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spf=pass smtp.mailfrom=linux-audit-bounces@redhat.com Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-375-ubmSRvNWOzG6kDrPBrsqbw-1; Wed, 29 Jul 2020 22:30:42 -0400 X-MC-Unique: ubmSRvNWOzG6kDrPBrsqbw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A92578064AE; Thu, 30 Jul 2020 02:30:38 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 918417010B; Thu, 30 Jul 2020 02:30:38 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 705B095A80; Thu, 30 Jul 2020 02:30:38 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 06U0VXGl010300 for ; Wed, 29 Jul 2020 20:31:33 -0400 Received: by smtp.corp.redhat.com (Postfix) id 655ED110D5A1; Thu, 30 Jul 2020 00:31:33 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast02.extmail.prod.ext.rdu2.redhat.com [10.11.55.18]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4C0B0110D59D for ; Thu, 30 Jul 2020 00:31:29 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 20E688007C8 for ; Thu, 30 Jul 2020 00:31:29 +0000 (UTC) Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by relay.mimecast.com with ESMTP id us-mta-156-kHpyjhDOMVuv9tumGu9Qgw-1; Wed, 29 Jul 2020 20:31:23 -0400 X-MC-Unique: kHpyjhDOMVuv9tumGu9Qgw-1 Received: from dede-linux-virt.corp.microsoft.com (unknown [131.107.160.54]) by linux.microsoft.com (Postfix) with ESMTPSA id 9FA4A20B4911; Wed, 29 Jul 2020 17:31:20 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 9FA4A20B4911 From: Deven Bowers To: agk@redhat.com, axboe@kernel.dk, snitzer@redhat.com, jmorris@namei.org, serge@hallyn.com, zohar@linux.ibm.com, viro@zeniv.linux.org.uk, paul@paul-moore.com, eparis@redhat.com, jannh@google.com, dm-devel@redhat.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-audit@redhat.com Subject: [RFC PATCH v6 07/11] ipe: add property for signed dmverity volumes Date: Wed, 29 Jul 2020 17:31:09 -0700 Message-Id: <20200730003113.2561644-8-deven.desai@linux.microsoft.com> In-Reply-To: <20200730003113.2561644-1-deven.desai@linux.microsoft.com> References: <20200730003113.2561644-1-deven.desai@linux.microsoft.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-MIME-Autoconverted: from quoted-printable to 8bit by lists01.pubmisc.prod.ext.phx2.redhat.com id 06U0VXGl010300 X-loop: linux-audit@redhat.com X-Mailman-Approved-At: Wed, 29 Jul 2020 22:28:53 -0400 Cc: sashal@kernel.org, pasha.tatashin@soleen.com, mdsakib@microsoft.com, corbet@lwn.net, linux-kernel@vger.kernel.org, nramas@linux.microsoft.com, tyhicks@linux.microsoft.com, jaskarankhurana@linux.microsoft.com X-BeenThere: linux-audit@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: Linux Audit Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-audit-bounces@redhat.com Errors-To: linux-audit-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Allow IPE to leverage the stacked security blob infrastructure, and enlighten IPE to the block_device security blob. This allows IPE to have a property to express rules around a device-mapper verity volume whose root-hash has been signed, and the signature has been verified against the system keyring. This is property is also added in this patch. Signed-off-by: Deven Bowers --- security/ipe/Kconfig | 2 +- security/ipe/Makefile | 1 + security/ipe/ipe-blobs.c | 84 ++++++++++++++++++++ security/ipe/ipe-blobs.h | 18 +++++ security/ipe/ipe-engine.c | 4 + security/ipe/ipe-engine.h | 9 +++ security/ipe/ipe-hooks.c | 1 + security/ipe/ipe-hooks.h | 7 ++ security/ipe/ipe.c | 18 +++++ security/ipe/ipe.h | 2 + security/ipe/properties/Kconfig | 10 +++ security/ipe/properties/Makefile | 1 + security/ipe/properties/dmverity-signature.c | 82 +++++++++++++++++++ security/ipe/properties/prop-entry.h | 9 +++ security/ipe/utility.h | 10 +++ 15 files changed, 257 insertions(+), 1 