make the kernel accept UKIs (Unified Kernel Images) for kexec_file_load.
UKIs contain the kernel bzImage, initrd, and cmdline all packaged up as
one EFI application. The main advantage of this is that the whole
combination is signed together as a package for secure boot.
This implementation parses the UKI and passes the bzImage, initrd, and
cmdline to the normal bzImage loader.
Signed-off-by: Jan Hendrik Farr <kernel@xxxxxxxx>
---
arch/x86/include/asm/kexec-uki.h | 7 ++
arch/x86/include/asm/parse_pefile.h | 32 +++++++
arch/x86/kernel/Makefile | 2 +
arch/x86/kernel/kexec-uki.c | 113 +++++++++++++++++++++++++
arch/x86/kernel/machine_kexec_64.c | 2 +
arch/x86/kernel/parse_pefile.c | 110 ++++++++++++++++++++++++
crypto/asymmetric_keys/mscode_parser.c | 2 +-
crypto/asymmetric_keys/verify_pefile.c | 110 +++---------------------
crypto/asymmetric_keys/verify_pefile.h | 16 ----
9 files changed, 278 insertions(+), 116 deletions(-)
create mode 100644 arch/x86/include/asm/kexec-uki.h
create mode 100644 arch/x86/include/asm/parse_pefile.h
create mode 100644 arch/x86/kernel/kexec-uki.c
create mode 100644 arch/x86/kernel/parse_pefile.c
diff --git a/arch/x86/include/asm/kexec-uki.h b/arch/x86/include/asm/kexec-uki.h
new file mode 100644
index 000000000000..87fd2c6fb091
--- /dev/null
+++ b/arch/x86/include/asm/kexec-uki.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASM_KEXEC_UKI_H
+#define _ASM_KEXEC_UKI_H
+
+extern const struct kexec_file_ops kexec_uki_ops;
+
+#endif /* _ASM_KEXEC_UKI_H */
diff --git a/arch/x86/include/asm/parse_pefile.h b/arch/x86/include/asm/parse_pefile.h
new file mode 100644
index 000000000000..c29f8c98ee66
--- /dev/null
+++ b/arch/x86/include/asm/parse_pefile.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ *
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#ifndef _ASM_PARSE_PEFILE_H
+#define _ASM_PARSE_PEFILE_H
+
+#include <linux/pe.h>
+
+struct pefile_context {
+ unsigned header_size;
+ unsigned image_checksum_offset;
+ unsigned cert_dirent_offset;
+ unsigned n_data_dirents;
+ unsigned n_sections;
+ unsigned certs_size;
+ unsigned sig_offset;
+ unsigned sig_len;
+ const struct section_header *secs;
+
+ /* PKCS#7 MS Individual Code Signing content */
+ const void *digest; /* Digest */
+ unsigned digest_len; /* Digest length */
+ const char *digest_algo; /* Digest algorithm */
+};
+int pefile_parse_binary(const void *pebuf, unsigned int pelen,
+ struct pefile_context *ctx);
+
+#endif // _ASM_PARSE_PEFILE_H
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 3269a0e23d3a..8a37a977bf72 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -101,6 +101,8 @@ obj-$(CONFIG_CRASH_CORE) += crash_core_$(BITS).o
obj-$(CONFIG_KEXEC_CORE) += machine_kexec_$(BITS).o
obj-$(CONFIG_KEXEC_CORE) += relocate_kernel_$(BITS).o crash.o
obj-$(CONFIG_KEXEC_FILE) += kexec-bzimage64.o
+obj-$(CONFIG_KEXEC_FILE) += kexec-uki.o
+obj-$(CONFIG_KEXEC_FILE) += parse_pefile.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o
obj-y += kprobes/
obj-$(CONFIG_MODULES) += module.o
diff --git a/arch/x86/kernel/kexec-uki.c b/arch/x86/kernel/kexec-uki.c
new file mode 100644
index 000000000000..9275196a6b71
--- /dev/null
+++ b/arch/x86/kernel/kexec-uki.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Kexec UKI loader
+ *
+ * Copyright (C) 2023 Jan Hendrik Farr
+ *
+ * Authors:
+ * Jan Hendrik Farr <kernel@xxxxxxxx>
+ */
+
+#define pr_fmt(fmt) "kexec-uki: " fmt
+
+#include <linux/kernel.h>
+#include "linux/pe.h"
+#include <linux/kexec.h>
