++grub_buffer_take_data (grub_buffer_t buf)
>> ++{
>> ++  void *data = buf->data;
>> ++
>> ++  buf->data = NULL;
>> ++  buf->sz = buf->pos = buf->used = 0;
>> ++
>> ++  return data;
>> ++}
>> ++
>> ++void
>> ++grub_buffer_reset (grub_buffer_t buf)
>> ++{
>> ++  buf->pos = buf->used = 0;
>> ++}
>> ++
>> ++grub_err_t
>> ++grub_buffer_advance_read_pos (grub_buffer_t buf, grub_size_t n)
>> ++{
>> ++  grub_size_t newpos;
>> ++
>> ++  if (grub_add (buf->pos, n, &newpos))
>> ++    return grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected"));
>> ++
>> ++  if (newpos > buf->used)
>> ++    return grub_error (GRUB_ERR_OUT_OF_RANGE,
>> ++                     N_("new read is position beyond the end of the written data"));
>> ++
>> ++  buf->pos = newpos;
>> ++
>> ++  return GRUB_ERR_NONE;
>> ++}
>> +diff --git a/include/grub/buffer.h b/include/grub/buffer.h
>> +new file mode 100644
>> +index 000000000..f4b10cf28
>> +--- /dev/null
>> ++++ b/include/grub/buffer.h
>> +@@ -0,0 +1,144 @@
>> ++/*
>> ++ *  GRUB  --  GRand Unified Bootloader
>> ++ *  Copyright (C) 2021  Free Software Foundation, Inc.
>> ++ *
>> ++ *  GRUB is free software: you can redistribute it and/or modify
>> ++ *  it under the terms of the GNU General Public License as published by
>> ++ *  the Free Software Foundation, either version 3 of the License, or
>> ++ *  (at your option) any later version.
>> ++ *
>> ++ *  GRUB is distributed in the hope that it will be useful,
>> ++ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
>> ++ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> ++ *  GNU General Public License for more details.
>> ++ *
>> ++ *  You should have received a copy of the GNU General Public License
>> ++ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
>> ++ */
>> ++
>> ++#ifndef GRUB_BUFFER_H
>> ++#define GRUB_BUFFER_H 1
>> ++
>> ++#include <grub/err.h>
>> ++#include <grub/misc.h>
>> ++#include <grub/mm.h>
>> ++#include <grub/safemath.h>
>> ++#include <grub/types.h>
>> ++
>> ++struct grub_buffer
>> ++{
>> ++  grub_uint8_t *data;
>> ++  grub_size_t sz;
>> ++  grub_size_t pos;
>> ++  grub_size_t used;
>> ++};
>> ++
>> ++/*
>> ++ * grub_buffer_t represents a simple variable sized byte buffer with
>> ++ * read and write cursors. It currently only implements
>> ++ * functionality required by the only user in GRUB (append byte[s],
>> ++ * peeking data at a specified position and updating the read cursor.
>> ++ * Some things that this doesn't do yet are:
>> ++ * - Reading a portion of the buffer by copying data from the current
>> ++ *   read position in to a caller supplied destination buffer and then
>> ++ *   automatically updating the read cursor.
>> ++ * - Dropping the read part at the start of the buffer when an append
>> ++ *   requires more space.
>> ++ */
>> ++typedef struct grub_buffer *grub_buffer_t;
>> ++
>> ++/* Allocate a new buffer with the specified initial size. */
>> ++extern grub_buffer_t grub_buffer_new (grub_size_t sz);
>> ++
>> ++/* Free the buffer and its resources. */
>> ++extern void grub_buffer_free (grub_buffer_t buf);
>> ++
>> ++/* Return the number of unread bytes in this buffer. */
>> ++static inline grub_size_t
>> ++grub_buffer_get_unread_bytes (grub_buffer_t buf)
>> ++{
>> ++  return buf->used - buf->pos;
>> ++}
>> ++
>> ++/*
>> ++ * Ensure that the buffer size is at least the requested
>> ++ * number of bytes.
>> ++ */
>> ++extern grub_err_t grub_buffer_ensure_space (grub_buffer_t buf, grub_size_t req);
>> ++
>> ++/*
>> ++ * Append the specified number of bytes from the supplied
>> ++ * data to the buffer.
