kernel/linux.git/security/Kconfig, branch v6.6.132

proc: add config & param to block forcing mem writes

2024-10-10T09:57:27+00:00

[ Upstream commit 41e8149c8892ed1962bd15350b3c3e6e90cba7f4 ] This adds a Kconfig option and boot param to allow removing the FOLL_FORCE flag from /proc/pid/mem write calls because it can be abused. The traditional forcing behavior is kept as default because it can break GDB and some other use cases. Previously we tried a more sophisticated approach allowing distributions to fine-tune /proc/pid/mem behavior, however that got NAK-ed by Linus [1], who prefers this simpler approach with semantics also easier to understand for users. Link: https://lore.kernel.org/lkml/CAHk-=wiGWLChxYmUA5HrT5aopZrB7_2VTa0NLZcxORgkUe5tEQ@mail.gmail.com/ [1] Cc: Doug Anderson Cc: Jeff Xu Cc: Jann Horn Cc: Kees Cook Cc: Ard Biesheuvel Cc: Christian Brauner Suggested-by: Linus Torvalds Signed-off-by: Linus Torvalds Signed-off-by: Adrian Ratiu Link: https://lore.kernel.org/r/20240802080225.89408-1-adrian.ratiu@collabora.com Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

mm/slab: remove HAVE_HARDENED_USERCOPY_ALLOCATOR

2023-05-24T13:38:17+00:00

With SLOB removed, both remaining allocators support hardened usercopy, so remove the config and associated #ifdef. Signed-off-by: Vlastimil Babka Reviewed-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Reviewed-by: Kees Cook Acked-by: David Rientjes Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>

Merge tag 'docs-6.4' of git://git.lwn.net/linux

2023-04-24T19:35:49+00:00

Pull documentation updates from Jonathan Corbet: "Commit volume in documentation is relatively low this time, but there is still a fair amount going on, including: - Reorganize the architecture-specific documentation under Documentation/arch This makes the structure match the source directory and helps to clean up the mess that is the top-level Documentation directory a bit. This work creates the new directory and moves x86 and most of the less-active architectures there. The current plan is to move the rest of the architectures in 6.5, with the patches going through the appropriate subsystem trees. - Some more Spanish translations and maintenance of the Italian translation - A new "Kernel contribution maturity model" document from Ted - A new tutorial on quickly building a trimmed kernel from Thorsten Plus the usual set of updates and fixes" * tag 'docs-6.4' of git://git.lwn.net/linux: (47 commits) media: Adjust column width for pdfdocs media: Fix building pdfdocs docs: clk: add documentation to log which clocks have been disabled docs: trace: Fix typo in ftrace.rst Documentation/process: always CC responsible lists docs: kmemleak: adjust to config renaming ELF: document some de-facto PT_* ABI quirks Documentation: arm: remove stih415/stih416 related entries docs: turn off "smart quotes" in the HTML build Documentation: firmware: Clarify firmware path usage docs/mm: Physical Memory: Fix grammar Documentation: Add document for false sharing dma-api-howto: typo fix docs: move m68k architecture documentation under Documentation/arch/ docs: move parisc documentation under Documentation/arch/ docs: move ia64 architecture docs under Documentation/arch/ docs: Move arc architecture docs under Documentation/arch/ docs: move nios2 documentation under Documentation/arch/ docs: move openrisc documentation under Documentation/arch/ docs: move superh documentation under Documentation/arch/ ...

Merge tag 'lsm-pr-20230420' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm

2023-04-24T18:21:50+00:00

Pull lsm updates from Paul Moore: - Move the LSM hook comment blocks into security/security.c For many years the LSM hook comment blocks were located in a very odd place, include/linux/lsm_hooks.h, where they lived on their own, disconnected from both the function prototypes and definitions. In keeping with current kernel conventions, this moves all of these comment blocks to the top of the function definitions, transforming them into the kdoc format in the process. This should make it much easier to maintain these comments, which are the main source of LSM hook documentation. For the most part the comment contents were left as-is, although some glaring errors were corrected. Expect additional edits in the future as we slowly update and correct the comment blocks. This is the bulk of the diffstat. - Introduce LSM_ORDER_LAST Similar to how LSM_ORDER_FIRST is used to specify LSMs which should be ordered before "normal" LSMs, the LSM_ORDER_LAST is used to specify LSMs which should be ordered after "normal" LSMs. This is one of the prerequisites for transitioning IMA/EVM to a proper LSM. - Remove the security_old_inode_init_security() hook The security_old_inode_init_security() LSM hook only allows for a single xattr which is problematic both for LSM stacking and the IMA/EVM-as-a-LSM effort. This finishes the conversion over to the security_inode_init_security() hook and removes the single-xattr LSM hook. - Fix a reiserfs problem with security xattrs During the security_old_inode_init_security() removal work it became clear that reiserfs wasn't handling security xattrs properly so we fixed it. * tag 'lsm-pr-20230420' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (32 commits) reiserfs: Add security prefix to xattr name in reiserfs_security_write() security: Remove security_old_inode_init_security() ocfs2: Switch to security_inode_init_security() reiserfs: Switch to security_inode_init_security() security: Remove integrity from the LSM list in Kconfig Revert "integrity: double check iint_cache was initialized" security: Introduce LSM_ORDER_LAST and set it for the integrity LSM device_cgroup: Fix typo in devcgroup_css_alloc description lsm: fix a badly named parameter in security_get_getsecurity() lsm: fix doc warnings in the LSM hook comments lsm: styling fixes to security/security.c lsm: move the remaining LSM hook comments to security/security.c lsm: move the io_uring hook comments to security/security.c lsm: move the perf hook comments to security/security.c lsm: move the bpf hook comments to security/security.c lsm: move the audit hook comments to security/security.c lsm: move the binder hook comments to security/security.c lsm: move the sysv hook comments to security/security.c lsm: move the key hook comments to security/security.c lsm: move the xfrm hook comments to security/security.c ...