+#include <linux/err.h>
+
+#include <asm/kexec-uki.h>
+#include <asm/kexec-bzimage64.h>
+#include <asm/parse_pefile.h>
+
+static int find_section(struct pefile_context *ctx, const char *name,
+ const struct section_header **sec)
+{
+ for (int i = 0; i < ctx->n_sections; i++) {
+ const struct section_header *cur_sec = &ctx->secs[i];
+
+ if (!strncmp(cur_sec->name, name, ARRAY_SIZE(cur_sec->name))) {
+ *sec = cur_sec;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static int uki_probe(const char *buf, unsigned long len)
+{
+ int ret = -ENOEXEC;
+ struct pefile_context pe_ctx;
+
+ int r = pefile_parse_binary(buf, len, &pe_ctx);
+
+ if (r) {
+ pr_info("Not a UKI. Not a valid PE file\n");
+ return ret;
+ }
+
+ const struct section_header *_;
+
+ if (find_section(&pe_ctx, ".linux", &_) ||
+ find_section(&pe_ctx, ".initrd", &_) ||
+ find_section(&pe_ctx, ".cmdline", &_)) {
+ pr_info("Not a UKI. Missing .linux, .initrd, or .cmdline\n");
+ return ret;
+ }
+
+
+ pr_info("It's a UKI\n");
+ return 0;
+}
+
+static void *uki_load(struct kimage *image, char *kernel,
+ unsigned long kernel_len, char *initrd,
+ unsigned long initrd_len, char *cmdline,
+ unsigned long cmdline_len)
+{
+ struct pefile_context pe_ctx;
+ int r = pefile_parse_binary(kernel, kernel_len, &pe_ctx);
+
+ if (r)
+ return ERR_PTR(r);
+
+ pr_debug("pefile_parse_binary return %d, number of sections: %d\n",
+ r, pe_ctx.n_sections);
+
+ const struct section_header *sec_linux, *sec_initrd, *sec_cmdline;
+ int r_linux = find_section(&pe_ctx, ".linux", &sec_linux);
+ int r_initrd = find_section(&pe_ctx, ".initrd", &sec_initrd);
+ int r_cmdline = find_section(&pe_ctx, ".cmdline", &sec_cmdline);
+
+ if (r_linux || r_initrd || r_cmdline)
+ return ERR_PTR(-EINVAL);
+
+ void *ret = kexec_bzImage64_ops.load(
+ image,
+ kernel + sec_linux->data_addr,
+ sec_linux->raw_data_size,
+ kernel + sec_initrd->data_addr,
+ sec_initrd->raw_data_size,
+ kernel + sec_cmdline->data_addr,
+ sec_cmdline->raw_data_size
+ );
+
+ if (IS_ERR(ret))
+ pr_warn("bzImage64_load error\n");
+
+ return ret;
+}
+
+static int uki_cleanup(void *loader_data)
+{
+ return kexec_bzImage64_ops.cleanup(loader_data);
+}
+
+const struct kexec_file_ops kexec_uki_ops = {
+ .probe = uki_probe,
+ .load = uki_load,
+ .cleanup = uki_cleanup,
+#ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
+ .verify_sig = kexec_kernel_verify_pe_sig,
+#endif
+};
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 1a3e2c05a8a5..072f5aac52b9 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -25,6 +25,7 @@
#include <asm/io_apic.h>
#include <asm/debugreg.h>
#include <asm/kexec-bzimage64.h>
+#include <asm/kexec-uki.h>
#include <asm/setup.h>
#include <asm/set_memory.h>
#include <asm/cpu.h>
@@ -81,6 +82,7 @@ static int map_acpi_tables(struct x86_mapping_info *info, pgd_t *level4p) { retu
#ifdef CONFIG_KEXEC_FILE
const struct kexec_file_ops * const kexec_file_loaders[] = {
&kexec_bzImage64_ops,
+ &kexec_uki_ops,
NULL
};
#endif
diff --git a/arch/x86/kernel/parse_pefile.c b/arch/x86/kernel/parse_pefile.c
new file mode 100644
index 000000000000..7737c94a1848
--- /dev/null
+++ b/arch/x86/kernel/parse_pefile.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Parse a PE binary
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2023 Jan Hendrik Farr
+ *
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#include <asm/parse_pefile.h>
+#include <linux/err.h>
+
+#define pr_fmt(fmt) "parse_pefile: " fmt
+#include <linux/module.h>
+/*
+ * Parse a PE binary.
