[RFC][PATCH v4 1/9] ima: Introduce hook DIGEST_LIST_CHECK
From: Roberto Sassu <hidden>
Date: 2024-11-19 11:01:53
Also in:
linux-doc, linux-integrity, lkml
Subsystem:
extended verification module (evm), integrity measurement architecture (ima), security subsystem, the rest · Maintainers:
Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
From: Roberto Sassu <roberto.sassu@huawei.com> Introduce DIGEST_LIST_CHECK, a new hook to check the integrity of digest lists. The new hook is invoked during a kernel read with the file type READING_DIGEST LIST, which is done by the Integrity Digest Cache when it is populating a digest cache with a digest list. The new hook makes it possible to more precisely measure/appraise the digest lists read by the kernel, as opposed to using the more generic FILE_CHECK hook, invoked for every file open. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> --- Documentation/ABI/testing/ima_policy | 1 + security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_main.c | 3 ++- security/integrity/ima/ima_policy.c | 3 +++ 4 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index c2385183826c..22237fec5532 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy@@ -36,6 +36,7 @@ Description: [KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK] [KEXEC_CMDLINE] [KEY_CHECK] [CRITICAL_DATA] [SETXATTR_CHECK][MMAP_CHECK_REQPROT] + [DIGEST_LIST_CHECK] mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND] [[^]MAY_EXEC] fsmagic:= hex value
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 2eaa7f224da4..301f4ddfa487 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h@@ -317,6 +317,7 @@ static inline unsigned int ima_hash_key(u8 *digest) hook(KEY_CHECK, key) \ hook(CRITICAL_DATA, critical_data) \ hook(SETXATTR_CHECK, setxattr_check) \ + hook(DIGEST_LIST_CHECK, digest_list_check) \ hook(MAX_CHECK, none) #define __ima_hook_enumify(ENUM, str) ENUM,
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index f6cc0c7a6244..8f732d3bd024 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c@@ -798,7 +798,8 @@ const int read_idmap[READING_MAX_ID] = { [READING_MODULE] = MODULE_CHECK, [READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK, [READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK, - [READING_POLICY] = POLICY_CHECK + [READING_POLICY] = POLICY_CHECK, + [READING_DIGEST_LIST] = DIGEST_LIST_CHECK, }; /**
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 09da8e639239..047d50c2eb57 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c@@ -1290,6 +1290,7 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) case MODULE_CHECK: case KEXEC_KERNEL_CHECK: case KEXEC_INITRAMFS_CHECK: + case DIGEST_LIST_CHECK: if (entry->flags & ~(IMA_FUNC | IMA_MASK | IMA_FSMAGIC | IMA_UID | IMA_FOWNER | IMA_FSUUID | IMA_INMASK | IMA_EUID | IMA_PCR |
@@ -1533,6 +1534,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) entry->func = CRITICAL_DATA; else if (strcmp(args[0].from, "SETXATTR_CHECK") == 0) entry->func = SETXATTR_CHECK; + else if (strcmp(args[0].from, "DIGEST_LIST_CHECK") == 0) + entry->func = DIGEST_LIST_CHECK; else result = -EINVAL; if (!result)
--
2.47.0.118.gfd3785337b