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From: David Howells <dhowells@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: gnomes@lxorguk.ukuu.org.uk, linux-efi@vger.kernel.org,
	matthew.garrett@nebula.com, gregkh@linuxfoundation.org,
	dhowells@redhat.com, linux-security-module@vger.kernel.org,
	keyrings@vger.kernel.org, Dave Young <dyoung@redhat.com>
Subject: [PATCH 08/24] Copy secure_boot flag in boot params across kexec reboot
Date: Wed, 05 Apr 2017 18:08:07 +0100	[thread overview]
Message-ID: <149141208783.30815.12896516831173762041.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <149141201983.30815.1240162780237131881.stgit@warthog.procyon.org.uk>

From: Dave Young <dyoung@redhat.com>

Kexec reboot in case secure boot being enabled does not keep the secure
boot mode in new kernel, so later one can load unsigned kernel via legacy
kexec_load.  In this state, the system is missing the protections provided
by secure boot.

Adding a patch to fix this by retain the secure_boot flag in original
kernel.

secure_boot flag in boot_params is set in EFI stub, but kexec bypasses the
stub.  Fixing this issue by copying secure_boot flag across kexec reboot.

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---

 arch/x86/kernel/kexec-bzimage64.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index d0a814a9d96a..3551bcaa1eaf 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -179,6 +179,7 @@ setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
 	if (efi_enabled(EFI_OLD_MEMMAP))
 		return 0;
 
+	params->secure_boot = boot_params.secure_boot;
 	ei->efi_loader_signature = current_ei->efi_loader_signature;
 	ei->efi_systab = current_ei->efi_systab;
 	ei->efi_systab_hi = current_ei->efi_systab_hi;

WARNING: multiple messages have this Message-ID (diff)
From: dhowells@redhat.com (David Howells)
To: linux-security-module@vger.kernel.org
Subject: [PATCH 08/24] Copy secure_boot flag in boot params across kexec reboot
Date: Wed, 05 Apr 2017 18:08:07 +0100	[thread overview]
Message-ID: <149141208783.30815.12896516831173762041.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <149141201983.30815.1240162780237131881.stgit@warthog.procyon.org.uk>

From: Dave Young <dyoung@redhat.com>

Kexec reboot in case secure boot being enabled does not keep the secure
boot mode in new kernel, so later one can load unsigned kernel via legacy
kexec_load.  In this state, the system is missing the protections provided
by secure boot.

Adding a patch to fix this by retain the secure_boot flag in original
kernel.

secure_boot flag in boot_params is set in EFI stub, but kexec bypasses the
stub.  Fixing this issue by copying secure_boot flag across kexec reboot.

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---

 arch/x86/kernel/kexec-bzimage64.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index d0a814a9d96a..3551bcaa1eaf 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -179,6 +179,7 @@ setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
 	if (efi_enabled(EFI_OLD_MEMMAP))
 		return 0;
 
+	params->secure_boot = boot_params.secure_boot;
 	ei->efi_loader_signature = current_ei->efi_loader_signature;
 	ei->efi_systab = current_ei->efi_systab;
 	ei->efi_systab_hi = current_ei->efi_systab_hi;

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  parent reply	other threads:[~2017-04-05 17:08 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-05 17:07 [PATCH 00/24] Kernel lockdown David Howells
2017-04-05 17:07 ` David Howells
2017-04-05 17:07 ` [PATCH 01/24] efi: Add EFI_SECURE_BOOT bit David Howells
2017-04-05 17:07   ` David Howells
2017-04-05 17:07   ` David Howells
2017-04-05 17:07 ` [PATCH 02/24] Add the ability to lock down access to the running kernel image David Howells
2017-04-05 17:07   ` David Howells
2017-04-05 17:07 ` [PATCH 03/24] efi: Lock down the kernel if booted in secure boot mode David Howells
2017-04-05 17:07   ` David Howells
2017-04-05 17:07 ` [PATCH 04/24] Enforce module signatures if the kernel is locked down David Howells
2017-04-05 17:07   ` David Howells
2017-04-05 17:07 ` [PATCH 05/24] Restrict /dev/mem and /dev/kmem when " David Howells
2017-04-05 17:07   ` David Howells
2017-04-05 17:07   ` David Howells
2017-04-05 17:07 ` [PATCH 06/24] Add a sysrq option to exit secure boot mode David Howells
2017-04-05 17:07   ` David Howells
2017-04-05 17:08 ` [PATCH 07/24] kexec: Disable at runtime if the kernel is locked down David Howells
2017-04-05 17:08   ` David Howells
2017-04-05 17:08   ` David Howells
2017-04-05 17:08 ` David Howells [this message]
2017-04-05 17:08   ` [PATCH 08/24] Copy secure_boot flag in boot params across kexec reboot David Howells
2017-04-07 16:32 ` [PATCH 00/24] Kernel lockdown Justin Forbes
2017-04-07 16:32   ` Justin Forbes
2017-04-05 17:09 David Howells
2017-04-05 17:11 ` [PATCH 08/24] Copy secure_boot flag in boot params across kexec reboot David Howells
2017-04-05 17:11   ` David Howells
2017-04-05 20:14 [PATCH 00/24] Kernel lockdown David Howells
2017-04-05 20:15 ` [PATCH 08/24] Copy secure_boot flag in boot params across kexec reboot David Howells
2017-04-05 20:15   ` David Howells
2017-04-05 20:15   ` David Howells

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