+ */
+int pefile_parse_binary(const void *pebuf, unsigned int pelen,
+ struct pefile_context *ctx)
+{
+ const struct mz_hdr *mz = pebuf;
+ const struct pe_hdr *pe;
+ const struct pe32_opt_hdr *pe32;
+ const struct pe32plus_opt_hdr *pe64;
+ const struct data_directory *ddir;
+ const struct data_dirent *dde;
+ const struct section_header *secs, *sec;
+ size_t cursor, datalen = pelen;
+
+
+#define chkaddr(base, x, s) \
+ do { \
+ if ((x) < base || (s) >= datalen || (x) > datalen - (s)) \
+ return -ELIBBAD; \
+ } while (0)
+
+ chkaddr(0, 0, sizeof(*mz));
+ if (mz->magic != MZ_MAGIC)
+ return -ELIBBAD;
+ cursor = sizeof(*mz);
+
+ chkaddr(cursor, mz->peaddr, sizeof(*pe));
+ pe = pebuf + mz->peaddr;
+ if (pe->magic != PE_MAGIC)
+ return -ELIBBAD;
+ cursor = mz->peaddr + sizeof(*pe);
+
+ chkaddr(0, cursor, sizeof(pe32->magic));
+ pe32 = pebuf + cursor;
+ pe64 = pebuf + cursor;
+
+ switch (pe32->magic) {
+ case PE_OPT_MAGIC_PE32:
+ chkaddr(0, cursor, sizeof(*pe32));
+ ctx->image_checksum_offset =
+ (unsigned long)&pe32->csum - (unsigned long)pebuf;
+ ctx->header_size = pe32->header_size;
+ cursor += sizeof(*pe32);
+ ctx->n_data_dirents = pe32->data_dirs;
+ break;
+
+ case PE_OPT_MAGIC_PE32PLUS:
+ chkaddr(0, cursor, sizeof(*pe64));
+ ctx->image_checksum_offset =
+ (unsigned long)&pe64->csum - (unsigned long)pebuf;
+ ctx->header_size = pe64->header_size;
+ cursor += sizeof(*pe64);
+ ctx->n_data_dirents = pe64->data_dirs;
+ break;
+
+ default:
+ pr_warn("Unknown PEOPT magic = %04hx\n", pe32->magic);
+ return -ELIBBAD;
+ }
+
+ pr_debug("checksum @ %x\n", ctx->image_checksum_offset);
+ pr_debug("header size = %x\n", ctx->header_size);
+
+ if (cursor >= ctx->header_size || ctx->header_size >= datalen)
+ return -ELIBBAD;
+
+ if (ctx->n_data_dirents > (ctx->header_size - cursor) / sizeof(*dde))
+ return -ELIBBAD;
+
+ ddir = pebuf + cursor;
+ cursor += sizeof(*dde) * ctx->n_data_dirents;
+
+ ctx->cert_dirent_offset =
+ (unsigned long)&ddir->certs - (unsigned long)pebuf;
+ ctx->certs_size = ddir->certs.size;
+
+ if (ddir->certs.virtual_address && ddir->certs.size) {
+
+ chkaddr(ctx->header_size, ddir->certs.virtual_address,
+ ddir->certs.size);
+ ctx->sig_offset = ddir->certs.virtual_address;
+ ctx->sig_len = ddir->certs.size;
+ pr_debug("cert = %x @%x [%*ph]\n",
+ ctx->sig_len, ctx->sig_offset,
+ ctx->sig_len, pebuf + ctx->sig_offset);
+
+ }
+
+ ctx->n_sections = pe->sections;
+ if (ctx->n_sections > (ctx->header_size - cursor) / sizeof(*sec))
+ return -ELIBBAD;
+ ctx->secs = secs = pebuf + cursor;
+
+ return 0;
+}
