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 3/8] ima: kexec: skip IMA segment validation after kexec soft reboot Date: Wed, 14 Feb 2024 07:38:22 -0800 [thread overview] Message-ID: <20240214153827.1087657-4-tusharsu@linux.microsoft.com> (raw) In-Reply-To: <20240214153827.1087657-1-tusharsu@linux.microsoft.com> kexec_calculate_store_digests() calculates and stores the digest of the segment at kexec_file_load syscall where the IMA segment is also allocated. With this series, the IMA segment will be updated with the measurement log at kexec soft reboot. Therefore, it may fail digest verification in verify_sha256_digest() after kexec soft reboot into the new Kernel. Therefore, the digest calculation, storage, and verification of the IMA segment needs to be skipped. Skip IMA segment from calculating and storing digest in function kexec_calculate_store_digests() so that it is not added to the 'purgatory_sha_regions'. Since verify_sha256_digest() only verifies 'purgatory_sha_regions', no change is needed in verify_sha256_digest() in this context. With this change, the IMA segment is not included in the digest calculation, storage, and verification. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> --- include/linux/kexec.h | 3 +++ kernel/kexec_file.c | 8 ++++++++ security/integrity/ima/ima_kexec.c | 3 +++ 3 files changed, 14 insertions(+) diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 3145447eb77a..73f0dd0e1787 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -358,6 +358,9 @@ struct kimage { phys_addr_t ima_buffer_addr; size_t ima_buffer_size; + + unsigned long ima_segment_index; + bool is_ima_segment_index_set; #endif /* Core ELF header buffer */ diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index bef2f6f2571b..0e3689bfb0bb 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -750,6 +750,14 @@ static int kexec_calculate_store_digests(struct kimage *image) if (ksegment->kbuf == pi->purgatory_buf) continue; + /* + * Skip the segment if ima_segment_index is set and matches + * the current index + */ + if (image->is_ima_segment_index_set && + i == image->ima_segment_index) + continue; + ret = crypto_shash_update(desc, ksegment->kbuf, ksegment->bufsz); if (ret) diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index a9cb5e882e2e..ccb072617c2d 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -161,6 +161,7 @@ void ima_add_kexec_buffer(struct kimage *image) kbuf.buffer = kexec_buffer; kbuf.bufsz = kexec_buffer_size; kbuf.memsz = kexec_segment_size; + image->is_ima_segment_index_set = false; ret = kexec_add_buffer(&kbuf); if (ret) { pr_err("Error passing over kexec measurement buffer.\n"); @@ -171,6 +172,8 @@ void ima_add_kexec_buffer(struct kimage *image) image->ima_buffer_addr = kbuf.mem; image->ima_buffer_size = kexec_segment_size; image->ima_buffer = kexec_buffer; + image->ima_segment_index = image->nr_segments - 1; + image->is_ima_segment_index_set = true; /* * kexec owns kexec_buffer after kexec_add_buffer() is called -- 2.25.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
WARNING: multiple messages have this Message-ID (diff)
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 3/8] ima: kexec: skip IMA segment validation after kexec soft reboot Date: Wed, 14 Feb 2024 07:38:22 -0800 [thread overview] Message-ID: <20240214153827.1087657-4-tusharsu@linux.microsoft.com> (raw) In-Reply-To: <20240214153827.1087657-1-tusharsu@linux.microsoft.com> kexec_calculate_store_digests() calculates and stores the digest of the segment at kexec_file_load syscall where the IMA segment is also allocated. With this series, the IMA segment will be updated with the measurement log at kexec soft reboot. Therefore, it may fail digest verification in verify_sha256_digest() after kexec soft reboot into the new Kernel. Therefore, the digest calculation, storage, and verification of the IMA segment needs to be skipped. Skip IMA segment from calculating and storing digest in function kexec_calculate_store_digests() so that it is not added to the 'purgatory_sha_regions'. Since verify_sha256_digest() only verifies 'purgatory_sha_regions', no change is needed in verify_sha256_digest() in this context. With this change, the IMA segment is not included in the digest calculation, storage, and verification. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> --- include/linux/kexec.h | 3 +++ kernel/kexec_file.c | 8 ++++++++ security/integrity/ima/ima_kexec.c | 3 +++ 3 files changed, 14 insertions(+) diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 3145447eb77a..73f0dd0e1787 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -358,6 +358,9 @@ struct kimage { phys_addr_t ima_buffer_addr; size_t ima_buffer_size; + + unsigned long ima_segment_index; + bool is_ima_segment_index_set; #endif /* Core ELF header buffer */ diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index bef2f6f2571b..0e3689bfb0bb 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -750,6 +750,14 @@ static int kexec_calculate_store_digests(struct kimage *image) if (ksegment->kbuf == pi->purgatory_buf) continue; + /* + * Skip the segment if ima_segment_index is set and matches + * the current index + */ + if (image->is_ima_segment_index_set && + i == image->ima_segment_index) + continue; + ret = crypto_shash_update(desc, ksegment->kbuf, ksegment->bufsz); if (ret) diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index a9cb5e882e2e..ccb072617c2d 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -161,6 +161,7 @@ void ima_add_kexec_buffer(struct kimage *image) kbuf.buffer = kexec_buffer; kbuf.bufsz = kexec_buffer_size; kbuf.memsz = kexec_segment_size; + image->is_ima_segment_index_set = false; ret = kexec_add_buffer(&kbuf); if (ret) { pr_err("Error passing over kexec measurement buffer.\n"); @@ -171,6 +172,8 @@ void ima_add_kexec_buffer(struct kimage *image) image->ima_buffer_addr = kbuf.mem; image->ima_buffer_size = kexec_segment_size; image->ima_buffer = kexec_buffer; + image->ima_segment_index = image->nr_segments - 1; + image->is_ima_segment_index_set = true; /* * kexec owns kexec_buffer after kexec_add_buffer() is called -- 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 ` Tushar Sugandhi [this message] 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 ` [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 ` [PATCH v5 8/8] ima: measure kexec load and exec events as critical data Tushar Sugandhi 2024-02-14 15:38 ` 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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