>> ++ */
>> ++static inline grub_err_t
>> ++grub_buffer_append_data (grub_buffer_t buf, const void *data, grub_size_t len)
>> ++{
>> ++  grub_size_t req;
>> ++
>> ++  if (grub_add (buf->used, len, &req))
>> ++    return grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected"));
>> ++
>> ++  if (grub_buffer_ensure_space (buf, req) != GRUB_ERR_NONE)
>> ++    return grub_errno;
>> ++
>> ++  grub_memcpy (&buf->data[buf->used], data, len);
>> ++  buf->used = req;
>> ++
>> ++  return GRUB_ERR_NONE;
>> ++}
>> ++
>> ++/* Append the supplied character to the buffer. */
>> ++static inline grub_err_t
>> ++grub_buffer_append_char (grub_buffer_t buf, char c)
>> ++{
>> ++  return grub_buffer_append_data (buf, &c, 1);
>> ++}
>> ++
>> ++/*
>> ++ * Forget and return the underlying data buffer. The caller
>> ++ * becomes the owner of this buffer, and must free it when it
>> ++ * is no longer required.
>> ++ */
>> ++extern void *grub_buffer_take_data (grub_buffer_t buf);
>> ++
>> ++/* Reset this buffer. Note that this does not deallocate any resources. */
>> ++void grub_buffer_reset (grub_buffer_t buf);
>> ++
>> ++/*
>> ++ * Return a pointer to the underlying data buffer at the specified
>> ++ * offset from the current read position. Note that this pointer may
>> ++ * become invalid if the buffer is mutated further.
>> ++ */
>> ++static inline void *
>> ++grub_buffer_peek_data_at (grub_buffer_t buf, grub_size_t off)
>> ++{
>> ++  if (grub_add (buf->pos, off, &off))
>> ++    {
>> ++      grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected."));
>> ++      return NULL;
>> ++    }
>> ++
>> ++  if (off >= buf->used)
>> ++    {
>> ++      grub_error (GRUB_ERR_OUT_OF_RANGE, N_("peek out of range"));
>> ++      return NULL;
>> ++    }
>> ++
>> ++  return &buf->data[off];
>> ++}
>> ++
>> ++/*
>> ++ * Return a pointer to the underlying data buffer at the current
>> ++ * read position. Note that this pointer may become invalid if the
>> ++ * buffer is mutated further.
>> ++ */
>> ++static inline void *
>> ++grub_buffer_peek_data (grub_buffer_t buf)
>> ++{
>> ++  return grub_buffer_peek_data_at (buf, 0);
>> ++}
>> ++
>> ++/* Advance the read position by the specified number of bytes. */
>> ++extern grub_err_t grub_buffer_advance_read_pos (grub_buffer_t buf, grub_size_t n);
>> ++
>> ++#endif /* GRUB_BUFFER_H */
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-27749_6.patch b/meta/recipes-bsp/grub/files/CVE-2020-27749_6.patch
>> new file mode 100644
>> index 0000000000..8e21c948ce
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-27749_6.patch
>> @@ -0,0 +1,254 @@
>> +From e44c6dbbb5c344aaca6bf20967f3b2a2f9a25eba Mon Sep 17 00:00:00 2001
>> +From: Chris Coulson <chris.coulson@canonical.com>
>> +Date: Thu, 7 Jan 2021 19:21:03 +0000
>> +Subject: kern/parser: Fix a stack buffer overflow
>> +
>> +grub_parser_split_cmdline() expands variable names present in the supplied
>> +command line in to their corresponding variable contents and uses a 1 kiB
>> +stack buffer for temporary storage without sufficient bounds checking. If
>> +the function is called with a command line that references a variable with
>> +a sufficiently large payload, it is possible to overflow the stack
>> +buffer via tab completion, corrupt the stack frame and potentially
>> +control execution.
