From patchwork Fri May 20 14:26:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thore Sommer X-Patchwork-Id: 12856871 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BDC72C433F5 for ; Fri, 20 May 2022 14:26:35 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-326-LTz-bTXqP3iv4OYD0DgQHA-1; Fri, 20 May 2022 10:26:31 -0400 X-MC-Unique: LTz-bTXqP3iv4OYD0DgQHA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DFCE780B90A; Fri, 20 May 2022 14:26:29 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (unknown [10.30.29.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id 63B9D40D2821; Fri, 20 May 2022 14:26:29 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (localhost [IPv6:::1]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id 44FC2194705A; Fri, 20 May 2022 14:26:29 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id 12B95194704C for ; Fri, 20 May 2022 14:26:28 +0000 (UTC) Received: by smtp.corp.redhat.com (Postfix) id D1C3A492CA3; Fri, 20 May 2022 14:26:27 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast03.extmail.prod.ext.rdu2.redhat.com [10.11.55.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CDF09492CA2 for ; Fri, 20 May 2022 14:26:27 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-2.mimecast.com [207.211.31.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id AD1FC811E75 for ; Fri, 20 May 2022 14:26:27 +0000 (UTC) Received: from mo4-p01-ob.smtp.rzone.de (mo4-p01-ob.smtp.rzone.de [81.169.146.166]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-193-kPG50auePQ28ooJrIqPhIw-1; Fri, 20 May 2022 10:26:24 -0400 X-MC-Unique: kPG50auePQ28ooJrIqPhIw-1 X-RZG-AUTH: ":PHkGeUmrW+uCZmxs998QJRUX30nOwJd7nOD9sw/xoauycprg5uef7cgCEpy7sPc=" X-RZG-CLASS-ID: mo00 Received: from USER-PC.fritz.box by smtp.strato.de (RZmta 47.42.2 DYNA|AUTH) with ESMTPSA id Y03eaey4KEQEQD5 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Fri, 20 May 2022 16:26:14 +0200 (CEST) From: Thore Sommer To: dm-devel@redhat.com, agk@redhat.com, snitzer@redhat.com, nramas@linux.microsoft.com Date: Fri, 20 May 2022 16:26:03 +0200 Message-Id: <20220520142605.270625-2-public@thson.de> In-Reply-To: <20220520142605.270625-1-public@thson.de> References: <20220520142605.270625-1-public@thson.de> MIME-Version: 1.0 X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 Subject: [dm-devel] [PATCH 1/3] dm ima: allow targets to remeasure their table entry X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-integrity@vger.kernel.org, Thore Sommer Errors-To: dm-devel-bounces@redhat.com Sender: "dm-devel" X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com The existing device mapper IMA measurements only measure the table content on target creation. This is fine for targets that do not change their table during runtime, but some targets like verity use the table to display state changes. Those changes are not visible through the existing device mapper integration. A new DM event "dm_target_update" is introduced for targets to remeasure their table entry. This event is intended to be used by targets that change their table entries to indicate potential security relevant information. This allows for a more complete Remote Attestation of device mapper targets. For example a verity target is never marked as corrupted during creation, because it only happens when a corrupted block is read. Using the new event the table entry change will be visible in the IMA log. In the event the dm version, device metadata and target data gets measured. The hash of the active table is not updated because it would require to rehash the whole table with all the other targets entries. Signed-off-by: Thore Sommer --- - v1: - do not initialize ima_buf with NULL - use return value of scnprintf for target_metadata_buf_len - rewrite target_index calculation to use less variables - remove unnecessary NULL check for ti2 drivers/md/dm-ima.c | 70 +++++++++++++++++++++++++++++++++++++++++++++ drivers/md/dm-ima.h | 2 ++ 2 files changed, 72 insertions(+) diff --git a/drivers/md/dm-ima.c b/drivers/md/dm-ima.c index 1842d3a958ef..bac217440853 100644 --- a/drivers/md/dm-ima.c +++ b/drivers/md/dm-ima.c @@ -750,3 +750,73 @@ void dm_ima_measure_on_device_rename(struct mapped_device *md) kfree(new_dev_name); kfree(new_dev_uuid); } + +/* + * Give the option for targets to remeasure on state change. + */ +void dm_ima_measure_on_target_update(struct dm_target *ti) +{ + char *ima_buf, *target_metadata_buf = NULL, *target_data_buf = NULL; + struct dm_target *ti2; + size_t target_metadata_buf_len, target_data_buf_len; + unsigned int num_targets, target_index; + struct dm_table *table = ti->table; + struct mapped_device *md = table->md; + bool noio = true; + int l = 0; + + ima_buf = dm_ima_alloc(DM_IMA_MEASUREMENT_BUF_LEN, GFP_KERNEL, noio); + if (!ima_buf) + return; + + target_metadata_buf = dm_ima_alloc(DM_IMA_TARGET_METADATA_BUF_LEN, GFP_KERNEL, noio); + if (!target_metadata_buf) + goto exit; + + target_data_buf = dm_ima_alloc(DM_IMA_TARGET_DATA_BUF_LEN, GFP_KERNEL, noio); + if (!target_data_buf) + goto exit; + + /* + * Get the index of the target in the table. + */ + num_targets = dm_table_get_num_targets(table); + for (target_index = 0; target_index < num_targets; target_index++) { + ti2 = dm_table_get_target(table, target_index); + if (ti == ti2) + break; + } + if (target_index == num_targets) + goto exit; + + target_metadata_buf_len = scnprintf(target_metadata_buf, DM_IMA_TARGET_METADATA_BUF_LEN, + "target_index=%d,target_begin=%llu,target_len=%llu,", + target_index, ti->begin, ti->len); + + if (ti->type->status) + ti->type->status(ti, STATUSTYPE_IMA, STATUSTYPE_IMA, target_data_buf, + DM_IMA_TARGET_DATA_BUF_LEN); + else + target_data_buf[0] = '\0'; + target_data_buf_len = strlen(target_data_buf); + + memcpy(ima_buf + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len); + l += md->ima.dm_version_str_len; + + memcpy(ima_buf + l, md->ima.active_table.device_metadata, + md->ima.active_table.device_metadata_len); + l += md->ima.active_table.device_metadata_len; + + memcpy(ima_buf + l, target_metadata_buf, target_metadata_buf_len); + l += target_metadata_buf_len; + + memcpy(ima_buf + l, target_data_buf, target_data_buf_len); + + dm_ima_measure_data("dm_target_update", ima_buf, strlen(ima_buf), noio); + +exit: + kfree(ima_buf); + kfree(target_data_buf); + kfree(target_metadata_buf); +} +EXPORT_SYMBOL_GPL(dm_ima_measure_on_target_update); diff --git a/drivers/md/dm-ima.h b/drivers/md/dm-ima.h index b8c3b614670b..281a8b65f8a9 100644 --- a/drivers/md/dm-ima.h +++ b/drivers/md/dm-ima.h @@ -63,6 +63,7 @@ void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap); void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all); void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map); void dm_ima_measure_on_device_rename(struct mapped_device *md); +void dm_ima_measure_on_target_update(struct dm_target *ti); #else @@ -72,6 +73,7 @@ static inline void dm_ima_measure_on_device_resume(struct mapped_device *md, boo static inline void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all) {} static inline void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map) {} static inline void dm_ima_measure_on_device_rename(struct mapped_device *md) {} +static inline void dm_ima_measure_on_target_update(struct dm_target *ti) {} #endif /* CONFIG_IMA */ From patchwork Fri May 20 14:26:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thore Sommer X-Patchwork-Id: 12856870 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DC9C7C433EF for ; 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Fri, 20 May 2022 10:26:25 -0400 X-MC-Unique: ZxpMs9HcNU-fvalJmycC1w-1 X-RZG-AUTH: ":PHkGeUmrW+uCZmxs998QJRUX30nOwJd7nOD9sw/xoauycprg5uef7cgCEpy7sPc=" X-RZG-CLASS-ID: mo00 Received: from USER-PC.fritz.box by smtp.strato.de (RZmta 47.42.2 DYNA|AUTH) with ESMTPSA id Y03eaey4KEQHQD6 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Fri, 20 May 2022 16:26:17 +0200 (CEST) From: Thore Sommer To: dm-devel@redhat.com, agk@redhat.com, snitzer@redhat.com, nramas@linux.microsoft.com Date: Fri, 20 May 2022 16:26:04 +0200 Message-Id: <20220520142605.270625-3-public@thson.de> In-Reply-To: <20220520142605.270625-1-public@thson.de> References: <20220520142605.270625-1-public@thson.de> MIME-Version: 1.0 X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Subject: [dm-devel] [PATCH 2/3] dm verity: add support for IMA target update event X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-integrity@vger.kernel.org, Thore Sommer Errors-To: dm-devel-bounces@redhat.com Sender: "dm-devel" X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com On first corruption the verity targets triggers a "dm_target_update" event. This allows other systems to detect the corruption via IMA instead of manually querying the table. The corruption cannot be detected using the other IMA measurements because "dm_table_load" only measures the table content during target creation. Using the new "dm_target_update" remeasures the target table entries during runtime. The event is only triggered if the target was not corrupted before because verity_handle_err(..) is still called when the target is corrupted and the IMA log should only contain an entry when the table changed. Signed-off-by: Thore Sommer --- - v1: rewrite check to not use an extra variable drivers/md/dm-verity-target.