kernel/linux.git/security/integrity/integrity.h, branch v5.18.16

Merge tag 'integrity-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

2022-03-22T03:44:37+00:00

Pull integrity subsystem updates from Mimi Zohar: "Except for extending the 'encrypted' key type to support user provided data, the rest is code cleanup, __setup() usage bug fix, and a trivial change" * tag 'integrity-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: MAINTAINERS: add missing security/integrity/platform_certs EVM: fix the evm= __setup handler return value KEYS: encrypted: Instantiate key with user-provided decrypted data ima: define ima_max_digest_data struct without a flexible array variable ima: rename IMA_ACTION_FLAGS to IMA_NONACTION_FLAGS ima: Return error code obtained from securityfs functions MAINTAINERS: add missing "security/integrity" directory ima: Fix trivial typos in the comments

integrity: Only use machine keyring when uefi_check_trust_mok_keys is true

2022-03-08T11:55:52+00:00

With the introduction of uefi_check_trust_mok_keys, it signifies the end- user wants to trust the machine keyring as trusted keys. If they have chosen to trust the machine keyring, load the qualifying keys into it during boot, then link it to the secondary keyring . If the user has not chosen to trust the machine keyring, it will be empty and not linked to the secondary keyring. Signed-off-by: Eric Snowberg Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen

integrity: Introduce a Linux keyring called machine

2022-03-08T11:55:52+00:00

Many UEFI Linux distributions boot using shim. The UEFI shim provides what is called Machine Owner Keys (MOK). Shim uses both the UEFI Secure Boot DB and MOK keys to validate the next step in the boot chain. The MOK facility can be used to import user generated keys. These keys can be used to sign an end-users development kernel build. When Linux boots, both UEFI Secure Boot DB and MOK keys get loaded in the Linux .platform keyring. Define a new Linux keyring called machine. This keyring shall contain just MOK keys and not the remaining keys in the platform keyring. This new machine keyring will be used in follow on patches. Unlike keys in the platform keyring, keys contained in the machine keyring will be trusted within the kernel if the end-user has chosen to do so. Signed-off-by: Eric Snowberg Tested-by: Jarkko Sakkinen Tested-by: Mimi Zohar Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen

ima: define ima_max_digest_data struct without a flexible array variable

2022-02-15T16:52:06+00:00

To support larger hash digests in the 'iint' cache, instead of defining the 'digest' field as the maximum digest size, the 'digest' field was defined as a flexible array variable. The "ima_digest_data" struct was wrapped inside a local structure with the maximum digest size. But before adding the record to the iint cache, memory for the exact digest size was dynamically allocated. The original reason for defining the 'digest' field as a flexible array variable is still valid for the 'iint' cache use case. Instead of wrapping the 'ima_digest_data' struct in a local structure define 'ima_max_digest_data' struct. Reviewed-by: Stefan Berger Signed-off-by: Mimi Zohar

ima: rename IMA_ACTION_FLAGS to IMA_NONACTION_FLAGS

2022-02-15T16:21:59+00:00

Simple policy rule options, such as fowner, uid, or euid, can be checked immediately, while other policy rule options, such as requiring a file signature, need to be deferred. The 'flags' field in the integrity_iint_cache struct contains the policy action', 'subaction', and non action/subaction. action: measure/measured, appraise/appraised, (collect)/collected, audit/audited subaction: appraise status for each hook (e.g. file, mmap, bprm, read, creds) non action/subaction: deferred policy rule options and state Rename the IMA_ACTION_FLAGS to IMA_NONACTION_FLAGS. Reviewed-by: Stefan Berger Signed-off-by: Mimi Zohar

crypto: sha - split sha.h into sha1.h and sha2.h

2020-11-20T03:45:33+00:00

Currently contains declarations for both SHA-1 and SHA-2, and contains declarations for SHA-3. This organization is inconsistent, but more importantly SHA-1 is no longer considered to be cryptographically secure. So to the extent possible, SHA-1 shouldn't be grouped together with any of the other SHA versions, and usage of it should be phased out. Therefore, split into two headers and , and make everyone explicitly specify whether they want the declarations for SHA-1, SHA-2, or both. This avoids making the SHA-1 declarations visible to files that don't want anything to do with SHA-1. It also prepares for potentially moving sha1.h into a new insecure/ or dangerous/ directory. Signed-off-by: Eric Biggers Acked-by: Ard Biesheuvel Acked-by: Jason A. Donenfeld Signed-off-by: Herbert Xu

