kernel/linux.git/security/integrity/evm/evm_main.c, branch linux-5.3.y

Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

2019-07-09T03:28:59+00:00

Pull integrity updates from Mimi Zohar: "Bug fixes, code clean up, and new features: - IMA policy rules can be defined in terms of LSM labels, making the IMA policy dependent on LSM policy label changes, in particular LSM label deletions. The new environment, in which IMA-appraisal is being used, frequently updates the LSM policy and permits LSM label deletions. - Prevent an mmap'ed shared file opened for write from also being mmap'ed execute. In the long term, making this and other similar changes at the VFS layer would be preferable. - The IMA per policy rule template format support is needed for a couple of new/proposed features (eg. kexec boot command line measurement, appended signatures, and VFS provided file hashes). - Other than the "boot-aggregate" record in the IMA measuremeent list, all other measurements are of file data. Measuring and storing the kexec boot command line in the IMA measurement list is the first buffer based measurement included in the measurement list" * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: integrity: Introduce struct evm_xattr ima: Update MAX_TEMPLATE_NAME_LEN to fit largest reasonable definition KEXEC: Call ima_kexec_cmdline to measure the boot command line args IMA: Define a new template field buf IMA: Define a new hook to measure the kexec boot command line arguments IMA: support for per policy rule template formats integrity: Fix __integrity_init_keyring() section mismatch ima: Use designated initializers for struct ima_event_data ima: use the lsm policy update notifier LSM: switch to blocking policy update notifiers x86/ima: fix the Kconfig dependency for IMA_ARCH_POLICY ima: Make arch_policy_entry static ima: prevent a file already mmap'ed write to be mmap'ed execute x86/ima: check EFI SetupMode too

integrity: Introduce struct evm_xattr

2019-06-30T21:54:41+00:00

Even though struct evm_ima_xattr_data includes a fixed-size array to hold a SHA1 digest, most of the code ignores the array and uses the struct to mean "type indicator followed by data of unspecified size" and tracks the real size of what the struct represents in a separate length variable. The only exception to that is the EVM code, which correctly uses the definition of struct evm_ima_xattr_data. So make this explicit in the code by removing the length specification from the array in struct evm_ima_xattr_data. Also, change the name of the element from digest to data since in most places the array doesn't hold a digest. A separate struct evm_xattr is introduced, with the original definition of evm_ima_xattr_data to be used in the places that actually expect that definition, specifically the EVM HMAC code. Signed-off-by: Thiago Jung Bauermann Signed-off-by: Mimi Zohar

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441

2019-06-05T15:37:17+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Armijn Hemel Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de Signed-off-by: Greg Kroah-Hartman

evm: remove set but not used variable 'xattr'

2019-02-04T22:36:01+00:00

Fixes gcc '-Wunused-but-set-variable' warning: security/integrity/evm/evm_main.c: In function 'init_evm': security/integrity/evm/evm_main.c:566:21: warning: variable 'xattr' set but not used [-Wunused-but-set-variable] Commit 21af76631476 ("EVM: turn evm_config_xattrnames into a list") defined and set "xattr", but never used it. [zohar@linux.ibm.com: tweaked the patch description explanation] Signed-off-by: YueHaibing Signed-off-by: Mimi Zohar

security: integrity: make evm_main explicitly non-modular

2018-12-12T22:58:50+00:00

The Makefile/Kconfig entry controlling compilation of this code is: obj-$(CONFIG_EVM) += evm.o evm-y := evm_main.o evm_crypto.o evm_secfs.o security/integrity/evm/Kconfig:config EVM security/integrity/evm/Kconfig: bool "EVM support" ...meaning that it currently is not being built as a module by anyone. Lets remove the couple traces of modular infrastructure use, so that when reading the driver there is no doubt it is builtin-only. We also delete the MODULE_LICENSE tag etc. since all that information is already contained at the top of the file in the comments. Cc: Mimi Zohar Cc: James Morris Cc: "Serge E. Hallyn" Cc: linux-ima-devel@lists.sourceforge.net Cc: linux-security-module@vger.kernel.org Signed-off-by: Paul Gortmaker Signed-off-by: James Morris

evm: Allow non-SHA1 digital signatures

2018-07-18T11:27:22+00:00

SHA1 is reasonable in HMAC constructs, but it's desirable to be able to use stronger hashes in digital signatures. Modify the EVM crypto code so the hash type is imported from the digital signature and passed down to the hash calculation code, and return the digest size to higher layers for validation. Signed-off-by: Matthew Garrett Signed-off-by: Mimi Zohar

EVM: Allow runtime modification of the set of verified xattrs

2018-05-18T19:34:45+00:00

Sites may wish to provide additional metadata alongside files in order to make more fine-grained security decisions[1]. The security of this is enhanced if this metadata is protected, something that EVM makes possible. However, the kernel cannot know about the set of extended attributes that local admins may wish to protect, and hardcoding this policy in the kernel makes it difficult to change over time and less convenient for distributions to enable. This patch adds a new /sys/kernel/security/integrity/evm/evm_xattrs node, which can be read to obtain the current set of EVM-protected extended attributes or written to in order to add new entries. Extending this list will not change the validity of any existing signatures provided that the file in question does not have any of the additional extended attributes - missing xattrs are skipped when calculating the EVM hash. [1] For instance, a package manager could install information about the package uploader in an additional extended attribute. Local LSM policy could then be associated with that extended attribute in order to restrict the privileges available to packages from less trusted uploaders. Signed-off-by: Matthew Garrett Reviewed-by: James Morris Signed-off-by: Mimi Zohar

EVM: turn evm_config_xattrnames into a list

2018-05-18T19:34:36+00:00

Use a list of xattrs rather than an array - this makes it easier to extend the list at runtime. Signed-off-by: Matthew Garrett Reviewed-by: James Morris Signed-off-by: Mimi Zohar

evm: check for remount ro in progress before writing

2018-03-25T11:26:31+00:00

EVM might update the evm xattr while the VFS performs a remount to readonly mode. This is not properly checked for, additionally check the s_readonly_remount superblock flag before writing. The bug can for example be observed with UBIFS. UBIFS checks the free space on the device before and after a remount. With EVM enabled the free space sometimes differs between both checks. Signed-off-by: Sascha Hauer Signed-off-by: Mimi Zohar

evm: Constify *integrity_status_msg[]

2018-03-23T10:31:37+00:00

There is no gain from doing this except for some self-documenting. Signed-off-by: Hernán Gonzalez Signed-off-by: Mimi Zohar