>> +
>> +Fixes: CVE-2020-27749
>> +
>> +Reported-by: Chris Coulson <chris.coulson@canonical.com>
>> +Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
>> +Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/098-kern-parser-Fix-a-stack-buffer-overflow.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-27749 patch#6
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + grub-core/kern/parser.c | 110 ++++++++++++++++++++++++----------------
>> + 1 file changed, 67 insertions(+), 43 deletions(-)
>> +
>> +Index: grub-2.04/grub-core/kern/parser.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/kern/parser.c
>> ++++ grub-2.04/grub-core/kern/parser.c
>> +@@ -18,6 +18,7 @@
>> +  */
>> +
>> + #include <grub/parser.h>
>> ++#include <grub/buffer.h>
>> + #include <grub/env.h>
>> + #include <grub/misc.h>
>> + #include <grub/mm.h>
>> +@@ -107,8 +108,8 @@ check_varstate (grub_parser_state_t s)
>> + }
>> +
>> +
>> +-static void
>> +-add_var (char *varname, char **bp, char **vp,
>> ++static grub_err_t
>> ++add_var (grub_buffer_t varname, grub_buffer_t buf,
>> +        grub_parser_state_t state, grub_parser_state_t newstate)
>> + {
>> +   const char *val;
>> +@@ -116,31 +117,41 @@ add_var (char *varname, char **bp, char
>> +   /* Check if a variable was being read in and the end of the name
>> +      was reached.  */
>> +   if (!(check_varstate (state) && !check_varstate (newstate)))
>> +-    return;
>> ++    return GRUB_ERR_NONE;
>> ++
>> ++  if (grub_buffer_append_char (varname, '\0') != GRUB_ERR_NONE)
>> ++    return grub_errno;
>> +
>> +-  *((*vp)++) = '\0';
>> +-  val = grub_env_get (varname);
>> +-  *vp = varname;
>> ++  val = grub_env_get ((const char *) grub_buffer_peek_data (varname));
>> ++  grub_buffer_reset (varname);
>> +   if (!val)
>> +-    return;
>> ++    return GRUB_ERR_NONE;
>> +
>> +   /* Insert the contents of the variable in the buffer.  */
>> +-  for (; *val; val++)
>> +-    *((*bp)++) = *val;
>> ++  return grub_buffer_append_data (buf, val, grub_strlen (val));
>> + }
>> +
>> +-static void
>> +-terminate_arg (char *buffer, char **bp, int *argc)
>> ++static grub_err_t
>> ++terminate_arg (grub_buffer_t buffer, int *argc)
>> + {
>> +-  if (*bp != buffer && *((*bp) - 1) != '\0')
>> +-    {
>> +-      *((*bp)++) = '\0';
>> +-      (*argc)++;
>> +-    }
>> ++  grub_size_t unread = grub_buffer_get_unread_bytes (buffer);
>> ++
>> ++  if (unread == 0)
>> ++    return GRUB_ERR_NONE;
>> ++
>> ++  if (*(const char *) grub_buffer_peek_data_at (buffer, unread - 1) == '\0')
>> ++    return GRUB_ERR_NONE;
>> ++
>> ++  if (grub_buffer_append_char (buffer, '\0') != GRUB_ERR_NONE)
>> ++    return grub_errno;
>> ++
>> ++  (*argc)++;
>> ++
>> ++  return GRUB_ERR_NONE;
>> + }
>> +
>> + static grub_err_t
>> +-process_char (char c, char *buffer, char **bp, char *varname, char **vp,
>> ++process_char (char c, grub_buffer_t buffer, grub_buffer_t varname,
>> +             grub_parser_state_t state, int *argc,
>> +             grub_parser_state_t *newstate)
>> + {
>> +@@ -153,12 +164,13 @@ process_char (char c, char *buffer, char
>> +    * not describe the variable anymore, write the variable to
>> +    * the buffer.
>> +    */
>> +-  add_var (varname, bp, vp, state, *newstate);
>> ++  if (add_var (varname, buffer, state, *newstate) != GRUB_ERR_NONE)
>> ++    return grub_errno;
>> +
>> +   if (check_varstate (*newstate))
>> +     {
>> +       if (use)
>> +-      *((*vp)++) = use;
>> ++        return grub_buffer_append_char (varname, use);
>> +     }
>> +   else if (*newstate == GRUB_PARSER_STATE_TEXT &&
>> +          state != GRUB_PARSER_STATE_ESC && grub_isspace (use))
>> +@@ -167,10 +179,10 @@ process_char (char c, char *buffer, char
>> +        * Don't add more than one argument if multiple
>> +        * spaces are used.
