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Groups > linux.kernel > #1527495
| From | Lukas Wunner <lukas@wunner.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 5/6] efi: Disable secure boot if shim is in insecure mode |
| Date | 2016-11-22 14:10 +0100 |
| Message-ID | <sGiZI-7z8-3@gated-at.bofh.it> (permalink) |
| References | <sEw14-1T0-39@gated-at.bofh.it> <sG7hT-8nV-11@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue, Nov 22, 2016 at 12:32:08AM +0000, David Howells wrote:
> From: Josh Boyer <jwboyer@fedoraproject.org>
>
> A user can manually tell the shim boot loader to disable validation of
> images it loads. When a user does this, it creates a UEFI variable called
> MokSBState that does not have the runtime attribute set. Given that the
> user explicitly disabled validation, we can honor that and not enable
> secure boot mode if that variable is set.
>
> Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
> Signed-off-by: David Howells <dhowells@redhat.com>
> ---
>
> drivers/firmware/efi/libstub/secureboot.c | 22 +++++++++++++++++++++-
> 1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/efi/libstub/secureboot.c b/drivers/firmware/efi/libstub/secureboot.c
> index e44d8c9ee150..d928398a3a52 100644
> --- a/drivers/firmware/efi/libstub/secureboot.c
> +++ b/drivers/firmware/efi/libstub/secureboot.c
> @@ -23,10 +23,14 @@ int efi_get_secureboot(void)
> 'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 };
> static const efi_char16_t const sm_var_name[] = {
> 'S', 'e', 't', 'u', 'p', 'M', 'o', 'd', 'e', 0 };
> + static efi_char16_t const MokSBState_var_name[] = {
> + 'M', 'o', 'k', 'S', 'B', 'S', 't', 'a', 't', 'e', 0 };
>
> static const efi_guid_t var_guid = EFI_GLOBAL_VARIABLE_GUID;
> + static const efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID;
>
> - u8 val;
> + u32 attr;
> + u8 val, moksbstate;
> unsigned long size = sizeof(val);
> efi_status_t status;
>
> @@ -50,6 +54,22 @@ int efi_get_secureboot(void)
> if (val == 1)
> return 0;
>
> + /* See if a user has put shim into insecure mode. If so, and if the
> + * variable doesn't have the runtime attribute set, we might as well
> + * honor that.
> + */
> + size = sizeof(moksbstate);
> + status = f_getvar((efi_char16_t *)MokSBState_var_name, &shim_guid,
> + &attr, &size, &moksbstate);
Please use efi_call_runtime() instead of f_getvar().
> +
> + /* If it fails, we don't care why. Default to secure */
> + if (status != EFI_SUCCESS)
> + return 1;
> +
> + if (!(attr & EFI_VARIABLE_RUNTIME_ACCESS) &&
> + moksbstate == 1)
This would fit on a single line.
