linux-dev/security/integrity, branch linus/master

Merge tag 'integrity-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

2022-05-24T20:50:39Z

Pull IMA updates from Mimi Zohar: "New is IMA support for including fs-verity file digests and signatures in the IMA measurement list as well as verifying the fs-verity file digest based signatures, both based on policy. In addition, are two bug fixes: - avoid reading UEFI variables, which cause a page fault, on Apple Macs with T2 chips. - remove the original "ima" template Kconfig option to address a boot command line ordering issue. The rest is a mixture of code/documentation cleanup" * tag 'integrity-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: integrity: Fix sparse warnings in keyring_handler evm: Clean up some variables evm: Return INTEGRITY_PASS for enum integrity_status value '0' efi: Do not import certificates from UEFI Secure Boot for T2 Macs fsverity: update the documentation ima: support fs-verity file digest based version 3 signatures ima: permit fsverity's file digests in the IMA measurement list ima: define a new template field named 'd-ngv2' and templates fs-verity: define a function to return the integrity protected file digest ima: use IMA default hash algorithm for integrity violations ima: fix 'd-ng' comments and documentation ima: remove the IMA_TEMPLATE Kconfig option ima: remove redundant initialization of pointer 'file'.

certs: Factor out the blacklist hash creation

2022-05-23T15:47:49Z

Factor out the blacklist hash creation with the get_raw_hash() helper. This also centralize the "tbs" and "bin" prefixes and make them private, which help to manage them consistently. Cc: David Howells Cc: David S. Miller Cc: David Woodhouse Cc: Eric Snowberg Cc: Herbert Xu Cc: Jarkko Sakkinen Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20210712170313.884724-5-mic@digikod.net Signed-off-by: Jarkko Sakkinen

integrity: Fix sparse warnings in keyring_handler

2022-05-16T21:06:16Z

Fix the following sparse warnings: CHECK security/integrity/platform_certs/keyring_handler.c security/integrity/platform_certs/keyring_handler.c:76:16: warning: Using plain integer as NULL pointer security/integrity/platform_certs/keyring_handler.c:91:16: warning: Using plain integer as NULL pointer security/integrity/platform_certs/keyring_handler.c:106:16: warning: Using plain integer as NULL pointer Signed-off-by: Stefan Berger Signed-off-by: Mimi Zohar

evm: Clean up some variables

2022-05-16T12:14:38Z

Make hmac_tfm static since it's not used anywhere else besides the file it is in. Remove declaration of hash_tfm since it doesn't exist. Signed-off-by: Stefan Berger Signed-off-by: Mimi Zohar

evm: Return INTEGRITY_PASS for enum integrity_status value '0'

2022-05-16T12:14:38Z

Return INTEGRITY_PASS for the enum integrity_status rather than 0. Signed-off-by: Stefan Berger Signed-off-by: Mimi Zohar

efi: Do not import certificates from UEFI Secure Boot for T2 Macs

2022-05-15T12:22:04Z

On Apple T2 Macs, when Linux attempts to read the db and dbx efi variables at early boot to load UEFI Secure Boot certificates, a page fault occurs in Apple firmware code and EFI runtime services are disabled with the following logs: [Firmware Bug]: Page fault caused by firmware at PA: 0xffffb1edc0068000 WARNING: CPU: 3 PID: 104 at arch/x86/platform/efi/quirks.c:735 efi_crash_gracefully_on_page_fault+0x50/0xf0 (Removed some logs from here) Call Trace: page_fault_oops+0x4f/0x2c0 ? search_bpf_extables+0x6b/0x80 ? search_module_extables+0x50/0x80 ? search_exception_tables+0x5b/0x60 kernelmode_fixup_or_oops+0x9e/0x110 __bad_area_nosemaphore+0x155/0x190 bad_area_nosemaphore+0x16/0x20 do_kern_addr_fault+0x8c/0xa0 exc_page_fault+0xd8/0x180 asm_exc_page_fault+0x1e/0x30 (Removed some logs from here) ? __efi_call+0x28/0x30 ? switch_mm+0x20/0x30 ? efi_call_rts+0x19a/0x8e0 ? process_one_work+0x222/0x3f0 ? worker_thread+0x4a/0x3d0 ? kthread+0x17a/0x1a0 ? process_one_work+0x3f0/0x3f0 ? set_kthread_struct+0x40/0x40 ? ret_from_fork+0x22/0x30 ---[ end trace 1f82023595a5927f ]--- efi: Froze efi_rts_wq and disabled EFI Runtime Services integrity: Couldn't get size: 0x8000000000000015 integrity: MODSIGN: Couldn't get UEFI db list efi: EFI Runtime Services are disabled! integrity: Couldn't get size: 0x8000000000000015 integrity: Couldn't get UEFI dbx list integrity: Couldn't get size: 0x8000000000000015 integrity: Couldn't get mokx list integrity: Couldn't get size: 0x80000000 So we avoid reading these UEFI variables and thus prevent the crash. Cc: stable@vger.kernel.org Signed-off-by: Aditya Garg Reviewed-by: Mimi Zohar Signed-off-by: Mimi Zohar

