linux-dev/security/Kconfig.hardening, branch master

Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-10-11T00:53:04Z

Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...

security: kmsan: fix interoperability with auto-initialization

2022-10-03T21:03:23Z

Heap and stack initialization is great, but not when we are trying uses of uninitialized memory. When the kernel is built with KMSAN, having kernel memory initialization enabled may introduce false negatives. We disable CONFIG_INIT_STACK_ALL_PATTERN and CONFIG_INIT_STACK_ALL_ZERO under CONFIG_KMSAN, making it impossible to auto-initialize stack variables in KMSAN builds. We also disable CONFIG_INIT_ON_ALLOC_DEFAULT_ON and CONFIG_INIT_ON_FREE_DEFAULT_ON to prevent accidental use of heap auto-initialization. We however still let the users enable heap auto-initialization at boot-time (by setting init_on_alloc=1 or init_on_free=1), in which case a warning is printed. Link: https://lkml.kernel.org/r/20220915150417.722975-31-glider@google.com Signed-off-by: Alexander Potapenko Cc: Alexander Viro Cc: Alexei Starovoitov Cc: Andrey Konovalov Cc: Andrey Konovalov Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Christoph Hellwig Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Eric Biggers Cc: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Herbert Xu Cc: Ilya Leoshkevich Cc: Ingo Molnar Cc: Jens Axboe Cc: Joonsoo Kim Cc: Kees Cook Cc: Marco Elver Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael S. Tsirkin Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Petr Mladek Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vegard Nossum Cc: Vlastimil Babka Signed-off-by: Andrew Morton

hardening: Remove Clang's enable flag for -ftrivial-auto-var-init=zero

2022-09-30T06:05:00Z

Now that Clang's -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang option is no longer required, remove it from the command line. Clang 16 and later will warn when it is used, which will cause Kconfig to think it can't use -ftrivial-auto-var-init=zero at all. Check for whether it is required and only use it when so. Cc: Nathan Chancellor Cc: Masahiro Yamada Cc: Nick Desaulniers Cc: linux-kbuild@vger.kernel.org Cc: llvm@lists.linux.dev Cc: stable@vger.kernel.org Fixes: f02003c860d9 ("hardening: Avoid harmless Clang option under CONFIG_INIT_STACK_ALL_ZERO") Signed-off-by: Kees Cook

randstruct: Enable Clang support

2022-05-08T08:33:07Z

Clang 15 will support randstruct via the -frandomize-layout-seed-file=... option. Update the Kconfig and Makefile to recognize this feature. Cc: Masahiro Yamada Cc: linux-kbuild@vger.kernel.org Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220503205503.3054173-7-keescook@chromium.org

randstruct: Move seed generation into scripts/basic/

2022-05-08T08:33:07Z

To enable Clang randstruct support, move the structure layout randomization seed generation out of scripts/gcc-plugins/ into scripts/basic/ so it happens early enough that it can be used by either compiler implementation. The gcc-plugin still builds its own header file, but now does so from the common "randstruct.seed" file. Cc: linux-hardening@vger.kernel.org Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220503205503.3054173-6-keescook@chromium.org

randstruct: Reorganize Kconfigs and attribute macros

2022-05-08T08:33:06Z

In preparation for Clang supporting randstruct, reorganize the Kconfigs, move the attribute macros, and generalize the feature to be named CONFIG_RANDSTRUCT for on/off, CONFIG_RANDSTRUCT_FULL for the full randomization mode, and CONFIG_RANDSTRUCT_PERFORMANCE for the cache-line sized mode. Cc: linux-hardening@vger.kernel.org Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220503205503.3054173-4-keescook@chromium.org

gcc-plugins/stackleak: Provide verbose mode

2022-02-06T18:49:57Z

In order to compare instrumentation between builds, make the verbose mode of the plugin available during the build. This is rarely needed (behind EXPERT) and very noisy (disabled for COMPILE_TEST). Cc: Alexander Popov Signed-off-by: Kees Cook

gcc-plugins: Explicitly document purpose and deprecation schedule

2021-10-21T15:41:38Z

GCC plugins should only exist when some compiler feature needs to be proven but does not exist in either GCC nor Clang. For example, if a desired feature is already in Clang, it should be added to GCC upstream. Document this explicitly. Additionally, mark the plugins with matching upstream GCC features as removable past their respective GCC versions. Cc: Masahiro Yamada Cc: Michal Marek Cc: Nick Desaulniers Cc: Jonathan Corbet Cc: James Morris Cc: "Serge E. Hallyn" Cc: Nathan Chancellor Cc: linux-hardening@vger.kernel.org Cc: linux-kbuild@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: llvm@lists.linux.dev Signed-off-by: Kees Cook Reviewed-by: Nathan Chancellor Reviewed-by: Miguel Ojeda Acked-by: Nick Desaulniers Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20211020173554.38122-2-keescook@chromium.org

hardening: Avoid harmless Clang option under CONFIG_INIT_STACK_ALL_ZERO

2021-09-25T15:22:59Z

Currently under Clang, CC_HAS_AUTO_VAR_INIT_ZERO requires an extra -enable flag compared to CC_HAS_AUTO_VAR_INIT_PATTERN. GCC 12[1] will not, and will happily ignore the Clang-specific flag. However, its presence on the command-line is both cumbersome and confusing. Due to GCC's tolerant behavior, though, we can continue to use a single Kconfig cc-option test for the feature on both compilers, but then drop the Clang-specific option in the Makefile. In other words, this patch does not change anything other than making the compiler command line shorter once GCC supports -ftrivial-auto-var-init=zero. [1] https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=a25e0b5e6ac8a77a71c229e0a7b744603365b0e9 Cc: Greg Kroah-Hartman Cc: Masahiro Yamada Cc: llvm@lists.linux.dev Fixes: dcb7c0b9461c ("hardening: Clarify Kconfig text for auto-var-init") Suggested-by: Will Deacon Link: https://lore.kernel.org/lkml/20210914102837.6172-1-will@kernel.org/ Reviewed-by: Nick Desaulniers Reviewed-by: Nathan Chancellor Acked-by: Will Deacon Signed-off-by: Kees Cook

hardening: Clarify Kconfig text for auto-var-init

2021-07-21T06:02:59Z

Clarify the details around the automatic variable initialization modes available. Specifically this details the values used for pattern init and expands on the rationale for zero init safety. Additionally makes zero init the default when available. Cc: glider@google.com Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: linux-security-module@vger.kernel.org Cc: clang-built-linux@googlegroups.com Signed-off-by: Kees Cook Acked-by: Gustavo A. R. Silva