From: Tushar Sugandhi <tusharsu@linux.microsoft.com> To: zohar@linux.ibm.com, roberto.sassu@huaweicloud.com, roberto.sassu@huawei.com, eric.snowberg@oracle.com, stefanb@linux.ibm.com, ebiederm@xmission.com, noodles@fb.com, bauermann@kolabnow.com, linux-integrity@vger.kernel.org, kexec@lists.infradead.org Cc: code@tyhicks.com, nramas@linux.microsoft.com, paul@paul-moore.com Subject: [PATCH v5 8/8] ima: measure kexec load and exec events as critical data Date: Wed, 14 Feb 2024 07:38:27 -0800 [thread overview] Message-ID: <20240214153827.1087657-9-tusharsu@linux.microsoft.com> (raw) In-Reply-To: <20240214153827.1087657-1-tusharsu@linux.microsoft.com> The amount of memory allocated at kexec load, even with the extra memory allocated, might not be large enough for the entire measurement list. The indeterminate interval between kexec 'load' and 'execute' could exacerbate this problem. Define two new IMA events, 'kexec_load' and 'kexec_execute', to be measured as critical data at kexec 'load' and 'execute' respectively. Report the allocated kexec segment size, IMA binary log size and the runtime measurements count as part of those events. These events, and the values reported through them, serve as markers in the IMA log to verify the IMA events are captured during kexec soft reboot. The presence of a 'kexec_load' event in between the last two 'boot_aggregate' events in the IMA log implies this is a kexec soft reboot, and not a cold-boot. And the absence of 'kexec_execute' event after kexec soft reboot implies missing events in that window which results in inconsistency with TPM PCR quotes, necessitating a cold boot for a successful remote attestation. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> --- security/integrity/ima/ima_kexec.c | 34 +++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 50903d4ce880..31495a043959 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -17,6 +17,8 @@ #include "ima.h" #ifdef CONFIG_IMA_KEXEC +#define IMA_KEXEC_EVENT_LEN 256 + static struct seq_file ima_kexec_file; static void *ima_kexec_buffer; static size_t kexec_segment_size; @@ -38,6 +40,10 @@ static void ima_free_kexec_file_buf(struct seq_file *sf) static int ima_alloc_kexec_file_buf(size_t segment_size) { + char ima_kexec_event[IMA_KEXEC_EVENT_LEN]; + size_t buf_size; + long len; + /* * kexec 'load' may be called multiple times. * Free and realloc the buffer only if the segment_size is @@ -47,7 +53,7 @@ static int ima_alloc_kexec_file_buf(size_t segment_size) ima_kexec_file.size == segment_size && ima_kexec_file.read_pos == 0 && ima_kexec_file.count == sizeof(struct ima_kexec_hdr)) - return 0; + goto out; ima_free_kexec_file_buf(&ima_kexec_file); @@ -60,6 +66,18 @@ static int ima_alloc_kexec_file_buf(size_t segment_size) ima_kexec_file.read_pos = 0; ima_kexec_file.count = sizeof(struct ima_kexec_hdr); /* reserved space */ +out: + buf_size = ima_get_binary_runtime_size(); + len = atomic_long_read(&ima_htable.len); + + scnprintf(ima_kexec_event, IMA_KEXEC_EVENT_LEN, + "kexec_segment_size=%lu;ima_binary_runtime_size=%lu;" + "ima_runtime_measurements_count=%ld;", + segment_size, buf_size, len); + + ima_measure_critical_data("ima_kexec", "kexec_load", ima_kexec_event, + strlen(ima_kexec_event), false, NULL, 0); + return 0; } @@ -186,10 +204,12 @@ void ima_add_kexec_buffer(struct kimage *image) static int ima_update_kexec_buffer(struct notifier_block *self, unsigned long action, void *data) { + char ima_kexec_event[IMA_KEXEC_EVENT_LEN]; void *buf = NULL; size_t buf_size; int ret = NOTIFY_OK; bool resume = false; + long len; if (!kexec_in_progress) { pr_info("%s: No kexec in progress.\n", __func__); @@ -201,6 +221,18 @@ static int ima_update_kexec_buffer(struct notifier_block *self, return ret; } + buf_size = ima_get_binary_runtime_size(); + len = atomic_long_read(&ima_htable.len); + + scnprintf(ima_kexec_event, IMA_KEXEC_EVENT_LEN, + "kexec_segment_size=%lu;ima_binary_runtime_size=%lu;" + "ima_runtime_measurements_count=%ld;", + kexec_segment_size, buf_size, len); + + ima_measure_critical_data("ima_kexec", "kexec_execute", + ima_kexec_event, strlen(ima_kexec_event), + false, NULL, 0); + ima_measurements_suspend(); ret = ima_dump_measurement_list(&buf_size, &buf, -- 2.25.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
