Commit 54993156 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'efi-fixes-for-v6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi 

Pull EFI fix from Ard Biesheuvel:

 - Followup fix for the EFI boot sequence refactor, which may result in
   physical KASLR putting the kernel in a region which is being used for
   a special purpose via a command line argument.

* tag 'efi-fixes-for-v6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  x86/efistub: Omit physical KASLR when memory reservations exist
parents 85672639 15aa8fb8

drivers/firmware/efi/libstub/x86-stub.c

+26 −2
Original line number Diff line number Diff line
@@ -776,6 +776,26 @@ static void error(char *str) 
	efi_warn("Decompression failed: %s\n", str);

}



static const char *cmdline_memmap_override;



static efi_status_t parse_options(const char *cmdline)

{

	static const char opts[][14] = {

		"mem=", "memmap=", "efi_fake_mem=", "hugepages="

	};



	for (int i = 0; i < ARRAY_SIZE(opts); i++) {

		const char *p = strstr(cmdline, opts[i]);



		if (p == cmdline || (p > cmdline && isspace(p[-1]))) {

			cmdline_memmap_override = opts[i];

			break;

		}

	}



	return efi_parse_options(cmdline);

}



static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)

{

	unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
@@ -807,6 +827,10 @@ static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry) 
		    !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) {

			efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n");

			seed[0] = 0;

		} else if (cmdline_memmap_override) {

			efi_info("%s detected on the kernel command line - disabling physical KASLR\n",

				 cmdline_memmap_override);

			seed[0] = 0;

		}



		boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
@@ -883,7 +907,7 @@ void __noreturn efi_stub_entry(efi_handle_t handle, 
	}



#ifdef CONFIG_CMDLINE_BOOL

	status = efi_parse_options(CONFIG_CMDLINE);

	status = parse_options(CONFIG_CMDLINE);

	if (status != EFI_SUCCESS) {

		efi_err("Failed to parse options\n");

		goto fail;
@@ -892,7 +916,7 @@ void __noreturn efi_stub_entry(efi_handle_t handle, 
	if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {

		unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |

					       ((u64)boot_params->ext_cmd_line_ptr << 32));

		status = efi_parse_options((char *)cmdline_paddr);

		status = parse_options((char *)cmdline_paddr);

		if (status != EFI_SUCCESS) {

			efi_err("Failed to parse options\n");

			goto fail;