integrity: Add errno field in audit message

2020-07-17T01:48:11+00:00

Error code is not included in the audit messages logged by the integrity subsystem. Define a new function integrity_audit_message() that takes error code in the "errno" parameter. Add "errno" field in the audit messages logged by the integrity subsystem and set the value passed in the "errno" parameter. [ 6.303048] audit: type=1804 audit(1592506281.627:2): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=kernel op=measuring_key cause=ENOMEM comm="swapper/0" name=".builtin_trusted_keys" res=0 errno=-12 [ 7.987647] audit: type=1802 audit(1592506283.312:9): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 op=policy_update cause=completed comm="systemd" res=1 errno=0 [ 8.019432] audit: type=1804 audit(1592506283.344:10): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 op=measuring_kexec_cmdline cause=hashing_error comm="systemd" name="kexec-cmdline" res=0 errno=-22 Signed-off-by: Lakshmi Ramasubramanian Suggested-by: Steve Grubb Suggested-by: Mimi Zohar Signed-off-by: Mimi Zohar

ima: Replace zero-length array with flexible-array

2020-06-16T04:08:32+00:00

There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://github.com/KSPP/linux/issues/21 Signed-off-by: Gustavo A. R. Silva

integrity: Remove duplicate pr_fmt definitions

2020-02-28T19:32:58+00:00

The #define for formatting log messages, pr_fmt, is duplicated in the files under security/integrity. This change moves the definition to security/integrity/integrity.h and removes the duplicate definitions in the other files under security/integrity. With this change, the messages in the following files will be prefixed with 'integrity'. security/integrity/platform_certs/platform_keyring.c security/integrity/platform_certs/load_powerpc.c security/integrity/platform_certs/load_uefi.c security/integrity/iint.c e.g. "integrity: Error adding keys to platform keyring %s\n" And the messages in the following file will be prefixed with 'ima'. security/integrity/ima/ima_mok.c e.g. "ima: Allocating IMA blacklist keyring.\n" For the rest of the files under security/integrity, there will be no change in the message format. Suggested-by: Shuah Khan Suggested-by: Joe Perches Signed-off-by: Tushar Sugandhi Reviewed-by: Lakshmi Ramasubramanian Signed-off-by: Mimi Zohar

ima: Check against blacklisted hashes for files with modsig

2019-11-12T01:25:50+00:00

Asymmetric private keys are used to sign multiple files. The kernel currently supports checking against blacklisted keys. However, if the public key is blacklisted, any file signed by the blacklisted key will automatically fail signature verification. Blacklisting the public key is not fine enough granularity, as we might want to only blacklist a particular file. This patch adds support for checking against the blacklisted hash of the file, without the appended signature, based on the IMA policy. It defines a new policy option "appraise_flag=check_blacklist". In addition to the blacklisted binary hashes stored in the firmware "dbx" variable, the Linux kernel may be configured to load blacklisted binary hashes onto the .blacklist keyring as well. The following example shows how to blacklist a specific kernel module hash. $ sha256sum kernel/kheaders.ko 77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 kernel/kheaders.ko $ grep BLACKLIST .config CONFIG_SYSTEM_BLACKLIST_KEYRING=y CONFIG_SYSTEM_BLACKLIST_HASH_LIST="blacklist-hash-list" $ cat certs/blacklist-hash-list "bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3" Update the IMA custom measurement and appraisal policy rules (/etc/ima-policy): measure func=MODULE_CHECK template=ima-modsig appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig After building, installing, and rebooting the kernel: 545660333 ---lswrv 0 0 \_ blacklist: bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 measure func=MODULE_CHECK template=ima-modsig appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig modprobe: ERROR: could not insert 'kheaders': Permission denied 10 0c9834db5a0182c1fb0cdc5d3adcf11a11fd83dd ima-sig sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40 2 /usr/lib/modules/5.4.0-rc3+/kernel/kernel/kheaders.ko 10 82aad2bcc3fa8ed94762356b5c14838f3bcfa6a0 ima-modsig sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40 2 /usr/lib/modules/5.4.0rc3+/kernel/kernel/kheaders.ko sha256:77fa889b3 5a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 3082029a06092a864886f70d010702a082028b30820287020101310d300b0609608648 016503040201300b06092a864886f70d01070131820264.... 10 25b72217cc1152b44b134ce2cd68f12dfb71acb3 ima-buf sha256:8b58427fedcf8f4b20bc8dc007f2e232bf7285d7b93a66476321f9c2a3aa132 b blacklisted-hash 77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3 Signed-off-by: Nayna Jain [zohar@linux.ibm.com: updated patch description] Signed-off-by: Mimi Zohar Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1572492694-6520-8-git-send-email-zohar@linux.ibm.com