Adding upstream version 252.22.upstream/252.22

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 415 insertions, 0 deletions

diff --git a/src/boot/efi/stub.c b/src/boot/efi/stub.c
new file mode 100644
index 0000000..7c42a16
--- /dev/null
+++ b/src/boot/efi/stub.c
@@ -0,0 +1,415 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <efi.h>
+#include <efilib.h>
+
+#include "cpio.h"
+#include "devicetree.h"
+#include "disk.h"
+#include "graphics.h"
+#include "linux.h"
+#include "measure.h"
+#include "pe.h"
+#include "secure-boot.h"
+#include "splash.h"
+#include "tpm-pcr.h"
+#include "util.h"
+
+/* magic string to find in the binary image */
+_used_ _section_(".sdmagic") static const char magic[] = "#### LoaderInfo: systemd-stub " GIT_VERSION " ####";
+
+static EFI_STATUS combine_initrd(
+                EFI_PHYSICAL_ADDRESS initrd_base, UINTN initrd_size,
+                const void * const extra_initrds[], const size_t extra_initrd_sizes[], size_t n_extra_initrds,
+                Pages *ret_initr_pages, UINTN *ret_initrd_size) {
+
+        UINTN n;
+
+        assert(ret_initr_pages);
+        assert(ret_initrd_size);
+
+        /* Combines four initrds into one, by simple concatenation in memory */
+
+        n = ALIGN4(initrd_size); /* main initrd might not be padded yet */
+
+        for (size_t i = 0; i < n_extra_initrds; i++) {
+                if (!extra_initrds[i])
+                        continue;
+
+                if (n > UINTN_MAX - extra_initrd_sizes[i])
+                        return EFI_OUT_OF_RESOURCES;
+
+                n += extra_initrd_sizes[i];
+        }
+
+        _cleanup_pages_ Pages pages = xmalloc_pages(
+                        AllocateMaxAddress,
+                        EfiLoaderData,
+                        EFI_SIZE_TO_PAGES(n),
+                        UINT32_MAX /* Below 4G boundary. */);
+        uint8_t *p = PHYSICAL_ADDRESS_TO_POINTER(pages.addr);
+        if (initrd_base != 0) {
+                UINTN pad;
+
+                /* Order matters, the real initrd must come first, since it might include microcode updates
+                 * which the kernel only looks for in the first cpio archive */
+                p = mempcpy(p, PHYSICAL_ADDRESS_TO_POINTER(initrd_base), initrd_size);
+
+                pad = ALIGN4(initrd_size) - initrd_size;
+                if (pad > 0)  {
+                        memset(p, 0, pad);
+                        p += pad;
+                }
+        }
+
+        for (size_t i = 0; i < n_extra_initrds; i++) {
+                if (!extra_initrds[i])
+                        continue;
+
+                p = mempcpy(p, extra_initrds[i], extra_initrd_sizes[i]);
+        }
+
+        assert(PHYSICAL_ADDRESS_TO_POINTER(pages.addr + n) == p);
+
+        *ret_initr_pages = pages;
+        *ret_initrd_size = n;
+        pages.n_pages = 0;
+
+        return EFI_SUCCESS;
+}
+
+static void export_variables(EFI_LOADED_IMAGE_PROTOCOL *loaded_image) {
+        static const uint64_t stub_features =
+                EFI_STUB_FEATURE_REPORT_BOOT_PARTITION |    /* We set LoaderDevicePartUUID */
+                EFI_STUB_FEATURE_PICK_UP_CREDENTIALS |      /* We pick up credentials from the boot partition */
+                EFI_STUB_FEATURE_PICK_UP_SYSEXTS |          /* We pick up system extensions from the boot partition */
+                EFI_STUB_FEATURE_THREE_PCRS |               /* We can measure kernel image, parameters and sysext */
+                0;
+
+        char16_t uuid[37];
+
+        assert(loaded_image);
+
+        /* Export the device path this image is started from, if it's not set yet */
+        if (efivar_get_raw(LOADER_GUID, L"LoaderDevicePartUUID", NULL, NULL) != EFI_SUCCESS)
+                if (disk_get_part_uuid(loaded_image->DeviceHandle, uuid) == EFI_SUCCESS)
+                        efivar_set(LOADER_GUID, L"LoaderDevicePartUUID", uuid, 0);
+
+        /* If LoaderImageIdentifier is not set, assume the image with this stub was loaded directly from the
+         * UEFI firmware without any boot loader, and hence set the LoaderImageIdentifier ourselves. Note
