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authorRicardo Ribalda <ribalda@chromium.org>2023-01-04 15:38:47 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-02-03 07:50:04 +0100
commit7e99f8b69c11c104933b9bc8fda226ebfb8aaaa5 (patch)
treef6d0c0a96b7af09eea2f86d5d7bd1bb42f2ec7b9 /kernel
parentDocumentation: sysctl: correct kexec_load_disabled (diff)
downloadlinux-7e99f8b69c11c104933b9bc8fda226ebfb8aaaa5.tar.xz
linux-7e99f8b69c11c104933b9bc8fda226ebfb8aaaa5.zip
kexec: factor out kexec_load_permitted
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@chromium.org Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Baoquan He <bhe@redhat.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Guilherme G. Piccoli <gpiccoli@igalia.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Philipp Rudo <prudo@redhat.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kexec.c2
-rw-r--r--kernel/kexec_core.c11
-rw-r--r--kernel/kexec_file.c2
3 files changed, 12 insertions, 3 deletions
diff --git a/kernel/kexec.c b/kernel/kexec.c
index cb8e6e6f983c..ce1bca874a8d 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -193,7 +193,7 @@ static inline int kexec_load_check(unsigned long nr_segments,
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 */
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 969e8f52f7da..d51ebbaeb1b2 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -922,7 +922,7 @@ int kimage_load_segment(struct kimage *image,
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(void)
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
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index dd5983010b7b..c897eb4b8c8c 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -330,7 +330,7 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
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 */