Thanks,
Lukas
> + return 0;
> +
> return 1;
>
> out_efi_err:
>
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[PATCH 02/16] efi: Get the secure boot status David Howells <dhowells@redhat.com> - 2016-11-16 22:50 +0100
Re: [PATCH 02/16] efi: Get the secure boot status Lukas Wunner <lukas@wunner.de> - 2016-11-17 15:40 +0100
Re: [PATCH 02/16] efi: Get the secure boot status David Howells <dhowells@redhat.com> - 2016-11-21 12:50 +0100
Re: [PATCH 02/16] efi: Get the secure boot status Lukas Wunner <lukas@wunner.de> - 2016-11-21 21:00 +0100
Re: [PATCH 02/16] efi: Get the secure boot status David Howells <dhowells@redhat.com> - 2016-11-21 12:50 +0100
Re: [PATCH 02/16] efi: Get the secure boot status Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2016-11-21 13:00 +0100
Re: [PATCH 02/16] efi: Get the secure boot status David Howells <dhowells@redhat.com> - 2016-11-21 13:50 +0100
Re: [PATCH 02/16] efi: Get the secure boot status Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2016-11-21 14:20 +0100
Re: [PATCH 02/16] efi: Get the secure boot status Lukas Wunner <lukas@wunner.de> - 2016-11-21 16:20 +0100
Re: [PATCH 02/16] efi: Get the secure boot status Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2016-11-21 16:30 +0100
[PATCH 6/6] efi: Add EFI_SECURE_BOOT bit David Howells <dhowells@redhat.com> - 2016-11-22 01:40 +0100
Re: [PATCH 6/6] efi: Add EFI_SECURE_BOOT bit Lukas Wunner <lukas@wunner.de> - 2016-11-22 14:10 +0100
[PATCH 5/6] efi: Disable secure boot if shim is in insecure mode David Howells <dhowells@redhat.com> - 2016-11-22 01:40 +0100
Re: [PATCH 5/6] efi: Disable secure boot if shim is in insecure mode Lukas Wunner <lukas@wunner.de> - 2016-11-22 14:10 +0100
[PATCH 2/6] arm/efi: Allow invocation of arbitrary runtime services David Howells <dhowells@redhat.com> - 2016-11-22 01:40 +0100
[PATCH 1/6] x86/efi: Allow invocation of arbitrary runtime services David Howells <dhowells@redhat.com> - 2016-11-22 01:40 +0100
Re: [PATCH 1/6] x86/efi: Allow invocation of arbitrary runtime services Lukas Wunner <lukas@wunner.de> - 2016-11-22 11:20 +0100
Re: [PATCH 1/6] x86/efi: Allow invocation of arbitrary runtime services David Howells <dhowells@redhat.com> - 2016-11-22 15:20 +0100
Re: [PATCH 1/6] x86/efi: Allow invocation of arbitrary runtime services Joe Perches <joe@perches.com> - 2016-11-22 16:00 +0100
Re: [PATCH 1/6] x86/efi: Allow invocation of arbitrary runtime services David Howells <dhowells@redhat.com> - 2016-11-22 17:00 +0100
Re: [PATCH 1/6] x86/efi: Allow invocation of arbitrary runtime services Joe Perches <joe@perches.com> - 2016-11-22 17:30 +0100
Re: [PATCH 1/6] x86/efi: Allow invocation of arbitrary runtime services David Howells <dhowells@redhat.com> - 2016-11-22 17:50 +0100
Re: [PATCH 1/6] x86/efi: Allow invocation of arbitrary runtime services Joe Perches <joe@perches.com> - 2016-11-22 18:00 +0100
[PATCH 3/6] efi: Add SHIM and image security database GUID definitions David Howells <dhowells@redhat.com> - 2016-11-22 01:40 +0100
[PATCH 4/6] efi: Get the secure boot status David Howells <dhowells@redhat.com> - 2016-11-22 01:40 +0100
Re: [PATCH 4/6] efi: Get the secure boot status Lukas Wunner <lukas@wunner.de> - 2016-11-22 11:50 +0100
Re: [PATCH 4/6] efi: Get the secure boot status Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2016-11-22 11:50 +0100
Re: [PATCH 4/6] efi: Get the secure boot status David Howells <dhowells@redhat.com> - 2016-11-22 15:50 +0100
Re: [PATCH 4/6] efi: Get the secure boot status David Howells <dhowells@redhat.com> - 2016-11-22 16:00 +0100
Re: [PATCH 4/6] efi: Get the secure boot status Lukas Wunner <lukas@wunner.de> - 2016-11-22 21:30 +0100
Re: [PATCH 4/6] efi: Get the secure boot status David Howells <dhowells@redhat.com> - 2016-11-23 01:10 +0100
Re: [PATCH 4/6] efi: Get the secure boot status David Howells <dhowells@redhat.com> - 2016-11-22 16:10 +0100
Re: [PATCH 4/6] efi: Get the secure boot status Lukas Wunner <lukas@wunner.de> - 2016-11-22 21:40 +0100
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