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From: Tushar Sugandhi <tusharsu@linux.microsoft.com> To: zohar@linux.ibm.com, roberto.sassu@huaweicloud.com, roberto.sassu@huawei.com, eric.snowberg@oracle.com, stefanb@linux.ibm.com, ebiederm@xmission.com, noodles@fb.com, bauermann@kolabnow.com, linux-integrity@vger.kernel.org, kexec@lists.infradead.org Cc: code@tyhicks.com, nramas@linux.microsoft.com, paul@paul-moore.com Subject: [PATCH v5 8/8] ima: measure kexec load and exec events as critical data Date: Wed, 14 Feb 2024 07:38:27 -0800 [thread overview] Message-ID: <20240214153827.1087657-9-tusharsu@linux.microsoft.com> (raw) In-Reply-To: <20240214153827.1087657-1-tusharsu@linux.microsoft.com> The amount of memory allocated at kexec load, even with the extra memory allocated, might not be large enough for the entire measurement list. The indeterminate interval between kexec 'load' and 'execute' could exacerbate this problem. Define two new IMA events, 'kexec_load' and 'kexec_execute', to be measured as critical data at kexec 'load' and 'execute' respectively. Report the allocated kexec segment size, IMA binary log size and the runtime measurements count as part of those events. These events, and the values reported through them, serve as markers in the IMA log to verify the IMA events are captured during kexec soft reboot. The presence of a 'kexec_load' event in between the last two 'boot_aggregate' events in the IMA log implies this is a kexec soft reboot, and not a cold-boot. And the absence of 'kexec_execute' event after kexec soft reboot implies missing events in that window which results in inconsistency with TPM PCR quotes, necessitating a cold boot for a successful remote attestation. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> --- security/integrity/ima/ima_kexec.c | 34 +++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 50903d4ce880..31495a043959 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -17,6 +17,8 @@ #include "ima.h" #ifdef CONFIG_IMA_KEXEC +#define IMA_KEXEC_EVENT_LEN 256 + static struct seq_file ima_kexec_file; static void *ima_kexec_buffer; static size_t kexec_segment_size; @@ -38,6 +40,10 @@ static void ima_free_kexec_file_buf(struct seq_file *sf) static int ima_alloc_kexec_file_buf(size_t segment_size) { + char ima_kexec_event[IMA_KEXEC_EVENT_LEN]; + size_t buf_size; + long len; + /* * kexec 'load' may be called multiple times. * Free and realloc the buffer only if the segment_size is @@ -47,7 +53,7 @@ static int ima_alloc_kexec_file_buf(size_t segment_size) ima_kexec_file.size == segment_size && ima_kexec_file.read_pos == 0 && ima_kexec_file.count == sizeof(struct ima_kexec_hdr)) - return 0; + goto out; ima_free_kexec_file_buf(&ima_kexec_file); @@ -60,6 +66,18 @@ static int ima_alloc_kexec_file_buf(size_t segment_size) ima_kexec_file.read_pos = 0; ima_kexec_file.count = sizeof(struct ima_kexec_hdr); /* reserved space */ +out: + buf_size = ima_get_binary_runtime_size(); + len = atomic_long_read(&ima_htable.len); + + scnprintf(ima_kexec_event, IMA_KEXEC_EVENT_LEN, + "kexec_segment_size=%lu;ima_binary_runtime_size=%lu;" + "ima_runtime_measurements_count=%ld;", + segment_size, buf_size, len); + + ima_measure_critical_data("ima_kexec", "kexec_load", ima_kexec_event, + strlen(ima_kexec_event), false, NULL, 0); + return 0; } @@ -186,10 +204,12 @@ void ima_add_kexec_buffer(struct kimage *image) static int ima_update_kexec_buffer(struct notifier_block *self, unsigned long action, void *data) { + char ima_kexec_event[IMA_KEXEC_EVENT_LEN]; void *buf = NULL; size_t buf_size; int ret = NOTIFY_OK; bool resume = false; + long len; if (!kexec_in_progress) { pr_info("%s: No kexec in progress.