diff options
Diffstat (limited to 'debian/patches/features/all/db-mok-keyring')
5 files changed, 335 insertions, 0 deletions
diff --git a/debian/patches/features/all/db-mok-keyring/0001-MODSIGN-do-not-load-mok-when-secure-boot-disabled.patch b/debian/patches/features/all/db-mok-keyring/0001-MODSIGN-do-not-load-mok-when-secure-boot-disabled.patch new file mode 100644 index 000000000..5d4ec82f0 --- /dev/null +++ b/debian/patches/features/all/db-mok-keyring/0001-MODSIGN-do-not-load-mok-when-secure-boot-disabled.patch @@ -0,0 +1,40 @@ +From: "Lee, Chun-Yi" <joeyli.kernel@gmail.com> +Date: Tue, 13 Mar 2018 18:37:59 +0800 +Subject: [PATCH 1/5] MODSIGN: do not load mok when secure boot disabled +Origin: https://lore.kernel.org/patchwork/patch/933173/ + +The mok can not be trusted when the secure boot is disabled. Which +means that the kernel embedded certificate is the only trusted key. + +Due to db/dbx are authenticated variables, they needs manufacturer's +KEK for update. So db/dbx are secure when secureboot disabled. + +Cc: David Howells <dhowells@redhat.com> +Cc: Josh Boyer <jwboyer@fedoraproject.org> +Cc: James Bottomley <James.Bottomley@HansenPartnership.com> +Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com> +[Rebased by Luca Boccassi] +[bwh: Forward-ported to 5.5.9: + - get_cert_list() takes a pointer to status and returns the cert list + - Adjust filename] +[Salvatore Bonaccorso: Forward-ported to 5.10: Refresh for changes in +38a1f03aa240 ("integrity: Move import of MokListRT certs to a separate +routine"). Refresh in context for change in ebd9c2ae369a ("integrity: Load mokx +variables into the blacklist keyring")] +--- + security/integrity/platform_certs/load_uefi.c | 26 +++++++++++++++----------- + 1 file changed, 15 insertions(+), 11 deletions(-) + +--- a/security/integrity/platform_certs/load_uefi.c ++++ b/security/integrity/platform_certs/load_uefi.c +@@ -176,6 +176,10 @@ static int __init load_uefi_certs(void) + kfree(dbx); + } + ++ /* the MOK can not be trusted when secure boot is disabled */ ++ if (!efi_enabled(EFI_SECURE_BOOT)) ++ return 0; ++ + mokx = get_cert_list(L"MokListXRT", &mok_var, &mokxsize, &status); + if (!mokx) { + if (status == EFI_NOT_FOUND) diff --git a/debian/patches/features/all/db-mok-keyring/0003-MODSIGN-checking-the-blacklisted-hash-before-loading-a-kernel-module.patch b/debian/patches/features/all/db-mok-keyring/0003-MODSIGN-checking-the-blacklisted-hash-before-loading-a-kernel-module.patch new file mode 100644 index 000000000..a7ec5ccb5 --- /dev/null +++ b/debian/patches/features/all/db-mok-keyring/0003-MODSIGN-checking-the-blacklisted-hash-before-loading-a-kernel-module.patch @@ -0,0 +1,117 @@ +From: "Lee, Chun-Yi" <joeyli.kernel@gmail.com> +Date: Tue, 13 Mar 2018 18:38:02 +0800 +Subject: [PATCH 3/4] MODSIGN: checking the blacklisted hash before loading a + kernel module +Origin: https://lore.kernel.org/patchwork/patch/933175/ + +This patch adds the logic for checking the kernel module's hash +base on blacklist. The hash must be generated by sha256 and enrolled +to dbx/mokx. + +For example: + sha256sum sample.ko + mokutil --mokx --import-hash $HASH_RESULT + +Whether the signature on ko file is stripped or not, the hash can be +compared by kernel. + +Cc: David Howells <dhowells@redhat.com> +Cc: Josh Boyer <jwboyer@fedoraproject.org> +Cc: James Bottomley <James.Bottomley@HansenPartnership.com> +Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com> +[Rebased