+         * that some boot chain loaders neither set LoaderImageIdentifier nor make FilePath available to us,
+         * in which case there's simple nothing to set for us. (The UEFI spec doesn't really say who's wrong
+         * here, i.e. whether FilePath may be NULL or not, hence handle this gracefully and check if FilePath
+         * is non-NULL explicitly.) */
+        if (efivar_get_raw(LOADER_GUID, L"LoaderImageIdentifier", NULL, NULL) != EFI_SUCCESS &&
+            loaded_image->FilePath) {
+                _cleanup_free_ char16_t *s = NULL;
+                if (device_path_to_str(loaded_image->FilePath, &s) == EFI_SUCCESS)
+                        efivar_set(LOADER_GUID, L"LoaderImageIdentifier", s, 0);
+        }
+
+        /* if LoaderFirmwareInfo is not set, let's set it */
+        if (efivar_get_raw(LOADER_GUID, L"LoaderFirmwareInfo", NULL, NULL) != EFI_SUCCESS) {
+                _cleanup_free_ char16_t *s = NULL;
+                s = xpool_print(L"%s %u.%02u", ST->FirmwareVendor, ST->FirmwareRevision >> 16, ST->FirmwareRevision & 0xffff);
+                efivar_set(LOADER_GUID, L"LoaderFirmwareInfo", s, 0);
+        }
+
+        /* ditto for LoaderFirmwareType */
+        if (efivar_get_raw(LOADER_GUID, L"LoaderFirmwareType", NULL, NULL) != EFI_SUCCESS) {
+                _cleanup_free_ char16_t *s = NULL;
+                s = xpool_print(L"UEFI %u.%02u", ST->Hdr.Revision >> 16, ST->Hdr.Revision & 0xffff);
+                efivar_set(LOADER_GUID, L"LoaderFirmwareType", s, 0);
+        }
+
+
+        /* add StubInfo (this is one is owned by the stub, hence we unconditionally override this with our
+         * own data) */
+        (void) efivar_set(LOADER_GUID, L"StubInfo", L"systemd-stub " GIT_VERSION, 0);
+
+        (void) efivar_set_uint64_le(LOADER_GUID, L"StubFeatures", stub_features, 0);
+}
+
+static bool use_load_options(
+                EFI_HANDLE stub_image,
+                EFI_LOADED_IMAGE_PROTOCOL *loaded_image,
+                bool have_cmdline,
+                char16_t **ret) {
+
+        assert(stub_image);
+        assert(loaded_image);
+        assert(ret);
+
+        /* We only allow custom command lines if we aren't in secure boot or if no cmdline was baked into
+         * the stub image. */
+        if (secure_boot_enabled() && have_cmdline)
+                return false;
+
+        /* We also do a superficial check whether first character of passed command line
+         * is printable character (for compat with some Dell systems which fill in garbage?). */
+        if (loaded_image->LoadOptionsSize < sizeof(char16_t) || ((char16_t *) loaded_image->LoadOptions)[0] <= 0x1F)
+                return false;
+
+        /* The UEFI shell registers EFI_SHELL_PARAMETERS_PROTOCOL onto images it runs. This lets us know that
+         * LoadOptions starts with the stub binary path which we want to strip off. */
+        EFI_SHELL_PARAMETERS_PROTOCOL *shell;
+        if (BS->HandleProtocol(stub_image, &(EFI_GUID) EFI_SHELL_PARAMETERS_PROTOCOL_GUID, (void **) &shell)
+            != EFI_SUCCESS) {
+                /* Not running from EFI shell, use entire LoadOptions. Note that LoadOptions is a void*, so
+                 * it could be anything! */
+                *ret = xstrndup16(loaded_image->LoadOptions, loaded_image->LoadOptionsSize / sizeof(char16_t));
+                mangle_stub_cmdline(*ret);
+                return true;
+        }
+
+        if (shell->Argc < 2)
+                /* No arguments were provided? Then we fall back to built-in cmdline. */
+                return false;
+
+        /* Assemble the command line ourselves without our stub path. */
+        *ret = xstrdup16(shell->Argv[1]);
+        for (size_t i = 2; i < shell->Argc; i++) {
+                _cleanup_free_ char16_t *old = *ret;
+                *ret = xpool_print(u"%s %s", old, shell->Argv[i]);
+        }
+
+        mangle_stub_cmdline(*ret);
+        return true;
+}
+
+EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *sys_table) {
+        _cleanup_free_ void *credential_initrd = NULL, *global_credential_initrd = NULL, *sysext_initrd = NULL, *pcrsig_initrd = NULL, *pcrpkey_initrd = NULL;