\n", __func__); @@ -201,6 +221,18 @@ static int ima_update_kexec_buffer(struct notifier_block *self, return ret; } + buf_size = ima_get_binary_runtime_size(); + len = atomic_long_read(&ima_htable.len); + + scnprintf(ima_kexec_event, IMA_KEXEC_EVENT_LEN, + "kexec_segment_size=%lu;ima_binary_runtime_size=%lu;" + "ima_runtime_measurements_count=%ld;", + kexec_segment_size, buf_size, len); + + ima_measure_critical_data("ima_kexec", "kexec_execute", + ima_kexec_event, strlen(ima_kexec_event), + false, NULL, 0); + ima_measurements_suspend(); ret = ima_dump_measurement_list(&buf_size, &buf, -- 2.25.1
next prev parent reply other threads:[~2024-02-14 15:38 UTC|newest] Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-02-14 15:38 [PATCH v5 0/8] ima: kexec: measure events between kexec load and execute Tushar Sugandhi 2024-02-14 15:38 ` Tushar Sugandhi 2024-02-14 15:38 ` [PATCH v5 1/8] ima: define and call ima_alloc_kexec_file_buf Tushar Sugandhi 2024-02-14 15:38 ` Tushar Sugandhi 2024-02-19 22:16 ` Stefan Berger 2024-02-19 22:16 ` Stefan Berger 2024-02-21 0:12 ` Mimi Zohar 2024-02-21 0:12 ` Mimi Zohar 2024-02-14 15:38 ` [PATCH v5 2/8] kexec: define functions to map and unmap segments Tushar Sugandhi 2024-02-14 15:38 ` Tushar Sugandhi 2024-02-14 19:43 ` Stefan Berger 2024-02-14 19:43 ` Stefan Berger 2024-02-15 6:13 ` Tushar Sugandhi 2024-02-15 6:13 ` Tushar Sugandhi 2024-02-21 20:22 ` Mimi Zohar 2024-02-21 20:22 ` Mimi Zohar 2024-02-14 15:38 ` [PATCH v5 3/8] ima: kexec: skip IMA segment validation after kexec soft reboot Tushar Sugandhi 2024-02-14 15:38 ` Tushar Sugandhi 2024-02-14 15:38 ` [PATCH v5 4/8] ima: kexec: define functions to copy IMA log at soft boot Tushar Sugandhi 2024-02-14 15:38 ` Tushar Sugandhi 2024-02-14 20:47 ` Stefan Berger 2024-02-14 20:47 ` Stefan Berger 2024-02-15 6:55 ` Tushar Sugandhi 2024-02-15 6:55 ` Tushar Sugandhi 2024-02-21 21:52 ` Mimi Zohar 2024-02-21 21:52 ` Mimi Zohar 2024-02-21 22:39 ` Mimi Zohar 2024-02-21 22:39 ` Mimi Zohar 2024-03-01 11:12 ` Petr Tesařík 2024-03-01 11:12 ` Petr Tesařík 2024-02-14 15:38 ` [PATCH v5 5/8] ima: kexec: move IMA log copy from kexec load to execute Tushar Sugandhi 2024-02-14 15:38 ` Tushar Sugandhi 2024-02-14 20:58 ` Stefan Berger 2024-02-14 20:58 ` Stefan Berger 2024-02-22 1:47 ` Mimi Zohar 2024-02-22 1:47 ` Mimi Zohar 2024-05-09 6:32 ` Petr Tesařík 2024-05-09 6:32 ` Petr Tesařík 2024-02-14 15:38 ` [PATCH v5 6/8] ima: suspend measurements during buffer copy at kexec execute Tushar Sugandhi 2024-02-14 15:38 ` Tushar Sugandhi 2024-02-22 14:14 ` Mimi Zohar 2024-02-22 14:14 ` Mimi Zohar 2024-02-22 16:38 ` Mimi Zohar 2024-02-22 16:38 ` Mimi Zohar 2024-02-29 13:21 ` Petr Tesařík 2024-02-29 13:21 ` Petr Tesařík 2024-02-14 15:38 ` [PATCH v5 7/8] ima: make the kexec extra memory configurable Tushar Sugandhi 2024-02-14 15:38 ` Tushar Sugandhi 2024-02-22 14:13 ` Mimi Zohar 2024-02-22 14:13 ` Mimi Zohar 2024-02-14 15:38 ` Tushar Sugandhi [this message] 2024-02-14 15:38 ` [PATCH v5 8/8] ima: measure kexec load and exec events as critical data Tushar Sugandhi 2024-02-14 21:00 ` Stefan Berger 2024-02-14 21:00 ` Stefan Berger 2024-02-15 6:57 ` Tushar Sugandhi 2024-02-15 6:57 ` Tushar Sugandhi 2024-02-14 21:03 ` Stefan Berger 2024-02-14 21:03 ` Stefan Berger 2024-02-15 6:58 ` Tushar Sugandhi 2024-02-15 6:58 ` Tushar Sugandhi 2024-02-21 0:15 ` [PATCH v5 0/8] ima: kexec: measure events between kexec load and execute Mimi Zohar 2024-02-21 0:15 ` Mimi Zohar
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