by Luca Boccassi] +--- + kernel/module_signing.c | 59 +++++++++++++++++++++++++++++++++++++++-- + 1 file changed, 57 insertions(+), 2 deletions(-) + +--- a/kernel/module_signing.c ++++ b/kernel/module_signing.c +@@ -12,15 +12,62 @@ + #include <linux/string.h> + #include <linux/verification.h> + #include <crypto/public_key.h> ++#include <crypto/hash.h> ++#include <keys/system_keyring.h> + #include "module-internal.h" + ++static int mod_is_hash_blacklisted(const void *mod, size_t verifylen) ++{ ++ struct crypto_shash *tfm; ++ struct shash_desc *desc; ++ size_t digest_size, desc_size; ++ u8 *digest; ++ int ret = 0; ++ ++ tfm = crypto_alloc_shash("sha256", 0, 0); ++ if (IS_ERR(tfm)) ++ goto error_return; ++ ++ desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); ++ digest_size = crypto_shash_digestsize(tfm); ++ digest = kzalloc(digest_size + desc_size, GFP_KERNEL); ++ if (!digest) { ++ pr_err("digest memory buffer allocate fail\n"); ++ ret = -ENOMEM; ++ goto error_digest; ++ } ++ desc = (void *)digest + digest_size; ++ desc->tfm = tfm; ++ ret = crypto_shash_init(desc); ++ if (ret < 0) ++ goto error_shash; ++ ++ ret = crypto_shash_finup(desc, mod, verifylen, digest); ++ if (ret < 0) ++ goto error_shash; ++ ++ pr_debug("%ld digest: %*phN\n", verifylen, (int) digest_size, digest); ++ ++ ret = is_hash_blacklisted(digest, digest_size, "bin"); ++ if (ret == -EKEYREJECTED) ++ pr_err("Module hash %*phN is blacklisted\n", ++ (int) digest_size, digest); ++ ++error_shash: ++ kfree(digest); ++error_digest: ++ crypto_free_shash(tfm); ++error_return: ++ return ret; ++} ++ + /* + * Verify the signature on a module. + */ + int mod_verify_sig(const void *mod, struct load_info *info) + { + struct module_signature ms; +- size_t sig_len, modlen = info->len; ++ size_t sig_len, modlen = info->len, wholelen; + int ret; + + pr_devel("==>%s(,%zu)\n", __func__, modlen); +@@ -28,6 +75,7 @@ int mod_verify_sig(const void *mod, stru + if (modlen <= sizeof(ms)) + return -EBADMSG; + ++ wholelen = modlen + sizeof(MODULE_SIG_STRING) - 1; + memcpy(&ms, mod + (modlen - sizeof(ms)), sizeof(ms)); + + ret = mod_check_sig(&ms, modlen, "module"); +@@ -38,8 +86,15 @@ int mod_verify_sig(const void *mod, stru + modlen -= sig_len + sizeof(ms); + info->len = modlen; + +- return verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len, ++ ret = verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len, + VERIFY_USE_SECONDARY_KEYRING, + VERIFYING_MODULE_SIGNATURE, + NULL, NULL); ++ pr_devel("verify_pkcs7_signature() = %d\n", ret); ++ ++ /* checking hash of module is in blacklist */ ++ if (!ret) ++ ret = mod_is_hash_blacklisted(mod, wholelen); ++ ++ return ret; + } diff --git a/debian/patches/features/all/db-mok-keyring/0004-MODSIGN-check-the-attributes-of-db-and-mok.patch b/debian/patches/features/all/db-mok-keyring/0004-MODSIGN-check-the-attributes-of-db-and-mok.patch new file mode 100644 index 000000000..530885944 --- /dev/null +++ b/debian/patches/features/all/db-mok-keyring/0004-MODSIGN-check-the-attributes-of-db-and-mok.patch @@ -0,0 +1,113 @@ +From: "Lee, Chun-Yi" <joeyli.kernel@gmail.com> +Date: Tue, 13 Mar 2018 18:38:03 +0800 +Subject: [PATCH 4/4] MODSIGN: check the attributes of db and mok +Origin: https://lore.kernel.org/patchwork/patch/933176/ + +That's better for checking the attributes of db and mok variables +before loading certificates to kernel keyring. + +For db and dbx, both of them are authenticated variables. Which +means that they can only be modified by manufacturer's key. So +the kernel should checks EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS +attribute before we trust it. + +For mok-rt and mokx-rt, both of them are created by shim boot loader +to forward the mok/mokx content to runtime. They must be runtime-volatile +variables. So kernel should checks that the attributes map did not set +EFI_VARIABLE_NON_VOLATILE bit before we trust it. + +Cc: David Howells <dhowells@redhat.com> +Cc: Josh Boyer <jwboyer@fedoraproject.org> +Cc: James Bottomley <James.Bottomley@HansenPartnership.com> +Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com> +[Rebased by Luca Boccassi] +[bwh: Forward-ported to 5.5.9: + - get_cert_list() takes a pointer to status and returns the cert list + - Adjust filename, context] +[bwh: Forward-ported to 5.10: MokListRT and MokListXRT are now both + loaded through a single code path.] +--- + security/integrity/platform_certs/load_uefi.c | 27 ++++++++++++++----- + 1 file changed, 21 insertions(+), 6 deletions(-) + +--- a/security/integrity/platform_certs/load_uefi.c ++++ b/security/integrity/platform_certs/load_uefi.c +@@ -35,11 +35,13 @@ static __init bool uefi_check_ignore_db( + * Get a certificate list blob from the named EFI variable. + */ + static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid, +- unsigned long *size, efi_status_t *status) ++ unsigned long *size, efi_status_t *status, ++ u32 pos_attr, u32 neg_attr) + { + unsigned long lsize = 4; + unsigned long tmpdb[4]; + void *db; ++ u32 attr = 0; + + *status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb); + if (*status == EFI_NOT_FOUND) +@@ -54,13 +56,22 @@ static __init void *get_cert_list(efi_ch + if (!db) + return NULL; + +- *status = efi.get_variable(name, guid, NULL, &lsize, db); ++ *status = efi.get_variable(name, guid, &attr, &lsize, db); + if (*status != EFI_SUCCESS) { + kfree(db); + pr_err("Error reading db var: 0x%lx\n", *status); + return NULL; + } + ++ /* must have positive attributes and no negative attributes */ ++ if ((pos_attr && !(attr & pos_attr)) || ++ (neg_attr && (attr & neg_attr))) { ++ kfree(db); ++ pr_err("Error reading db var attributes: 0x%016x\n", attr); ++ *status = EFI_SECURITY_VIOLATION; ++ return NULL; ++ } ++ + *size = lsize; + return db; + } +@@ -106,7 +117,8 @@ static int __init load_moklist_certs(voi + /* Get MokListRT. It might not exist, so it isn't an error + * if we can't get it. + */ +- mok = get_cert_list(L"MokListRT", &mok_var, &moksize, &status); ++ mok = get_cert_list(L"MokListRT", &mok_var, &moksize, &status, ++ 0, EFI_VARIABLE_NON_VOLATILE); + if (mok) { + rc = parse_efi_signature_list("UEFI:MokListRT", + mok, moksize, get_handler_for_db); +@@ -145,7 +157,8 @@ static int __init load_uefi_certs(void) + * if we can't get them. + */ + if (!uefi_check_ignore_db()) { +- db = get_cert_list(L"db", &secure_var, &dbsize, &status); ++ db = get_cert_list(L"db", &secure_var, &dbsize, &status, ++ EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS, 0); + if (!db) { + if (status == EFI_NOT_FOUND) + pr_debug("MODSIGN: db variable wasn't found\n"); +@@ -161,7 +174,8 @@ static int __init load_uefi_certs(void) + } + } + +- dbx = get_cert_list(L"dbx", &secure_var, &dbxsize, &status); ++ dbx = get_cert_list(L"dbx", &secure_var, &dbxsize, &status, ++ EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS, 0); + if (!dbx) { + if (status == EFI_NOT_FOUND) + pr_debug("dbx variable