diff --git a/crypto/asymmetric_keys/mscode_parser.c b/crypto/asymmetric_keys/mscode_parser.c
index 839591ad21ac..063b348bb4c3 100644
--- a/crypto/asymmetric_keys/mscode_parser.c
+++ b/crypto/asymmetric_keys/mscode_parser.c
@@ -11,7 +11,7 @@
#include <linux/err.h>
#include <linux/oid_registry.h>
#include <crypto/pkcs7.h>
-#include "verify_pefile.h"
+#include <asm/parse_pefile.h>
#include "mscode.asn1.h"
/*
diff --git a/crypto/asymmetric_keys/verify_pefile.c b/crypto/asymmetric_keys/verify_pefile.c
index f440767bd727..fbb319094c0a 100644
--- a/crypto/asymmetric_keys/verify_pefile.c
+++ b/crypto/asymmetric_keys/verify_pefile.c
@@ -14,106 +14,9 @@
#include <linux/asn1.h>
#include <linux/verification.h>
#include <crypto/hash.h>
+#include <asm/parse_pefile.h>
#include "verify_pefile.h"
-/*
- * Parse a PE binary.
- */
-static int pefile_parse_binary(const void *pebuf, unsigned int pelen,
- struct pefile_context *ctx)
-{
- const struct mz_hdr *mz = pebuf;
- const struct pe_hdr *pe;
- const struct pe32_opt_hdr *pe32;
- const struct pe32plus_opt_hdr *pe64;
- const struct data_directory *ddir;
- const struct data_dirent *dde;
- const struct section_header *secs, *sec;
- size_t cursor, datalen = pelen;
-
- kenter("");
-
-#define chkaddr(base, x, s) \
- do { \
- if ((x) < base || (s) >= datalen || (x) > datalen - (s)) \
- return -ELIBBAD; \
- } while (0)
-
- chkaddr(0, 0, sizeof(*mz));
- if (mz->magic != MZ_MAGIC)
- return -ELIBBAD;
- cursor = sizeof(*mz);
-
- chkaddr(cursor, mz->peaddr, sizeof(*pe));
- pe = pebuf + mz->peaddr;
- if (pe->magic != PE_MAGIC)
- return -ELIBBAD;
- cursor = mz->peaddr + sizeof(*pe);
-
- chkaddr(0, cursor, sizeof(pe32->magic));
- pe32 = pebuf + cursor;
- pe64 = pebuf + cursor;
-
- switch (pe32->magic) {
- case PE_OPT_MAGIC_PE32:
- chkaddr(0, cursor, sizeof(*pe32));
- ctx->image_checksum_offset =
- (unsigned long)&pe32->csum - (unsigned long)pebuf;
- ctx->header_size = pe32->header_size;
- cursor += sizeof(*pe32);
- ctx->n_data_dirents = pe32->data_dirs;
- break;
-
- case PE_OPT_MAGIC_PE32PLUS:
- chkaddr(0, cursor, sizeof(*pe64));
- ctx->image_checksum_offset =
- (unsigned long)&pe64->csum - (unsigned long)pebuf;
- ctx->header_size = pe64->header_size;
- cursor += sizeof(*pe64);
- ctx->n_data_dirents = pe64->data_dirs;
- break;
-
- default:
- pr_warn("Unknown PEOPT magic = %04hx\n", pe32->magic);
- return -ELIBBAD;
- }
-
- pr_debug("checksum @ %x\n", ctx->image_checksum_offset);
- pr_debug("header size = %x\n", ctx->header_size);
-
- if (cursor >= ctx->header_size || ctx->header_size >= datalen)