deletion(-) create mode 100644 security/ipe/ipe-blobs.c create mode 100644 security/ipe/ipe-blobs.h create mode 100644 security/ipe/properties/dmverity-signature.c diff --git a/security/ipe/Kconfig b/security/ipe/Kconfig index 469ef78c2f4f..11b50ef9abca 100644 --- a/security/ipe/Kconfig +++ b/security/ipe/Kconfig @@ -5,7 +5,7 @@ menuconfig SECURITY_IPE bool "Integrity Policy Enforcement (IPE)" - depends on SECURITY && AUDIT + depends on SECURITY && AUDIT && BLOCK select SYSTEM_DATA_VERIFICATION select SECURITYFS select CRYPTO_SHA1 diff --git a/security/ipe/Makefile b/security/ipe/Makefile index 7e98982c5035..98a2245b6956 100644 --- a/security/ipe/Makefile +++ b/security/ipe/Makefile @@ -24,6 +24,7 @@ obj-$(CONFIG_SECURITY_IPE) += \ ipe-property.o \ ipe-hooks.o \ ipe-secfs.o \ + ipe-blobs.o \ clean-files := ipe-bp.c diff --git a/security/ipe/ipe-blobs.c b/security/ipe/ipe-blobs.c new file mode 100644 index 000000000000..041d7d47b723 --- /dev/null +++ b/security/ipe/ipe-blobs.c @@ -0,0 +1,84 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) Microsoft Corporation. All rights reserved. + */ + +#include "ipe.h" +#include "ipe-engine.h" +#include "ipe-blobs.h" + +#include +#include +#include + +/** + * ipe_bdev_alloc_security: Performs the initialization of IPE's security blob. + * @bdev: The block device to source the security blob from. + * + * The allocation is performed earlier by the LSM infrastructure, + * (on behalf of all LSMs) in lsm_alloc_bdev. At the moment, IPE uses + * this time to zero out the region of memory reserved for IPE. + * + * Return: + * 0 - OK + */ +int ipe_bdev_alloc_security(struct block_device *bdev) +{ + struct ipe_bdev_blob *bdev_sec = ipe_bdev(bdev); + + memset(bdev_sec, 0x0, sizeof(*bdev_sec)); + + return 0; +} + +/** + * ipe_bdev_free_security: Frees all fields of IPE's block dev security blob. + * @bdev: The block device to source the security blob from. + * + * The deallocation of the blob itself is performed later by the LSM + * infrastructure, (on behalf of all LSMs) in lsm_free_bdev. + * + * Pointers allocated by the bdev_setsecurity hook and alloc_security + * hook need to be deallocated here. + */ +void ipe_bdev_free_security(struct block_device *bdev) +{ + struct ipe_bdev_blob *bdev_sec = ipe_bdev(bdev); + + kfree(bdev_sec->dmverity_rh_sig); + + memset(bdev_sec, 0x0, sizeof(*bdev_sec)); +} + +/** + * ipe_bdev_setsecurity: Sets the a certain field of a block device security + * blob, based on @key. + * @bdev: The block device to source the security blob from. + * @key: The key representing the information to be stored. + * @value: The value to be stored. + * @len: The length of @value. + * + * As block-devices are a generic implementation across specific stacks, + * this allows information to be stored from various stacks. + * + * Return: + * 0 - OK + * !0 - Error + */ +int ipe_bdev_setsecurity(struct block_device *bdev, const char *key, + const void *value, size_t len) +{ + struct ipe_bdev_blob *bdev_sec = ipe_bdev(bdev); + + if (!strcmp(key, DM_VERITY_SIGNATURE_SEC_NAME)) { + bdev_sec->dmverity_rh_sig = kmemdup(value, len, GFP_KERNEL); + if (!bdev_sec->dmverity_rh_sig) + return -ENOMEM; + + bdev_sec->dmv_rh_sig_len = len; + + return 0; + } + + return -ENOSYS; +} diff --git a/security/ipe/ipe-blobs.h b/security/ipe/ipe-blobs.h new file mode 100644 index 000000000000..7561f4cef558 --- /dev/null +++ b/security/ipe/ipe-blobs.