docs: move x86 documentation into Documentation/arch/

2023-03-30T18:58:51+00:00

Move the x86 documentation under Documentation/arch/ as a way of cleaning up the top-level directory and making the structure of our docs more closely match the structure of the source directories it describes. All in-kernel references to the old paths have been updated. Acked-by: Dave Hansen Cc: linux-arch@vger.kernel.org Cc: x86@kernel.org Cc: Borislav Petkov Cc: Thomas Gleixner Link: https://lore.kernel.org/lkml/20230315211523.108836-1-corbet@lwn.net/ Signed-off-by: Jonathan Corbet

selinux: remove the runtime disable functionality

2023-03-20T16:34:23+00:00

After working with the larger SELinux-based distros for several years, we're finally at a place where we can disable the SELinux runtime disable functionality. The existing kernel deprecation notice explains the functionality and why we want to remove it: The selinuxfs "disable" node allows SELinux to be disabled at runtime prior to a policy being loaded into the kernel. If disabled via this mechanism, SELinux will remain disabled until the system is rebooted. The preferred method of disabling SELinux is via the "selinux=0" boot parameter, but the selinuxfs "disable" node was created to make it easier for systems with primitive bootloaders that did not allow for easy modification of the kernel command line. Unfortunately, allowing for SELinux to be disabled at runtime makes it difficult to secure the kernel's LSM hooks using the "__ro_after_init" feature. It is that last sentence, mentioning the '__ro_after_init' hardening, which is the real motivation for this change, and if you look at the diffstat you'll see that the impact of this patch reaches across all the different LSMs, helping prevent tampering at the LSM hook level. From a SELinux perspective, it is important to note that if you continue to disable SELinux via "/etc/selinux/config" it may appear that SELinux is disabled, but it is simply in an uninitialized state. If you load a policy with `load_policy -i`, you will see SELinux come alive just as if you had loaded the policy during early-boot. It is also worth noting that the "/sys/fs/selinux/disable" file is always writable now, regardless of the Kconfig settings, but writing to the file has no effect on the system, other than to display an error on the console if a non-zero/true value is written. Finally, in the several years where we have been working on deprecating this functionality, there has only been one instance of someone mentioning any user visible breakage. In this particular case it was an individual's kernel test system, and the workaround documented in the deprecation notice ("selinux=0" on the kernel command line) resolved the issue without problem. Acked-by: Casey Schaufler Signed-off-by: Paul Moore

security: Remove integrity from the LSM list in Kconfig

2023-03-10T23:34:33+00:00

Remove 'integrity' from the list of LSMs in Kconfig, as it is no longer necessary. Since the recent change (set order to LSM_ORDER_LAST), the 'integrity' LSM is always enabled (if selected in the kernel configuration). Signed-off-by: Roberto Sassu Acked-by: Mimi Zohar Signed-off-by: Paul Moore

x86/retbleed: Add fine grained Kconfig knobs

2022-06-29T15:43:41+00:00

Do fine-grained Kconfig for all the various retbleed parts. NOTE: if your compiler doesn't support return thunks this will silently 'upgrade' your mitigation to IBPB, you might not like this. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov

usercopy: Remove HARDENED_USERCOPY_PAGESPAN

2022-04-13T19:15:52+00:00

There isn't enough information to make this a useful check any more; the useful parts of it were moved in earlier patches, so remove this set of checks now. Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Kees Cook Reviewed-by: David Hildenbrand Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220110231530.665970-5-willy@infradead.org

Merge tag 'hardening-v5.18-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2022-03-31T18:43:01+00:00

Pull hardening updates from Kees Cook: "This addresses an -Warray-bounds warning found under a few ARM defconfigs, and disables long-broken HARDENED_USERCOPY_PAGESPAN" * tag 'hardening-v5.18-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: ARM/dma-mapping: Remove CMA code when not built with CMA usercopy: Disable CONFIG_HARDENED_USERCOPY_PAGESPAN