+        size_t credential_initrd_size = 0, global_credential_initrd_size = 0, sysext_initrd_size = 0, pcrsig_initrd_size = 0, pcrpkey_initrd_size = 0;
+        size_t linux_size, initrd_size, dt_size;
+        EFI_PHYSICAL_ADDRESS linux_base, initrd_base, dt_base;
+        _cleanup_(devicetree_cleanup) struct devicetree_state dt_state = {};
+        EFI_LOADED_IMAGE_PROTOCOL *loaded_image;
+        size_t addrs[_UNIFIED_SECTION_MAX] = {}, szs[_UNIFIED_SECTION_MAX] = {};
+        _cleanup_free_ char16_t *cmdline = NULL;
+        int sections_measured = -1, parameters_measured = -1;
+        bool sysext_measured = false, m;
+        EFI_STATUS err;
+
+        InitializeLib(image, sys_table);
+        debug_hook(L"systemd-stub");
+        /* Uncomment the next line if you need to wait for debugger. */
+        // debug_break();
+
+        err = BS->OpenProtocol(
+                        image,
+                        &LoadedImageProtocol,
+                        (void **)&loaded_image,
+                        image,
+                        NULL,
+                        EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+        if (err != EFI_SUCCESS)
+                return log_error_status_stall(err, L"Error getting a LoadedImageProtocol handle: %r", err);
+
+        err = pe_memory_locate_sections(loaded_image->ImageBase, unified_sections, addrs, szs);
+        if (err != EFI_SUCCESS || szs[UNIFIED_SECTION_LINUX] == 0) {
+                if (err == EFI_SUCCESS)
+                        err = EFI_NOT_FOUND;
+                return log_error_status_stall(err, L"Unable to locate embedded .linux section: %r", err);
+        }
+
+        /* Measure all "payload" of this PE image into a separate PCR (i.e. where nothing else is written
+         * into so far), so that we have one PCR that we can nicely write policies against because it
+         * contains all static data of this image, and thus can be easily be pre-calculated. */
+        for (UnifiedSection section = 0; section < _UNIFIED_SECTION_MAX; section++) {
+
+                if (!unified_section_measure(section)) /* shall not measure? */
+                        continue;
+
+                if (szs[section] == 0) /* not found */
+                        continue;
+
+                m = false;
+
+                /* First measure the name of the section */
+                (void) tpm_log_event_ascii(
+                                TPM_PCR_INDEX_KERNEL_IMAGE,
+                                POINTER_TO_PHYSICAL_ADDRESS(unified_sections[section]),
+                                strsize8(unified_sections[section]), /* including NUL byte */
+                                unified_sections[section],
+                                &m);
+
+                sections_measured = sections_measured < 0 ? m : (sections_measured && m);
+
+                /* Then measure the data of the section */
+                (void) tpm_log_event_ascii(
+                                TPM_PCR_INDEX_KERNEL_IMAGE,
+                                POINTER_TO_PHYSICAL_ADDRESS(loaded_image->ImageBase) + addrs[section],
+                                szs[section],
+                                unified_sections[section],
+                                &m);
+
+                sections_measured = sections_measured < 0 ? m : (sections_measured && m);
+        }
+
+        /* After we are done, set an EFI variable that tells userspace this was done successfully, and encode
+         * in it which PCR was used. */
+        if (sections_measured > 0)
+                (void) efivar_set_uint_string(LOADER_GUID, L"StubPcrKernelImage", TPM_PCR_INDEX_KERNEL_IMAGE, 0);
+
+        /* Show splash screen as early as possible */
+        graphics_splash((const uint8_t*) loaded_image->ImageBase + addrs[UNIFIED_SECTION_SPLASH], szs[UNIFIED_SECTION_SPLASH]);
+
+        if (use_load_options(image, loaded_image, szs[UNIFIED_SECTION_CMDLINE] > 0, &cmdline)) {
+                /* Let's measure the passed kernel command line into the TPM. Note that this possibly
+                 * duplicates what we already did in the boot menu, if that was already used. However, since