>> +        */
>> +-      terminate_arg (buffer, bp, argc);
>> ++      return terminate_arg (buffer, argc);
>> +     }
>> +   else if (use)
>> +-    *((*bp)++) = use;
>> ++    return grub_buffer_append_char (buffer, use);
>> +
>> +   return GRUB_ERR_NONE;
>> + }
>> +@@ -181,18 +193,21 @@ grub_parser_split_cmdline (const char *c
>> +                          int *argc, char ***argv)
>> + {
>> +   grub_parser_state_t state = GRUB_PARSER_STATE_TEXT;
>> +-  /* XXX: Fixed size buffer, perhaps this buffer should be dynamically
>> +-     allocated.  */
>> +-  char buffer[1024];
>> +-  char *bp = buffer;
>> ++  grub_buffer_t buffer, varname;
>> +   char *rd = (char *) cmdline;
>> +   char *rp = rd;
>> +-  char varname[200];
>> +-  char *vp = varname;
>> +-  char *args;
>> +   int i;
>> +
>> +   *argc = 0;
>> ++
>> ++  buffer = grub_buffer_new (1024);
>> ++  if (buffer == NULL)
>> ++    return grub_errno;
>> ++
>> ++  varname = grub_buffer_new (200);
>> ++  if (varname == NULL)
>> ++    goto fail;
>> ++
>> +   do
>> +     {
>> +       if (rp == NULL || *rp == '\0')
>> +@@ -218,7 +233,7 @@ grub_parser_split_cmdline (const char *c
>> +       {
>> +         grub_parser_state_t newstate;
>> +
>> +-        if (process_char (*rp, buffer, &bp, varname, &vp, state, argc,
>> ++        if (process_char (*rp, buffer, varname, state, argc,
>> +                           &newstate) != GRUB_ERR_NONE)
>> +           goto fail;
>> +
>> +@@ -229,7 +244,13 @@ grub_parser_split_cmdline (const char *c
>> +
>> +   /* A special case for when the last character was part of a
>> +      variable.  */
>> +-  add_var (varname, &bp, &vp, state, GRUB_PARSER_STATE_TEXT);
>> ++   if (add_var (varname, buffer, state, GRUB_PARSER_STATE_TEXT) != GRUB_ERR_NONE)
>> ++      goto fail;
>> ++
>> ++  /* Ensure that the last argument is terminated. */
>> ++
>> ++  if (terminate_arg (buffer, argc) != GRUB_ERR_NONE)
>> ++     goto fail;
>> +
>> +   /* If there are no args, then we're done. */
>> +     if (!*argc)
>> +@@ -238,15 +259,6 @@ grub_parser_split_cmdline (const char *c
>> +         goto out;
>> +     }
>> +
>> +-  /* Ensure that the last argument is terminated. */
>> +-
>> +-  terminate_arg (buffer, &bp, argc);
>> +-
>> +-  /* Reserve memory for the return values.  */
>> +-  args = grub_malloc (bp - buffer);
>> +-  if (!args)
>> +-    goto fail;
>> +-  grub_memcpy (args, buffer, bp - buffer);
>> +
>> +   *argv = grub_calloc (*argc + 1, sizeof (char *));
>> +   if (!*argv)
>> +@@ -254,26 +266,39 @@ grub_parser_split_cmdline (const char *c
>> +
>> +   /* The arguments are separated with 0's, setup argv so it points to
>> +      the right values.  */
>> +-  bp = args;
>> +   for (i = 0; i < *argc; i++)
>> +     {
>> +-      (*argv)[i] = bp;
>> +-      while (*bp)
>> +-      bp++;
>> +-      bp++;
>> ++      char *arg;
>> ++
>> ++      if (i > 0)
>> ++      {
>> ++        if (grub_buffer_advance_read_pos (buffer, 1) != GRUB_ERR_NONE)
>> ++          goto fail;
>> ++      }
>> ++
>> ++      arg = (char *) grub_buffer_peek_data (buffer);
>> ++      if (arg == NULL ||
>> ++        grub_buffer_advance_read_pos (buffer, grub_strlen (arg)) != GRUB_ERR_NONE)
>> ++      goto fail;
>> ++
>> ++      (*argv)[i] = arg;
>> +     }
>> +
>> ++  /* Keep memory for the return values. */
>> ++  grub_buffer_take_data (buffer);
>> ++
>> +   grub_errno = GRUB_ERR_NONE;
>> +
>> +  out:
>> +   if (rd != cmdline)
>> +     grub_free (rd);
>> ++  grub_buffer_free (buffer);
