[PATCH 4.14 079/135] x86/kexec: Dont setup EFI info if EFI runtime is not enabled

[Greg Kroah-Hartman <gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 2aa958c99c7fd3162b089a1a56a34a0cdb778de1 ]

Kexec-ing a kernel with "efi=noruntime" on the first kernel's command
line causes the following null pointer dereference:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
  #PF error: [normal kernel read fault]
  Call Trace:
   efi_runtime_map_copy+0x28/0x30
   bzImage64_load+0x688/0x872
   arch_kexec_kernel_image_load+0x6d/0x70
   kimage_file_alloc_init+0x13e/0x220
   __x64_sys_kexec_file_load+0x144/0x290
   do_syscall_64+0x55/0x1a0
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

Just skip the EFI info setup if EFI runtime services are not enabled.

 [ bp: Massage commit message. ]

Suggested-by: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Kairui Song <kasong-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Borislav Petkov <bp-l3A5Bk7waGM@public.gmane.org>
Acked-by: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: AKASHI Takahiro <takahiro.akashi-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Cc: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
Cc: David Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: erik.schmauss-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org
Cc: fanc.fnst-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org
Cc: "H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
Cc: Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Cc: lenb-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org
Cc: linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Philipp Rudo <prudo-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
Cc: rafael.j.wysocki-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org
Cc: robert.moore-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org
Cc: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Cc: x86-ml <x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Yannik Sembritzki <yannik-Ed5pum6jkczxnD6Ig1nlyA@public.gmane.org>
Link: https://lkml.kernel.org/r/20190118111310.29589-2-kasong-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
Signed-off-by: Sasha Levin <sashal-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
 arch/x86/kernel/kexec-bzimage64.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 928b0c6083c9..4d948d87f01c 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -167,6 +167,9 @@ setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
 	struct efi_info *current_ei = &boot_params.efi_info;
 	struct efi_info *ei = &params->efi_info;
 
+	if (!efi_enabled(EFI_RUNTIME_SERVICES))
+		return 0;
+
 	if (!current_ei->efi_memmap_size)
 		return 0;
 
-- 
2.19.1