+                 * we want the boot menu to support an EFI binary, and want to this stub to be usable from
+                 * any boot menu, let's measure things anyway. */
+                m = false;
+                (void) tpm_log_load_options(cmdline, &m);
+                parameters_measured = m;
+        } else if (szs[UNIFIED_SECTION_CMDLINE] > 0) {
+                cmdline = xstrn8_to_16(
+                                (char *) loaded_image->ImageBase + addrs[UNIFIED_SECTION_CMDLINE],
+                                szs[UNIFIED_SECTION_CMDLINE]);
+                mangle_stub_cmdline(cmdline);
+        }
+
+        export_variables(loaded_image);
+
+        if (pack_cpio(loaded_image,
+                      NULL,
+                      L".cred",
+                      ".extra/credentials",
+                      /* dir_mode= */ 0500,
+                      /* access_mode= */ 0400,
+                      /* tpm_pcr= */ (uint32_t[]) { TPM_PCR_INDEX_KERNEL_PARAMETERS, TPM_PCR_INDEX_KERNEL_PARAMETERS_COMPAT },
+                      /* n_tpm_pcr= */ 2,
+                      L"Credentials initrd",
+                      &credential_initrd,
+                      &credential_initrd_size,
+                      &m) == EFI_SUCCESS)
+                parameters_measured = parameters_measured < 0 ? m : (parameters_measured && m);
+
+        if (pack_cpio(loaded_image,
+                      L"\\loader\\credentials",
+                      L".cred",
+                      ".extra/global_credentials",
+                      /* dir_mode= */ 0500,
+                      /* access_mode= */ 0400,
+                      /* tpm_pcr= */ (uint32_t[]) { TPM_PCR_INDEX_KERNEL_PARAMETERS, TPM_PCR_INDEX_KERNEL_PARAMETERS_COMPAT },
+                      /* n_tpm_pcr= */ 2,
+                      L"Global credentials initrd",
+                      &global_credential_initrd,
+                      &global_credential_initrd_size,
+                      &m) == EFI_SUCCESS)
+                parameters_measured = parameters_measured < 0 ? m : (parameters_measured && m);
+
+        if (pack_cpio(loaded_image,
+                      NULL,
+                      L".raw",
+                      ".extra/sysext",
+                      /* dir_mode= */ 0555,
+                      /* access_mode= */ 0444,
+                      /* tpm_pcr= */ (uint32_t[]) { TPM_PCR_INDEX_INITRD_SYSEXTS },
+                      /* n_tpm_pcr= */ 1,
+                      L"System extension initrd",
+                      &sysext_initrd,
+                      &sysext_initrd_size,
+                      &m) == EFI_SUCCESS)
+                sysext_measured = m;
+
+        if (parameters_measured > 0)
+                (void) efivar_set_uint_string(LOADER_GUID, L"StubPcrKernelParameters", TPM_PCR_INDEX_KERNEL_PARAMETERS, 0);
+        if (sysext_measured)
+                (void) efivar_set_uint_string(LOADER_GUID, L"StubPcrInitRDSysExts", TPM_PCR_INDEX_INITRD_SYSEXTS, 0);
+
+        /* If the PCR signature was embedded in the PE image, then let's wrap it in a cpio and also pass it
+         * to the kernel, so that it can be read from /.extra/tpm2-pcr-signature.json. Note that this section
+         * is not measured, neither as raw section (see above), nor as cpio (here), because it is the
+         * signature of expected PCR values, i.e. its input are PCR measurements, and hence it shouldn't
+         * itself be input for PCR measurements. */
+        if (szs[UNIFIED_SECTION_PCRSIG] > 0)
+                (void) pack_cpio_literal(
+                                (uint8_t*) loaded_image->ImageBase + addrs[UNIFIED_SECTION_PCRSIG],
+                                szs[UNIFIED_SECTION_PCRSIG],
+                                ".extra",
+                                L"tpm2-pcr-signature.json",
+                                /* dir_mode= */ 0555,
+                                /* access_mode= */ 0444,
+                                /* tpm_pcr= */ NULL,
+                                /* n_tpm_pcr= */ 0,
+                                /* tpm_description= */ NULL,
+                                &pcrsig_initrd,