>> ++  grub_buffer_free (varname);
>> +
>> +   return grub_errno;
>> +
>> +  fail:
>> +   grub_free (*argv);
>> +-  grub_free (args);
>> +   goto out;
>> + }
>> +
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2020-27779.patch b/meta/recipes-bsp/grub/files/CVE-2020-27779.patch
>> new file mode 100644
>> index 0000000000..cf489a5468
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2020-27779.patch
>> @@ -0,0 +1,72 @@
>> +From 4ad34d7d0aff5467cc2a2b3e0c55750856c19545 Mon Sep 17 00:00:00 2001
>> +From: Javier Martinez Canillas <javierm@redhat.com>
>> +Date: Wed, 14 Oct 2020 16:33:42 +0200
>> +Subject: mmap: Don't register cutmem and badram commands when lockdown is
>> + enforced
>> +
>> +The cutmem and badram commands can be used to remove EFI memory regions
>> +and potentially disable the UEFI Secure Boot. Prevent the commands to be
>> +registered if the GRUB is locked down.
>> +
>> +Fixes: CVE-2020-27779
>> +
>> +Reported-by: Teddy Reed <teddy.reed@gmail.com>
>> +Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/007-mmap-Don-t-register-cutmem-and-badram-commands-when-lockdown-is-enforced.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2020-27779
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +---
>> + docs/grub.texi        |  4 ++++
>> + grub-core/mmap/mmap.c | 13 +++++++------
>> + 2 files changed, 11 insertions(+), 6 deletions(-)
>> +
>> +Index: grub-2.04/docs/grub.texi
>> +===================================================================
>> +--- grub-2.04.orig/docs/grub.texi
>> ++++ grub-2.04/docs/grub.texi
>> +@@ -4051,6 +4051,10 @@ this page is to be filtered.  This synta
>> + that are often result of memory damage, due to physical distribution of memory
>> + cells.
>> +
>> ++Note: The command is not allowed when lockdown is enforced (@pxref{Lockdown}).
>> ++      This prevents removing EFI memory regions to potentially subvert the
>> ++      security mechanisms provided by the UEFI secure boot.
>> ++
>> + @node blocklist
>> + @subsection blocklist
>> +
>> +Index: grub-2.04/grub-core/mmap/mmap.c
>> +===================================================================
>> +--- grub-2.04.orig/grub-core/mmap/mmap.c
>> ++++ grub-2.04/grub-core/mmap/mmap.c
>> +@@ -20,6 +20,7 @@
>> + #include <grub/memory.h>
>> + #include <grub/machine/memory.h>
>> + #include <grub/err.h>
>> ++#include <grub/lockdown.h>
>> + #include <grub/misc.h>
>> + #include <grub/mm.h>
>> + #include <grub/command.h>
>> +@@ -534,12 +535,12 @@ static grub_command_t cmd, cmd_cut;
>> +
>> + GRUB_MOD_INIT(mmap)
>> + {
>> +-  cmd = grub_register_command ("badram", grub_cmd_badram,
>> +-                             N_("ADDR1,MASK1[,ADDR2,MASK2[,...]]"),
>> +-                             N_("Declare memory regions as faulty (badram)."));
>> +-  cmd_cut = grub_register_command ("cutmem", grub_cmd_cutmem,
>> +-                                 N_("FROM[K|M|G] TO[K|M|G]"),
>> +-                                 N_("Remove any memory regions in specified range."));
>> ++  cmd = grub_register_command_lockdown ("badram", grub_cmd_badram,
>> ++                                        N_("ADDR1,MASK1[,ADDR2,MASK2[,...]]"),
>> ++                                        N_("Declare memory regions as faulty (badram)."));
>> ++  cmd_cut = grub_register_command_lockdown ("cutmem", grub_cmd_cutmem,
>> ++                                            N_("FROM[K|M|G] TO[K|M|G]"),
>> ++                                            N_("Remove any memory regions in specified range."));
