The patch titled
Subject: kexec: factor out kexec_load_permitted
has been added to the -mm mm-nonmm-unstable branch. Its filename is
kexec-factor-out-kexec_load_permitted.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kexec-factor-out-kexec_load_permitted.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
Subject: kexec: factor out kexec_load_permitted
Date: Wed, 04 Jan 2023 15:38:47 +0100
Both syscalls (kexec and kexec_file) do the same check, let's factor it
out.
Link: https://lkml.kernel.org/r/20221114-disable-kexec-reset-v6-2-6a8531a09b9a@xxxxxxxxxxxx
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
Reviewed-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Acked-by: Baoquan He <bhe@xxxxxxxxxx>
Cc: Bagas Sanjaya <bagasdotme@xxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx>
Cc: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Philipp Rudo <prudo@xxxxxxxxxx>
Cc: Ross Zwisler <zwisler@xxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/kexec.h | 3 ++-
kernel/kexec.c | 2 +-
kernel/kexec_core.c | 11 ++++++++++-
kernel/kexec_file.c | 2 +-
4 files changed, 14 insertions(+), 4 deletions(-)
--- a/include/linux/kexec.h~kexec-factor-out-kexec_load_permitted
+++ a/include/linux/kexec.h
@@ -403,7 +403,8 @@ extern int kimage_crash_copy_vmcoreinfo(
extern struct kimage *kexec_image;
extern struct kimage *kexec_crash_image;
-extern int kexec_load_disabled;
+
+bool kexec_load_permitted(void);
#ifndef kexec_flush_icache_page
#define kexec_flush_icache_page(page)
--- a/kernel/kexec.c~kexec-factor-out-kexec_load_permitted
+++ a/kernel/kexec.c
@@ -193,7 +193,7 @@ static inline int kexec_load_check(unsig
int result;
/* We only trust the superuser with rebooting the system. */
- if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
+ if (!kexec_load_permitted())
return -EPERM;
/* Permit LSMs and IMA to fail the kexec */
--- a/kernel/kexec_core.c~kexec-factor-out-kexec_load_permitted
+++ a/kernel/kexec_core.c
@@ -922,7 +922,7 @@ int kimage_load_segment(struct kimage *i
struct kimage *kexec_image;
struct kimage *kexec_crash_image;
-int kexec_load_disabled;
+static int kexec_load_disabled;
#ifdef CONFIG_SYSCTL
static struct ctl_table kexec_core_sysctls[] = {
{
@@ -946,6 +946,15 @@ static int __init kexec_core_sysctl_init
late_initcall(kexec_core_sysctl_init);
#endif
+bool kexec_load_permitted(void)
+{
+ /*
+ * Only the superuser can use the kexec syscall and if it has not
+ * been disabled.
+ */
+ return capable(CAP_SYS_BOOT) && !kexec_load_disabled;
+}
+
/*
* No panic_cpu check version of crash_kexec(). This function is called
* only when panic_cpu holds the current CPU number; this is the only CPU
--- a/kernel/kexec_file.c~kexec-factor-out-kexec_load_permitted
+++ a/kernel/kexec_file.c
@@ -330,7 +330,7 @@ SYSCALL_DEFINE5(kexec_file_load, int, ke
struct kimage **dest_image, *image;
/* We only trust the superuser with rebooting the system. */
- if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
+ if (!kexec_load_permitted())
return -EPERM;
/* Make sure we have a legal set of flags */
_
Patches currently in -mm which might be from ribalda@xxxxxxxxxxxx are
scripts-spellingtxt-add-permitted.patch
kvm-x86-fix-trivial-typo.patch
documentation-sysctl-correct-kexec_load_disabled.patch
kexec-factor-out-kexec_load_permitted.patch
kexec-introduce-sysctl-parameters-kexec_load_limit_.patch
