Re: [PATCH] efi: Do not import certificates from UEFI Secure Boot for T2 Macs

From: Aditya Garg <gargaditya08@live.com>
To: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Ard Biesheuvel <ardb@kernel.org>, Jeremy Kerr <jk@ozlabs.org>,
	"joeyli.kernel@gmail.com" <joeyli.kernel@gmail.com>,
	"zohar@linux.ibm.com" <zohar@linux.ibm.com>,
	"jmorris@namei.org" <jmorris@namei.org>,
	"eric.snowberg@oracle.com" <eric.snowberg@oracle.com>,
	"dhowells@redhat.com" <dhowells@redhat.com>,
	"jlee@suse.com" <jlee@suse.com>,
	"James.Bottomley@hansenpartnership.com" 
	<James.Bottomley@HansenPartnership.com>,
	"jarkko@kernel.org" <jarkko@kernel.org>,
	"mic@digikod.net" <mic@digikod.net>,
	"dmitry.kasatkin@gmail.com" <dmitry.kasatkin@gmail.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
	"linux-security-module@vger.kernel.org" 
	<linux-security-module@vger.kernel.org>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>,
	"keyrings@vger.kernel.org" <keyrings@vger.kernel.org>,
	"linux-integrity@vger.kernel.org"
	<linux-integrity@vger.kernel.org>,
	Orlando Chamberlain <redecorating@protonmail.com>,
	Aun-Ali Zaidi <admin@kodeit.net>
Subject: Re: [PATCH] efi: Do not import certificates from UEFI Secure Boot for T2 Macs
Date: Thu, 10 Feb 2022 05:49:50 +0000	[thread overview]
Message-ID: <2F1CC5DE-5A03-46D2-95E7-DD07A4EF2766@live.com> (raw)
In-Reply-To: <20220209193705.GA15463@srcf.ucam.org>


> ie, can you try something like this?
> 
> diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c
> index f3e54f6616f0..01cbd4811d1e 100644
> --- a/drivers/firmware/efi/runtime-wrappers.c
> +++ b/drivers/firmware/efi/runtime-wrappers.c
> @@ -32,6 +32,8 @@
> #include <linux/stringify.h>
> #include <linux/workqueue.h>
> #include <linux/completion.h>
> +#include <linux/ucs2_string.h>
> +#include <linux/slab.h>
> 
> #include <asm/efi.h>
> 
> @@ -203,6 +205,21 @@ static void efi_call_rts(struct work_struct *work)
> 				       (efi_time_t *)arg2);
> 		break;
> 	case EFI_GET_VARIABLE:
> +		unsigned long utf8_name_size;
> +		char *utf8_name;
> +		char guid_str[sizeof(efi_guid_t)+1];
> +
> +		utf8_name_size = ucs2_utf8size((efi_char16_t *)arg1);
> +		utf8_name = kmalloc(utf8_name_size+1, GFP_KERNEL);
> +		if (!utf8_name) {
> +			printk(KERN_INFO "failed to allocate UTF8 buffer\n");
> +			break;
> +		}
> +
> +		ucs2_as_utf8(utf8_name, (efi_char16_t *)arg1, utf8_name_size + 1);
> +		efi_guid_to_str((efi_guid_t *)arg2, guid_str);
> +
> +		printk(KERN_INFO "Reading EFI variable %s-%s\n", utf8_name, guid_str);
> 		status = efi_call_virt(get_variable, (efi_char16_t *)arg1,
> 				       (efi_guid_t *)arg2, (u32 *)arg3,
> 				       (unsigned long *)arg4, (void *)arg5);

Looks like there is some error in this patch


drivers/firmware/efi/runtime-wrappers.c:208:3: error: a label can only be part of a statement and a declaration is not a statement
  208 |   unsigned long utf8_name_size;
      |   ^~~~~~~~
drivers/firmware/efi/runtime-wrappers.c:209:3: error: expected expression before ‘char’
  209 |   char *utf8_name;
      |   ^~~~
drivers/firmware/efi/runtime-wrappers.c:210:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  210 |   char guid_str[sizeof(efi_guid_t)+1];
      |   ^~~~
drivers/firmware/efi/runtime-wrappers.c:213:3: error: ‘utf8_name’ undeclared (first use in this function)
  213 |   utf8_name = kmalloc(utf8_name_size+1, GFP_KERNEL);
      |   ^~~~~~~~~
drivers/firmware/efi/runtime-wrappers.c:213:3: note: each undeclared identifier is reported only once for each function it appears in
make[6]: *** [scripts/Makefile.build:287: drivers/firmware/efi/runtime-wrappers.o] Error 1
make[5]: *** [scripts/Makefile.build:549: drivers/firmware/efi] Error 2
make[4]: *** [scripts/Makefile.build:549: drivers/firmware] Error 2
make[4]: *** Waiting for unfinished jobs....