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) Microsoft Corporation. All rights reserved. + */ +#include +#include + +#include "ipe.h" + +#ifndef IPE_BLOB_H +#define IPE_BLOB_H + +static inline struct ipe_bdev_blob *ipe_bdev(struct block_device *bdev) +{ + return bdev->security + ipe_blobs.lbs_bdev; +} + +#endif /* IPE_BLOB_H */ diff --git a/security/ipe/ipe-engine.c b/security/ipe/ipe-engine.c index 0291ced99d64..043faf64ceef 100644 --- a/security/ipe/ipe-engine.c +++ b/security/ipe/ipe-engine.c @@ -10,6 +10,7 @@ #include "ipe-engine.h" #include "ipe-audit.h" #include "ipe-pin.h" +#include "ipe-blobs.h" #include "utility.h" #include @@ -112,6 +113,9 @@ static struct ipe_engine_ctx *build_ctx(const struct file *file, local->op = op; local->hook = hook; + if (has_bdev(file)) + local->sec_bdev = ipe_bdev(bdev(file)); + return local; } diff --git a/security/ipe/ipe-engine.h b/security/ipe/ipe-engine.h index d9a95674e70d..038c39a8973e 100644 --- a/security/ipe/ipe-engine.h +++ b/security/ipe/ipe-engine.h @@ -3,20 +3,29 @@ * Copyright (C) Microsoft Corporation. All rights reserved. */ +#include "ipe.h" #include "ipe-hooks.h" #include #include #include +#include + #ifndef IPE_ENGINE_H #define IPE_ENGINE_H +struct ipe_bdev_blob { + u8 *dmverity_rh_sig; + size_t dmv_rh_sig_len; +}; + struct ipe_engine_ctx { enum ipe_op op; enum ipe_hook hook; const struct file *file; const char *audit_pathname; + const struct ipe_bdev_blob *sec_bdev; }; struct ipe_prop_cache { diff --git a/security/ipe/ipe-hooks.c b/security/ipe/ipe-hooks.c index 45efe022be04..18ab2dcd74d1 100644 --- a/security/ipe/ipe-hooks.c +++ b/security/ipe/ipe-hooks.c @@ -15,6 +15,7 @@ #include #include #include +#include /** * ipe_on_exec: LSM hook called on the exec family of system calls. diff --git a/security/ipe/ipe-hooks.h b/security/ipe/ipe-hooks.h index 5e46726f2562..b2417831cfc1 100644 --- a/security/ipe/ipe-hooks.h +++ b/security/ipe/ipe-hooks.h @@ -60,4 +60,11 @@ int ipe_on_kernel_load_data(enum kernel_load_data_id id); void ipe_sb_free_security(struct super_block *mnt_sb); +int ipe_bdev_alloc_security(struct block_device *bdev); + +void ipe_bdev_free_security(struct block_device *bdev); + +int ipe_bdev_setsecurity(struct block_device *bdev, const char *key, + const void *value, size_t len); + #endif /* IPE_HOOK_H */ diff --git a/security/ipe/ipe.c b/security/ipe/ipe.c index 706ff38083c6..8a612eb62879 100644 --- a/security/ipe/ipe.c +++ b/security/ipe/ipe.c @@ -23,6 +23,9 @@ static struct security_hook_list ipe_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(kernel_load_data, ipe_on_kernel_load_data), LSM_HOOK_INIT(file_mprotect, ipe_on_mprotect), LSM_HOOK_INIT(sb_free_security, ipe_sb_free_security), + LSM_HOOK_INIT(bdev_alloc_security, ipe_bdev_alloc_security), + LSM_HOOK_INIT(bdev_free_security, ipe_bdev_free_security), + LSM_HOOK_INIT(bdev_setsecurity, ipe_bdev_setsecurity), }; /** @@ -40,6 +43,10 @@ static int __init ipe_load_properties(void) if (rc != 0) return rc; + rc = ipe_init_dm_verity_signature(); + if (rc != 0) + return rc; + return rc; } @@ -72,9 +79,20 @@ static int __init ipe_init(void) return rc; } +struct lsm_blob_sizes ipe_blobs = { + .lbs_cred = 0, + .lbs_file = 0, + .lbs_inode = 0, + .lbs_ipc = 0, + .lbs_msg_msg = 0, + .lbs_task = 0, + .lbs_bdev = sizeof(struct ipe_bdev_blob), +}; + DEFINE_LSM(ipe) = { .name = "ipe", .init = ipe_init, + .blobs = &ipe_blobs, }; bool ipe_enforce = true; diff --git a/security/ipe/ipe.h b/security/ipe/ipe.h index af72bb574f73..a59cae2deec6 100644 --- a/security/ipe/ipe.h +++ b/security/ipe/ipe.h @@ -10,11 +10,13 @@ #include #include +#include #define IPE_MODE_ENFORCE "enforce" #define IPE_MODE_PERMISSIVE "permissive" extern bool ipe_enforce; extern bool ipe_success_audit; +extern struct lsm_blob_sizes ipe_blobs; #endif /* IPE_H */ diff --git a/security/ipe/properties/Kconfig b/security/ipe/properties/Kconfig index 75c6c6ff6cd8..4046f7e5eaef 100644 --- a/security/ipe/properties/Kconfig +++ b/security/ipe/properties/Kconfig @@ -13,3 +13,13 @@ config IPE_BOOT_PROP superblock. if unsure, answer N. + +config IPE_DM_VERITY_SIGNATURE + bool "Enable property