>> +
>> + }
>> +
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2021-20225.patch b/meta/recipes-bsp/grub/files/CVE-2021-20225.patch
>> new file mode 100644
>> index 0000000000..e7b213868e
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2021-20225.patch
>> @@ -0,0 +1,57 @@
>> +From e46927de3e5bac21bc91986099c6b7ae014a4016 Mon Sep 17 00:00:00 2001
>> +From: Daniel Axtens <dja@axtens.net>
>> +Date: Fri, 22 Jan 2021 16:07:29 +1100
>> +Subject: lib/arg: Block repeated short options that require an argument
>> +
>> +Fuzzing found the following crash:
>> +
>> +  search -hhhhhhhhhhhhhf
>> +
>> +We didn't allocate enough option space for 13 hints because the
>> +allocation code counts the number of discrete arguments (i.e. argc).
>> +However, the shortopt parsing code will happily keep processing
>> +a combination of short options without checking if those short
>> +options require an argument. This means you can easily end writing
>> +past the allocated option space.
>> +
>> +This fixes a OOB write which can cause heap corruption.
>> +
>> +Fixes: CVE-2021-20225
>> +
>> +Signed-off-by: Daniel Axtens <dja@axtens.net>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/061-lib-arg-Block-repeated-short-options-that-require-an-argument.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2021-20225
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + grub-core/lib/arg.c | 13 +++++++++++++
>> + 1 file changed, 13 insertions(+)
>> +
>> +diff --git a/grub-core/lib/arg.c b/grub-core/lib/arg.c
>> +index 3288609a5..537c5e94b 100644
>> +--- a/grub-core/lib/arg.c
>> ++++ b/grub-core/lib/arg.c
>> +@@ -299,6 +299,19 @@ grub_arg_parse (grub_extcmd_t cmd, int argc, char **argv,
>> +                it can have an argument value.  */
>> +             if (*curshort)
>> +               {
>> ++                /*
>> ++                 * Only permit further short opts if this one doesn't
>> ++                 * require a value.
>> ++                 */
>> ++                if (opt->type != ARG_TYPE_NONE &&
>> ++                    !(opt->flags & GRUB_ARG_OPTION_OPTIONAL))
>> ++                  {
>> ++                    grub_error (GRUB_ERR_BAD_ARGUMENT,
>> ++                                N_("missing mandatory option for `%s'"),
>> ++                                opt->longarg);
>> ++                    goto fail;
>> ++                  }
>> ++
>> +                 if (parse_option (cmd, opt, 0, usr) || grub_errno)
>> +                   goto fail;
>> +               }
>> diff --git a/meta/recipes-bsp/grub/files/CVE-2021-20233.patch b/meta/recipes-bsp/grub/files/CVE-2021-20233.patch
>> new file mode 100644
>> index 0000000000..3f0abe0bde
>> --- /dev/null
>> +++ b/meta/recipes-bsp/grub/files/CVE-2021-20233.patch
>> @@ -0,0 +1,50 @@
>> +From e8813743f74b8ac23bf40ed9ee86b759d0475666 Mon Sep 17 00:00:00 2001
>> +From: Daniel Axtens <dja@axtens.net>
>> +Date: Fri, 22 Jan 2021 17:10:48 +1100
>> +Subject: commands/menuentry: Fix quoting in setparams_prefix()
>> +
>> +Commit 9acdcbf32542 (use single quotes in menuentry setparams command)
>> +says that expressing a quoted single quote will require 3 characters. It
>> +actually requires (and always did require!) 4 characters:
>> +
>> +  str: a'b => a'\''b
>> +  len:  3  => 6 (2 for the letters + 4 for the quote)
>> +
>> +This leads to not allocating enough memory and thus out of bounds writes
>> +that have been observed to cause heap corruption.