ima: support fs-verity file digest based version 3 signatures

2022-05-05T21:41:51Z

IMA may verify a file's integrity against a "good" value stored in the 'security.ima' xattr or as an appended signature, based on policy. When the "good value" is stored in the xattr, the xattr may contain a file hash or signature. In either case, the "good" value is preceded by a header. The first byte of the xattr header indicates the type of data - hash, signature - stored in the xattr. To support storing fs-verity signatures in the 'security.ima' xattr requires further differentiating the fs-verity signature from the existing IMA signature. In addition the signatures stored in 'security.ima' xattr, need to be disambiguated. Instead of directly signing the fs-verity digest, a new signature format version 3 is defined as the hash of the ima_file_id structure, which identifies the type of signature and the digest. The IMA policy defines "which" files are to be measured, verified, and/or audited. For those files being verified, the policy rules indicate "how" the file should be verified. For example to require a file be signed, the appraise policy rule must include the 'appraise_type' option. appraise_type:= [imasig] | [imasig|modsig] | [sigv3] where 'imasig' is the original or signature format v2 (default), where 'modsig' is an appended signature, where 'sigv3' is the signature format v3. The policy rule must also indicate the type of digest, if not the IMA default, by first specifying the digest type: digest_type:= [verity] The following policy rule requires fsverity signatures. The rule may be constrained, for example based on a fsuuid or LSM label. appraise func=BPRM_CHECK digest_type=verity appraise_type=sigv3 Acked-by: Stefan Berger Signed-off-by: Mimi Zohar

ima: permit fsverity's file digests in the IMA measurement list

2022-05-05T15:49:13Z

Permit fsverity's file digest (a hash of struct fsverity_descriptor) to be included in the IMA measurement list, based on the new measurement policy rule 'digest_type=verity' option. To differentiate between a regular IMA file hash from an fsverity's file digest, use the new d-ngv2 format field included in the ima-ngv2 template. The following policy rule requires fsverity file digests and specifies the new 'ima-ngv2' template, which contains the new 'd-ngv2' field. The policy rule may be constrained, for example based on a fsuuid or LSM label. measure func=FILE_CHECK digest_type=verity template=ima-ngv2 Acked-by: Stefan Berger Signed-off-by: Mimi Zohar

ima: define a new template field named 'd-ngv2' and templates

2022-05-05T15:49:13Z

In preparation to differentiate between unsigned regular IMA file hashes and fs-verity's file digests in the IMA measurement list, define a new template field named 'd-ngv2'. Also define two new templates named 'ima-ngv2' and 'ima-sigv2', which include the new 'd-ngv2' field. Signed-off-by: Mimi Zohar

ima: use IMA default hash algorithm for integrity violations

2022-05-01T20:39:10Z

Integrity file violations - ToM/ToU, open writers - are recorded in the IMA measurement list, containing 0x00's in both the template data and file data hash fields, but 0xFF's are actually extended into TPM PCRs. Although the original 'ima' template data field ('d') is limited to 20 bytes, the 'd-ng' template digest field is not. The violation file data hash template field ('d-ng') is unnecessarily hard coded to SHA1. Instead of simply replacing the hard coded SHA1 hash algorithm with a larger hash algorithm, use the hash algorithm as defined in "ima_hash_algo". ima_hash_algo is set to either the Kconfig IMA default hash algorithm or as defined on the boot command line (ima_hash=). Including a non-SHA1 file data hash algorithm in the 'd-ng' field of violations is a cosmetic change. The template data hash field, which is extended into the TPM PCRs, is not affected by this change and should not affect attestation of the IMA measurement list. Tested-by: Stefan Berger Signed-off-by: Mimi Zohar