Both syscalls (kexec and kexec_file) do the same check, lets factor it
out.

Signed-off-by: Ricardo Ribalda <riba...@chromium.org>
---
 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(-)

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 41a686996aaa..e9e1ab5e8006 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -406,7 +406,8 @@ 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_permited(void);
 
 #ifndef kexec_flush_icache_page
 #define kexec_flush_icache_page(page)
diff --git a/kernel/kexec.c b/kernel/kexec.c
index cb8e6e6f983c..d83fc9093aff 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_permited())
                return -EPERM;
 
        /* Permit LSMs and IMA to fail the kexec */
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index ca2743f9c634..18bd90ca9c99 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -928,7 +928,7 @@ 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[] = {
        {
@@ -952,6 +952,15 @@ static int __init kexec_core_sysctl_init(void)
 late_initcall(kexec_core_sysctl_init);
 #endif
 
+bool kexec_load_permited(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 45637511e0de..701147c118d4 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_permited())
                return -EPERM;
 
        /* Make sure we have a legal set of flags */

-- 
2.39.0.rc0.267.gcb52ba06e7-goog-b4-0.11.0-dev-696ae

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

Reply via email to