From: AKASHI Takahiro <takahiro.akashi@linaro.org>
To: catalin.marinas@arm.com, will.deacon@arm.com,
dhowells@redhat.com, vgoyal@redhat.com,
herbert@gondor.apana.org.au, davem@davemloft.net,
dyoung@redhat.com, bhe@redhat.com, arnd@arndb.de
Cc: ard.biesheuvel@linaro.org, james.morse@arm.com,
bhsharma@redhat.com, kexec@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
AKASHI Takahiro <takahiro.akashi@linaro.org>
Subject: [PATCH v10 13/14] arm64: kexec_file: add kernel signature verification support
Date: Sat, 23 Jun 2018 11:20:57 +0900 [thread overview]
Message-ID: <20180623022058.10935-14-takahiro.akashi@linaro.org> (raw)
In-Reply-To: <20180623022058.10935-1-takahiro.akashi@linaro.org>
With this patch, kernel verification can be done without IMA security
subsystem enabled. Turn on CONFIG_KEXEC_VERIFY_SIG instead.
On x86, a signature is embedded into a PE file (Microsoft's format) header
of binary. Since arm64's "Image" can also be seen as a PE file as far as
CONFIG_EFI is enabled, we adopt this format for kernel signing.
You can create a signed kernel image with:
$ sbsign --key ${KEY} --cert ${CERT} Image
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
arch/arm64/Kconfig | 24 ++++++++++++++++++++++++
arch/arm64/kernel/kexec_image.c | 15 +++++++++++++++
2 files changed, 39 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index f68318f61c85..5133c22a01ab 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -845,6 +845,30 @@ config KEXEC_FILE
for kernel and initramfs as opposed to list of segments as
accepted by previous system call.
+config KEXEC_VERIFY_SIG
+ bool "Verify kernel signature during kexec_file_load() syscall"
+ depends on KEXEC_FILE
+ help
+ Select this option to verify a signature with loaded kernel
+ image. If configured, any attempt of loading a image without
+ valid signature will fail.
+
+ In addition to that option, you need to enable signature
+ verification for the corresponding kernel image type being
+ loaded in order for this to work.
+
+config KEXEC_IMAGE_VERIFY_SIG
+ bool "Enable Image signature verification support"
+ default y
+ depends on KEXEC_VERIFY_SIG
+ depends on EFI && SIGNED_PE_FILE_VERIFICATION
+ help
+ Enable Image signature verification support.
+
+comment "Image signature verification is missing yet"
+ depends on KEXEC_VERIFY_SIG
+ depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
+
config CRASH_DUMP
bool "Build kdump crash kernel"
help
diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c
index df1e341d3a28..bb0a95add197 100644
--- a/arch/arm64/kernel/kexec_image.c
+++ b/arch/arm64/kernel/kexec_image.c
@@ -13,6 +13,7 @@
#include <linux/kernel.h>
#include <linux/kexec.h>
#include <linux/string.h>
+#include <linux/verification.h>
#include <asm/boot.h>
#include <asm/byteorder.h>
#include <asm/cpufeature.h>
@@ -28,6 +29,9 @@ static int image_probe(const char *kernel_buf, unsigned long kernel_len)
!memcmp(&h->magic, ARM64_MAGIC, sizeof(ARM64_MAGIC)))
return -EINVAL;
+ pr_debug("PE format: %s\n",
+ memcmp(&h->mz_magic, "MZ", 2) ? "no" : "yes");
+
return 0;
}
@@ -107,7 +111,18 @@ static void *image_load(struct kimage *image,
return ERR_PTR(ret);
}
+#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG
+static int image_verify_sig(const char *kernel, unsigned long kernel_len)
+{
+ return verify_pefile_signature(kernel, kernel_len, NULL,
+ VERIFYING_KEXEC_PE_SIGNATURE);
+}
+#endif
+
const struct kexec_file_ops kexec_image_ops = {
.probe = image_probe,
.load = image_load,
+#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG
+ .verify_sig = image_verify_sig,
+#endif
};
--
2.17.0
next prev parent reply other threads:[~2018-06-23 2:21 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-23 2:20 [PATCH v10 00/14] arm64: kexec: add kexec_file_load() support AKASHI Takahiro
2018-06-23 2:20 ` [PATCH v10 01/14] asm-generic: add kexec_file_load system call to unistd.h AKASHI Takahiro
2018-06-23 2:20 ` [PATCH v10 02/14] kexec_file: make kexec_image_post_load_cleanup_default() global AKASHI Takahiro
2018-06-23 2:20 ` [PATCH v10 03/14] powerpc, kexec_file: factor out memblock-based arch_kexec_walk_mem() AKASHI Takahiro
2018-07-03 16:36 ` James Morse
2018-07-09 5:49 ` AKASHI Takahiro
2018-07-09 11:03 ` James Morse
2018-06-23 2:20 ` [PATCH v10 04/14] of/fdt: add helper functions for handling properties AKASHI Takahiro
2018-06-23 2:20 ` [PATCH v10 05/14] arm64: add image head flag definitions AKASHI Takahiro
2018-07-03 16:34 ` James Morse
2018-06-23 2:20 ` [PATCH v10 06/14] arm64: cpufeature: add MMFR0 helper functions AKASHI Takahiro
2018-07-03 16:33 ` James Morse
2018-06-23 2:20 ` [PATCH v10 07/14] arm64: enable KEXEC_FILE config AKASHI Takahiro
2018-07-03 16:33 ` James Morse
2018-07-09 6:31 ` AKASHI Takahiro
2018-06-23 2:20 ` [PATCH v10 08/14] arm64: kexec_file: load initrd and device-tree AKASHI Takahiro
2018-07-03 16:32 ` James Morse
2018-07-10 7:37 ` AKASHI Takahiro
2018-07-10 15:25 ` James Morse
2018-07-11 2:49 ` AKASHI Takahiro
2018-06-23 2:20 ` [PATCH v10 09/14] arm64: kexec_file: allow for loading Image-format kernel AKASHI Takahiro
2018-06-23 2:20 ` [PATCH v10 10/14] arm64: kexec_file: add crash dump support AKASHI Takahiro
2018-06-23 2:20 ` [PATCH v10 11/14] arm64: kexec_file: invoke the kernel without purgatory AKASHI Takahiro
2018-06-23 2:20 ` [PATCH v10 12/14] include: pe.h: remove message[] from mz header definition AKASHI Takahiro
2018-06-23 2:20 ` AKASHI Takahiro [this message]
2018-07-03 17:47 ` [PATCH v10 13/14] arm64: kexec_file: add kernel signature verification support James Morse
2018-07-09 9:01 ` AKASHI Takahiro
2018-06-23 2:20 ` [PATCH v10 14/14] arm64: kexec_file: add kaslr support AKASHI Takahiro
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180623022058.10935-14-takahiro.akashi@linaro.org \
--to=takahiro.akashi@linaro.org \
--cc=ard.biesheuvel@linaro.org \
--cc=arnd@arndb.de \
--cc=bhe@redhat.com \
--cc=bhsharma@redhat.com \
--cc=catalin.marinas@arm.com \
--cc=davem@davemloft.net \
--cc=dhowells@redhat.com \
--cc=dyoung@redhat.com \
--cc=herbert@gondor.apana.org.au \
--cc=james.morse@arm.com \
--cc=kexec@lists.infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=vgoyal@redhat.com \
--cc=will.deacon@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).