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index 80133aae0db3..5133c2274057 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -16,6 +16,7 @@ #include "dm-verity.h" #include "dm-verity-fec.h" #include "dm-verity-verify-sig.h" +#include "dm-ima.h" #include #include #include @@ -219,8 +220,13 @@ static int verity_handle_err(struct dm_verity *v, enum verity_block_type type, const char *type_str = ""; struct mapped_device *md = dm_table_get_md(v->ti->table); - /* Corruption should be visible in device status in all modes */ - v->hash_failed = 1; + /* Only change and measure change if not already corrupted */ + if (!v->hash_failed) { + /* Corruption should be visible in device status in all modes */ + v->hash_failed = 1; + /* After the state has changed remeasure target table */ + dm_ima_measure_on_target_update(v->ti); + } if (v->corrupted_errs >= DM_VERITY_MAX_CORRUPTED_ERRS) goto out; From patchwork Fri May 20 14:26:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thore Sommer X-Patchwork-Id: 12856873 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6ED0FC433EF for ; Fri, 20 May 2022 14:26:37 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-600-nU-DJGDFN6ycEyTlVQbR-Q-1; Fri, 20 May 2022 10:26:34 -0400 X-MC-Unique: nU-DJGDFN6ycEyTlVQbR-Q-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CF1D41C0CE6F; 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Fri, 20 May 2022 14:26:29 +0000 (UTC) Received: from mo4-p02-ob.smtp.rzone.de (mo4-p02-ob.smtp.rzone.de [85.215.255.80]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-73-IPeBC8xtPIScHsGukEq7-Q-1; Fri, 20 May 2022 10:26:27 -0400 X-MC-Unique: IPeBC8xtPIScHsGukEq7-Q-1 X-RZG-AUTH: ":PHkGeUmrW+uCZmxs998QJRUX30nOwJd7nOD9sw/xoauycprg5uef7cgCEpy7sPc=" X-RZG-CLASS-ID: mo00 Received: from USER-PC.fritz.box by smtp.strato.de (RZmta 47.42.2 DYNA|AUTH) with ESMTPSA id Y03eaey4KEQIQD8 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Fri, 20 May 2022 16:26:18 +0200 (CEST) From: Thore Sommer To: dm-devel@redhat.com, agk@redhat.com, snitzer@redhat.com, nramas@linux.microsoft.com Date: Fri, 20 May 2022 16:26:05 +0200 Message-Id: <20220520142605.270625-4-public@thson.de> In-Reply-To: <20220520142605.270625-1-public@thson.de> References: <20220520142605.270625-1-public@thson.de> MIME-Version: 1.0 X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 Subject: [dm-devel] [PATCH 3/3] dm ima: add documentation target update event X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-integrity@vger.kernel.org, Thore Sommer Errors-To: dm-devel-bounces@redhat.com Sender: "dm-devel" X-Scanned-By: MIMEDefang 2.85 on 10.11.54.10 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com The dm_target_update event can be triggered by targets to remeasure their state to reflect that change also in IMA. This is event is currently only supported by verity. Signed-off-by: Thore Sommer --- .../admin-guide/device-mapper/dm-ima.rst | 33 +++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/Documentation/admin-guide/device-mapper/dm-ima.rst b/Documentation/admin-guide/device-mapper/dm-ima.rst index a4aa50a828e0..ac9418ea99d3 100644 --- a/Documentation/admin-guide/device-mapper/dm-ima.rst +++ b/Documentation/admin-guide/device-mapper/dm-ima.rst @@ -93,6 +93,7 @@ Following device state changes will trigger IMA measurements: #. Device remove #. Table clear #. Device rename + #. Target update 1. Table load: --------------- @@ -321,6 +322,38 @@ The IMA measurement log has the following format for 'dm_device_rename': new_name=linear\=2,new_uuid=1234-5678; current_device_capacity=1024; +6. Target update: +------------------ +When a target changes updates its table it can trigger an remeasurement of that table. + +This is currently only implemented for 'verity' targets to detect measure corruption occurrences. +Note that the active table hash of the device does not get updated. + +The IMA measurement log has the following format for 'dm_target_update': + +:: + + EVENT_NAME := "dm_target_update" + EVENT_DATA := ";" ";" ";" + + dm_version_str := As described in the 'Table load' section above. + device_active_metadata := Device metadata that reflects the currently loaded active table. + The format is same as 'device_metadata' described in the 'Table load' section above. + target_data_row + E.g: if a verity device gets corrupted then IMA ASCII measurement log will have an entry with: + (converted from ASCII to text for readability) + + 10 1cc9c660afb7fddd1b7167f0c4e997ebca8b1c09 ima-buf sha256:e991f7692724257701c8e652682bd3246837ed2d655407b9e9f5a5b469e6c75b + dm_target_update + dm_version=4.45.0; + name=test,uuid=CRYPT-VERITY-e0d2a85fd61e41238174adaa32d296fe-test,major=253,minor=0,minor_count=1,num_targets=1; + target_index=0,target_begin=0,target_len=8,target_name=verity,target_version=1.8.0,hash_failed=C, + verity_version=1,data_device_name=7:1,hash_device_name=7:0,verity_algorithm=sha256, + root_digest=8c2eff0b45fc9815b94350f7a913683ef34085c734229bcf1345c31b07ac61b8, + salt=63010b7c63e28e6929a2f020dc71c97a0660a9f377a83c674a62feb01c5ca6b3, + ignore_zero_blocks=n,check_at_most_once=n; + + Supported targets: ==================