wasn't found\n"); +@@ -180,7 +194,8 @@ static int __init load_uefi_certs(void) + if (!efi_enabled(EFI_SECURE_BOOT)) + return 0; + +- mokx = get_cert_list(L"MokListXRT", &mok_var, &mokxsize, &status); ++ mokx = get_cert_list(L"MokListXRT", &mok_var, &mokxsize, &status, ++ 0, EFI_VARIABLE_NON_VOLATILE); + if (!mokx) { + if (status == EFI_NOT_FOUND) + pr_debug("mokx variable wasn't found\n"); diff --git a/debian/patches/features/all/db-mok-keyring/KEYS-Make-use-of-platform-keyring-for-module-signature.patch b/debian/patches/features/all/db-mok-keyring/KEYS-Make-use-of-platform-keyring-for-module-signature.patch new file mode 100644 index 000000000..f00bf3d24 --- /dev/null +++ b/debian/patches/features/all/db-mok-keyring/KEYS-Make-use-of-platform-keyring-for-module-signature.patch @@ -0,0 +1,37 @@ +From: Robert Holmes <robeholmes@gmail.com> +Date: Tue, 23 Apr 2019 07:39:29 +0000 +Subject: [PATCH] KEYS: Make use of platform keyring for module signature + verify +Bug-Debian: https://bugs.debian.org/935945 +Origin: https://src.fedoraproject.org/rpms/kernel/raw/master/f/KEYS-Make-use-of-platform-keyring-for-module-signature.patch + +This patch completes commit 278311e417be ("kexec, KEYS: Make use of +platform keyring for signature verify") which, while adding the +platform keyring for bzImage verification, neglected to also add +this keyring for module verification. + +As such, kernel modules signed with keys from the MokList variable +were not successfully verified. + +Signed-off-by: Robert Holmes <robeholmes@gmail.com> +Signed-off-by: Jeremy Cline <jcline@redhat.com> +--- + kernel/module_signing.c | 16 ++++++++++++---- + 1 file changed, 12 insertions(+), 4 deletions(-) + +--- a/kernel/module_signing.c ++++ b/kernel/module_signing.c +@@ -135,6 +135,13 @@ int mod_verify_sig(const void *mod, stru + VERIFYING_MODULE_SIGNATURE, + NULL, NULL); + pr_devel("verify_pkcs7_signature() = %d\n", ret); ++ if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) { ++ ret = verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len, ++ VERIFY_USE_PLATFORM_KEYRING, ++ VERIFYING_MODULE_SIGNATURE, ++ NULL, NULL); ++ pr_devel("verify_pkcs7_signature() = %d\n", ret); ++ } + + /* checking hash of module is in blacklist */ + if (!ret) diff --git a/debian/patches/features/all/db-mok-keyring/modsign-make-shash-allocation-failure-fatal.patch b/debian/patches/features/all/db-mok-keyring/modsign-make-shash-allocation-failure-fatal.patch new file mode 100644 index 000000000..2ae3ddde4 --- /dev/null +++ b/debian/patches/features/all/db-mok-keyring/modsign-make-shash-allocation-failure-fatal.patch @@ -0,0 +1,28 @@ +From: Ben Hutchings <ben@decadent.org.uk> +Date: Sun, 05 May 2019 13:45:06 +0100 +Subject: MODSIGN: Make shash allocation failure fatal + +mod_is_hash_blacklisted() currently returns 0 (suceess) if +crypto_alloc_shash() fails. This should instead be a fatal error, +so unwrap and pass up the error code. + +Signed-off-by: Ben Hutchings <ben@decadent.org.uk> +--- +--- a/kernel/module_signing.c ++++ b/kernel/module_signing.c +@@ -51,11 +51,13 @@ static int mod_is_hash_blacklisted(const + struct shash_desc *desc; + size_t digest_size, desc_size; + u8 *digest; +- int ret = 0; ++ int ret; + + tfm = crypto_alloc_shash("sha256", 0, 0); +- if (IS_ERR(tfm)) ++ if (IS_ERR(tfm)) { ++ ret = PTR_ERR(tfm); + goto error_return; ++ } + + desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); + digest_size = crypto_shash_digestsize(tfm); |