- return -ELIBBAD;
-
- if (ctx->n_data_dirents > (ctx->header_size - cursor) / sizeof(*dde))
- return -ELIBBAD;
-
- ddir = pebuf + cursor;
- cursor += sizeof(*dde) * ctx->n_data_dirents;
-
- ctx->cert_dirent_offset =
- (unsigned long)&ddir->certs - (unsigned long)pebuf;
- ctx->certs_size = ddir->certs.size;
-
- if (!ddir->certs.virtual_address || !ddir->certs.size) {
- pr_warn("Unsigned PE binary\n");
- return -ENODATA;
- }
-
- chkaddr(ctx->header_size, ddir->certs.virtual_address,
- ddir->certs.size);
- ctx->sig_offset = ddir->certs.virtual_address;
- ctx->sig_len = ddir->certs.size;
- pr_debug("cert = %x @%x [%*ph]\n",
- ctx->sig_len, ctx->sig_offset,
- ctx->sig_len, pebuf + ctx->sig_offset);
-
- ctx->n_sections = pe->sections;
- if (ctx->n_sections > (ctx->header_size - cursor) / sizeof(*sec))
- return -ELIBBAD;
- ctx->secs = secs = pebuf + cursor;
-
- return 0;
-}
/*
* Check and strip the PE wrapper from around the signature and check that the
@@ -431,6 +334,13 @@ int verify_pefile_signature(const void *pebuf, unsigned pelen,
if (ret < 0)
return ret;
+ const struct data_dirent *certs = pebuf + ctx.cert_dirent_offset;
+
+ if (!certs->virtual_address || !certs->size) {
+ pr_warn("Unsigned PE binary\n");
+ return -ENODATA;
+ }
+
ret = pefile_strip_sig_wrapper(pebuf, &ctx);
if (ret < 0)
return ret;
@@ -439,8 +349,10 @@ int verify_pefile_signature(const void *pebuf, unsigned pelen,
pebuf + ctx.sig_offset, ctx.sig_len,
trusted_keys, usage,
mscode_parse, &ctx);
- if (ret < 0)
+ if (ret < 0) {
+ pr_warn("invalid PE file signature\n");
goto error;
+ }
pr_debug("Digest: %u [%*ph]\n",
ctx.digest_len, ctx.digest_len, ctx.digest);
diff --git a/crypto/asymmetric_keys/verify_pefile.h b/crypto/asymmetric_keys/verify_pefile.h
index e1628e100cde..5ab2f9a5b2ef 100644
--- a/crypto/asymmetric_keys/verify_pefile.h
+++ b/crypto/asymmetric_keys/verify_pefile.h
@@ -8,22 +8,6 @@
#include <crypto/pkcs7.h>
#include <crypto/hash_info.h>
-struct pefile_context {
- unsigned header_size;
- unsigned image_checksum_offset;
- unsigned cert_dirent_offset;
- unsigned n_data_dirents;
- unsigned n_sections;
- unsigned certs_size;
- unsigned sig_offset;
- unsigned sig_len;
- const struct section_header *secs;
-
- /* PKCS#7 MS Individual Code Signing content */
- const void *digest; /* Digest */
- unsigned digest_len; /* Digest length */
- const char *digest_algo; /* Digest algorithm */
-};
#define kenter(FMT, ...) \
pr_devel("==> %s("FMT")\n", __func__, ##__VA_ARGS__)
--
2.40.1
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