FAILED: patch "[PATCH] Fix kexec forbidding kernels signed with keys in the" failed to apply to 4.9-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From ea93102f32244e3f45c8b26260be77ed0cc1d16c Mon Sep 17 00:00:00 2001
From: Yannik Sembritzki <yannik@sembritzki.me>
Date: Thu, 16 Aug 2018 14:05:23 +0100
Subject: [PATCH] Fix kexec forbidding kernels signed with keys in the
 secondary keyring to boot

The split of .system_keyring into .builtin_trusted_keys and
.secondary_trusted_keys broke kexec, thereby preventing kernels signed by
keys which are now in the secondary keyring from being kexec'd.

Fix this by passing VERIFY_USE_SECONDARY_KEYRING to
verify_pefile_signature().

Fixes: d3bfe84129f6 ("certs: Add a secondary system keyring that can be added to dynamically")
Signed-off-by: Yannik Sembritzki <yannik@sembritzki.me>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: kexec@lists.infradead.org
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 7326078eaa7a..278cd07228dd 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -532,7 +532,7 @@ static int bzImage64_cleanup(void *loader_data)
 static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
 {
 	return verify_pefile_signature(kernel, kernel_len,
-				       NULL,
+				       VERIFY_USE_SECONDARY_KEYRING,
 				       VERIFYING_KEXEC_PE_SIGNATURE);
 }
 #endif