+                                &pcrsig_initrd_size,
+                                /* ret_measured= */ NULL);
+
+        /* If the public key used for the PCR signatures was embedded in the PE image, then let's wrap it in
+         * a cpio and also pass it to the kernel, so that it can be read from
+         * /.extra/tpm2-pcr-public-key.pem. This section is already measure above, hence we won't measure the
+         * cpio. */
+        if (szs[UNIFIED_SECTION_PCRPKEY] > 0)
+                (void) pack_cpio_literal(
+                                (uint8_t*) loaded_image->ImageBase + addrs[UNIFIED_SECTION_PCRPKEY],
+                                szs[UNIFIED_SECTION_PCRPKEY],
+                                ".extra",
+                                L"tpm2-pcr-public-key.pem",
+                                /* dir_mode= */ 0555,
+                                /* access_mode= */ 0444,
+                                /* tpm_pcr= */ NULL,
+                                /* n_tpm_pcr= */ 0,
+                                /* tpm_description= */ NULL,
+                                &pcrpkey_initrd,
+                                &pcrpkey_initrd_size,
+                                /* ret_measured= */ NULL);
+
+        linux_size = szs[UNIFIED_SECTION_LINUX];
+        linux_base = POINTER_TO_PHYSICAL_ADDRESS(loaded_image->ImageBase) + addrs[UNIFIED_SECTION_LINUX];
+
+        initrd_size = szs[UNIFIED_SECTION_INITRD];
+        initrd_base = initrd_size != 0 ? POINTER_TO_PHYSICAL_ADDRESS(loaded_image->ImageBase) + addrs[UNIFIED_SECTION_INITRD] : 0;
+
+        dt_size = szs[UNIFIED_SECTION_DTB];
+        dt_base = dt_size != 0 ? POINTER_TO_PHYSICAL_ADDRESS(loaded_image->ImageBase) + addrs[UNIFIED_SECTION_DTB] : 0;
+
+        _cleanup_pages_ Pages initrd_pages = {};
+        if (credential_initrd || global_credential_initrd || sysext_initrd || pcrsig_initrd || pcrpkey_initrd) {
+                /* If we have generated initrds dynamically, let's combine them with the built-in initrd. */
+                err = combine_initrd(
+                                initrd_base, initrd_size,
+                                (const void*const[]) {
+                                        credential_initrd,
+                                        global_credential_initrd,
+                                        sysext_initrd,
+                                        pcrsig_initrd,
+                                        pcrpkey_initrd,
+                                },
+                                (const size_t[]) {
+                                        credential_initrd_size,
+                                        global_credential_initrd_size,
+                                        sysext_initrd_size,
+                                        pcrsig_initrd_size,
+                                        pcrpkey_initrd_size,
+                                },
+                                5,
+                                &initrd_pages, &initrd_size);
+                if (err != EFI_SUCCESS)
+                        return err;
+
+                initrd_base = initrd_pages.addr;
+
+                /* Given these might be large let's free them explicitly, quickly. */
+                credential_initrd = mfree(credential_initrd);
+                global_credential_initrd = mfree(global_credential_initrd);
+                sysext_initrd = mfree(sysext_initrd);
+                pcrsig_initrd = mfree(pcrsig_initrd);
+                pcrpkey_initrd = mfree(pcrpkey_initrd);
+        }
+
+        if (dt_size > 0) {
+                err = devicetree_install_from_memory(
+                                &dt_state, PHYSICAL_ADDRESS_TO_POINTER(dt_base), dt_size);
+                if (err != EFI_SUCCESS)
+                        log_error_stall(L"Error loading embedded devicetree: %r", err);
+        }
+
+        err = linux_exec(image, cmdline,
+                         PHYSICAL_ADDRESS_TO_POINTER(linux_base), linux_size,
+                         PHYSICAL_ADDRESS_TO_POINTER(initrd_base), initrd_size);
+        graphics_mode(false);
+        return err;
+}