>> +
>> +Allocate 4 bytes for each single quote.
>> +
>> +Commit 22e7dbb2bb81 (Fix quoting in legacy parser.) does the same
>> +quoting, but it adds 3 as extra overhead on top of the single byte that
>> +the quote already needs. So it's correct.
>> +
>> +Fixes: CVE-2021-20233
>> +Fixes: 9acdcbf32542 (use single quotes in menuentry setparams command)
>> +
>> +Signed-off-by: Daniel Axtens <dja@axtens.net>
>> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> +
>> +Patch-Name: 2021-02-security/063-commands-menuentry-Fix-quoting-in-setparams_prefix.patch
>> +
>> +Upstream-Status: Backport
>> +CVE: CVE-2021-20233
>> +Signed-off-by: Armin Kuster <akuster@mvista.com>
>> +
>> +---
>> + grub-core/commands/menuentry.c | 2 +-
>> + 1 file changed, 1 insertion(+), 1 deletion(-)
>> +
>> +diff --git a/grub-core/commands/menuentry.c b/grub-core/commands/menuentry.c
>> +index 9164df744..720e6d8ea 100644
>> +--- a/grub-core/commands/menuentry.c
>> ++++ b/grub-core/commands/menuentry.c
>> +@@ -230,7 +230,7 @@ setparams_prefix (int argc, char **args)
>> +       len += 3; /* 3 = 1 space + 2 quotes */
>> +       p = args[i];
>> +       while (*p)
>> +-      len += (*p++ == '\'' ? 3 : 1);
>> ++      len += (*p++ == '\'' ? 4 : 1);
>> +     }
>> +
>> +   result = grub_malloc (len + 2);
>> diff --git a/meta/recipes-bsp/grub/grub2.inc b/meta/recipes-bsp/grub/grub2.inc
>> index 180e3752f8..d8c4337cf3 100644
>> --- a/meta/recipes-bsp/grub/grub2.inc
>> +++ b/meta/recipes-bsp/grub/grub2.inc
>> @@ -31,6 +31,22 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \
>>             file://CVE-2020-15706-script-Avoid-a-use-after-free-when-redefining-a-func.patch \
>>             file://CVE-2020-15707-linux-Fix-integer-overflows-in-initrd-size-handling.patch \
>>             file://determinism.patch \
>> +           file://CVE-2020-25632.patch \
>> +           file://CVE-2020-25647.patch \
>> +           file://CVE-2020-14372_p1.patch \
>> +           file://CVE-2020-14372_p2.patch \
>> +           file://CVE-2020-14372_p3.patch \
>> +           file://CVE-2020-14372_p4.patch \
>> +           file://CVE-2020-14372.patch \
>> +           file://CVE-2020-27779.patch \
>> +           file://CVE-2021-20225.patch \
>> +           file://CVE-2021-20233.patch \
>> +           file://CVE-2020-27749_1.patch \
>> +           file://CVE-2020-27749_2.patch \
>> +           file://CVE-2020-27749_3.patch \
>> +           file://CVE-2020-27749_4.patch \
>> +           file://CVE-2020-27749_5.patch \
>> +           file://CVE-2020-27749_6.patch \
>>  "
>>  SRC_URI[md5sum] = "5ce674ca6b2612d8939b9e6abed32934"
>>  SRC_URI[sha256sum] = "f10c85ae3e204dbaec39ae22fa3c5e99f0665417e91c2cb49b7e5031658ba6ea"
>> --
>> 2.25.1
>>
>>
>> 
>>


      reply	other threads:[~2021-09-06 23:58 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-05 22:58 [dunfell][PATCH 1/2] gdk-pixbuf: fix CVE-2021-20240 Armin Kuster
2021-09-05 22:58 ` [dunfell][PATCH 2/2] grub2: Several cve fixes Armin Kuster
2021-09-06 17:28   ` [OE-core] " Steve Sakoman
2021-09-06 23:58     ` Armin Kuster [this message]

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