diff options
| author | Ricardo Ribalda <ribalda@chromium.org> | 2023-01-04 15:38:47 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-02-02 22:50:04 -0800 |
| commit | 7e99f8b69c11c104933b9bc8fda226ebfb8aaaa5 (patch) | |
| tree | f6d0c0a96b7af09eea2f86d5d7bd1bb42f2ec7b9 | |
| parent | 06dcb0138f5f815f50142234b2e06f5540471715 (diff) | |
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>
| -rw-r--r-- | include/linux/kexec.h | 3 | ||||
| -rw-r--r-- | kernel/kexec.c | 2 | ||||
| -rw-r--r-- | kernel/kexec_core.c | 11 | ||||
| -rw-r--r-- | kernel/kexec_file.c | 2 |
4 files changed, 14 insertions, 4 deletions
diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 5dd4343c1bbe..f18a3c9e813b 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -403,7 +403,8 @@ extern int kimage_crash_copy_vmcoreinfo(struct kimage *image); 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) 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 */ |