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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
commit08b74a000942a380fe028845f92cd3a0dee827d5 (patch)
treeaa78b4e12607c3e1fcce8d5cc42df4330792f118 /debian/patches/features/all/lockdown/0001-Add-the-ability-to-lock-down-access-to-the-running-k.patch
parentAdding upstream version 4.19.249. (diff)
downloadlinux-debian/4.19.249-2.tar.xz
linux-debian/4.19.249-2.zip
Adding debian version 4.19.249-2.debian/4.19.249-2debian
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'debian/patches/features/all/lockdown/0001-Add-the-ability-to-lock-down-access-to-the-running-k.patch')
-rw-r--r--debian/patches/features/all/lockdown/0001-Add-the-ability-to-lock-down-access-to-the-running-k.patch164
1 files changed, 164 insertions, 0 deletions
diff --git a/debian/patches/features/all/lockdown/0001-Add-the-ability-to-lock-down-access-to-the-running-k.patch b/debian/patches/features/all/lockdown/0001-Add-the-ability-to-lock-down-access-to-the-running-k.patch
new file mode 100644
index 000000000..9a8cd7c82
--- /dev/null
+++ b/debian/patches/features/all/lockdown/0001-Add-the-ability-to-lock-down-access-to-the-running-k.patch
@@ -0,0 +1,164 @@
+From: David Howells <dhowells@redhat.com>
+Date: Wed, 8 Nov 2017 15:11:31 +0000
+Subject: [01/29] Add the ability to lock down access to the running kernel
+ image
+Origin: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit?id=6d350e2534bfaaaa3e523484b2ca44d22377e951
+
+Provide a single call to allow kernel code to determine whether the system
+should be locked down, thereby disallowing various accesses that might
+allow the running kernel image to be changed including the loading of
+modules that aren't validly signed with a key we recognise, fiddling with
+MSR registers and disallowing hibernation,
+
+Signed-off-by: David Howells <dhowells@redhat.com>
+Acked-by: James Morris <james.l.morris@oracle.com>
+---
+ include/linux/kernel.h | 17 ++++++++++++++
+ include/linux/security.h | 8 +++++++
+ security/Kconfig | 8 +++++++
+ security/Makefile | 3 +++
+ security/lock_down.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++
+ 5 files changed, 96 insertions(+)
+ create mode 100644 security/lock_down.c
+
+Index: linux/include/linux/kernel.h
+===================================================================
+--- linux.orig/include/linux/kernel.h
++++ linux/include/linux/kernel.h
+@@ -341,6 +341,23 @@ static inline void refcount_error_report
+ { }
+ #endif
+
++#ifdef CONFIG_LOCK_DOWN_KERNEL
++extern bool __kernel_is_locked_down(const char *what, bool first);
++#else
++static inline bool __kernel_is_locked_down(const char *what, bool first)
++{
++ return false;
++}
++#endif
++
++#define kernel_is_locked_down(what) \
++ ({ \
++ static bool message_given; \
++ bool locked_down = __kernel_is_locked_down(what, !message_given); \
++ message_given = true; \
++ locked_down; \
++ })
++
+ /* Internal, do not use. */
+ int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
+ int __must_check _kstrtol(const char *s, unsigned int base, long *res);
+Index: linux/include/linux/security.h
+===================================================================
+--- linux.orig/include/linux/security.h
++++ linux/include/linux/security.h
+@@ -1843,5 +1843,13 @@ static inline void free_secdata(void *se
+ { }
+ #endif /* CONFIG_SECURITY */
+
++#ifdef CONFIG_LOCK_DOWN_KERNEL
++extern void __init init_lockdown(void);
++#else
++static inline void __init init_lockdown(void)
++{
++}
++#endif
++
+ #endif /* ! __LINUX_SECURITY_H */
+
+Index: linux/security/Kconfig
+===================================================================
+--- linux.orig/security/Kconfig
++++ linux/security/Kconfig
+@@ -239,6 +239,14 @@ config STATIC_USERMODEHELPER_PATH
+ If you wish for all usermode helper programs to be disabled,
+ specify an empty string here (i.e. "").
+
++config LOCK_DOWN_KERNEL
++ bool "Allow the kernel to be 'locked down'"
++ help
++ Allow the kernel to be locked down under certain circumstances, for
++ instance if UEFI secure boot is enabled. Locking down the kernel
++ turns off various features that might otherwise allow access to the
++ kernel image (eg. setting MSR registers).
++
+ source security/selinux/Kconfig
+ source security/smack/Kconfig
+ source security/tomoyo/Kconfig
+Index: linux/security/Makefile
+===================================================================
+--- linux.orig/security/Makefile
++++ linux/security/Makefile
+@@ -30,3 +30,6 @@ obj-$(CONFIG_CGROUP_DEVICE) += device_c
+ # Object integrity file lists
+ subdir-$(CONFIG_INTEGRITY) += integrity
+ obj-$(CONFIG_INTEGRITY) += integrity/
++
++# Allow the kernel to be locked down
++obj-$(CONFIG_LOCK_DOWN_KERNEL) += lock_down.o
+Index: linux/security/lock_down.c
+===================================================================
+--- /dev/null
++++ linux/security/lock_down.c
+@@ -0,0 +1,60 @@
++/* Lock down the kernel
++ *
++ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
++ * Written by David Howells (dhowells@redhat.com)
++ *
++ * This program is free software; you can redistribute it and/or
++ * modify it under the terms of the GNU General Public Licence
++ * as published by the Free Software Foundation; either version
++ * 2 of the Licence, or (at your option) any later version.
++ */
++
++#include <linux/security.h>
++#include <linux/export.h>
++
++static __ro_after_init bool kernel_locked_down;
++
++/*
++ * Put the kernel into lock-down mode.
++ */
++static void __init lock_kernel_down(const char *where)
++{
++ if (!kernel_locked_down) {
++ kernel_locked_down = true;
++ pr_notice("Kernel is locked down from %s; see man kernel_lockdown.7\n",
++ where);
++ }
++}
++
++static int __init lockdown_param(char *ignored)
++{
++ lock_kernel_down("command line");
++ return 0;
++}
++
++early_param("lockdown", lockdown_param);
++
++/*
++ * Lock the kernel down from very early in the arch setup. This must happen
++ * prior to things like ACPI being initialised.
++ */
++void __init init_lockdown(void)
++{
++#ifdef CONFIG_LOCK_DOWN_IN_EFI_SECURE_BOOT
++ if (efi_enabled(EFI_SECURE_BOOT))
++ lock_kernel_down("EFI secure boot");
++#endif
++}
++
++/**
++ * kernel_is_locked_down - Find out if the kernel is locked down
++ * @what: Tag to use in notice generated if lockdown is in effect
++ */
++bool __kernel_is_locked_down(const char *what, bool first)
++{
++ if (what && first && kernel_locked_down)
++ pr_notice("Lockdown: %s is restricted; see man kernel_lockdown.7\n",
++ what);
++ return kernel_locked_down;
++}
++EXPORT_SYMBOL(__kernel_is_locked_down);