for signature verified dm-verity volumes" + depends on DM_VERITY_VERIFY_ROOTHASH_SIG + help + This option enables IPE's integration with Device-Mapper Verity's + signed root-hashes. This enables the usage of the property, + "dmverity_signature" in IPE's policy. + + if unsure, answer Y. diff --git a/security/ipe/properties/Makefile b/security/ipe/properties/Makefile index e3e7fe17cf58..6b67cbe36e31 100644 --- a/security/ipe/properties/Makefile +++ b/security/ipe/properties/Makefile @@ -9,3 +9,4 @@ obj-$(CONFIG_SECURITY_IPE) += properties.o properties-$(CONFIG_IPE_BOOT_PROP) += boot-verified.o +properties-$(CONFIG_IPE_DM_VERITY_SIGNATURE) += dmverity-signature.o diff --git a/security/ipe/properties/dmverity-signature.c b/security/ipe/properties/dmverity-signature.c new file mode 100644 index 000000000000..819222f226b7 --- /dev/null +++ b/security/ipe/properties/dmverity-signature.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) Microsoft Corporation. All rights reserved. + */ + +#include "../ipe.h" +#include "../ipe-pin.h" +#include "../ipe-property.h" +#include "../utility.h" + +#include +#include +#include +#include +#include + +#define PROPERTY_NAME "dmverity_signature" + +static void audit(struct audit_buffer *ab, bool value) +{ + audit_log_format(ab, "%s", (value) ? "TRUE" : "FALSE"); +} + +static inline void audit_rule_value(struct audit_buffer *ab, + const void *value) +{ + audit(ab, (bool)value); +} + +static inline void audit_ctx(struct audit_buffer *ab, + const struct ipe_engine_ctx *ctx) +{ + bool b = has_bdev(ctx->file) && ctx->sec_bdev->dmverity_rh_sig; + + audit(ab, b); +} + +static bool evaluate(const struct ipe_engine_ctx *ctx, + const void *value) +{ + bool expect = (bool)value; + + if (!has_bdev(ctx->file)) + return false; + + return ((bool)ctx->sec_bdev->dmverity_rh_sig) == expect; +} + +static int parse(const char *val_str, void **value) +{ + if (strcmp("TRUE", val_str) == 0) + *value = (void *)true; + else if (strcmp("FALSE", val_str) == 0) + *value = (void *)false; + else + return -EBADMSG; + + return 0; +} + +static inline int duplicate(const void *src, void **dest) +{ + *dest = (void *)(bool)src; + + return 0; +} + +static const struct ipe_property dmv_signature = { + .property_name = PROPERTY_NAME, + .version = 1, + .eval = evaluate, + .parse = parse, + .rule_audit = audit_rule_value, + .ctx_audit = audit_ctx, + .dup = duplicate, + .free_val = NULL, +}; + +int ipe_init_dm_verity_signature(void) +{ + return ipe_register_property(&dmv_signature); +} diff --git a/security/ipe/properties/prop-entry.h b/security/ipe/properties/prop-entry.h index f598dd9608b9..85366366ff0d 100644 --- a/security/ipe/properties/prop-entry.h +++ b/security/ipe/properties/prop-entry.h @@ -17,4 +17,13 @@ static inline int __init ipe_init_bootv(void) int __init ipe_init_bootv(void); #endif /* CONFIG_IPE_BOOT_PROP */ +#ifndef CONFIG_IPE_DM_VERITY_SIGNATURE +static inline int __init ipe_init_dm_verity_signature(void) +{ + return 0; +} +#else +int __init ipe_init_dm_verity_signature(void); +#endif /* CONFIG_IPE_DM_VERITY_SIGNATURE */ + #endif /* IPE_PROP_ENTRY_H */ diff --git a/security/ipe/utility.h b/security/ipe/utility.h index a13089bb0d8f..7580f17274a3 100644 --- a/security/ipe/utility.h +++ b/security/ipe/utility.h @@ -19,4 +19,14 @@ static inline bool has_sb(const struct file *file) return has_mount(file) && file->f_path.mnt->mnt_sb; } +static inline bool has_bdev(const struct file *file) +{ + return has_sb(file) && file->f_path.mnt->mnt_sb->s_bdev; +} + +static inline struct block_device *bdev(const struct file *file) +{ + return file->f_path.mnt->mnt_sb->s_bdev; +} + #endif /* IPE_UTILITY_H */ -- 2.27.0 -- Linux-audit mailing list Linux-audit@redhat.com https://www.redhat.com/mailman/listinfo/linux-audit