There are three paths through the kernel code exception logging:
- BUG (no configurable printk message)
- WARN_ON (no configurable printk message)
- WARN (configurable printk message)
LKDTM was not testing WARN_ON(). This is needed to evaluate the placement
of the "cut here" line, which needs special handling in each of the
three exceptions (and between architectures that implement instruction
exceptions to implement the code exceptions).
Signed-off-by: Kees Cook <keescook@chromium.org>
This adds a simple test for forward CFI (indirect function calls) with
function prototype granularity (as implemented by Clang's CFI).
Signed-off-by: Kees Cook <keescook@chromium.org>
Merge updates from Andrew Morton:
"Am experimenting with splitting MM up into identifiable subsystems
perhaps with a view to gitifying it in complex ways. Also with more
verbose "incoming" emails.
Most of MM is here and a few other trees.
Subsystems affected by this patch series:
- hotfixes
- iommu
- scripts
- arch/sh
- ocfs2
- mm:slab-generic
- mm:slub
- mm:kmemleak
- mm:kasan
- mm:cleanups
- mm:debug
- mm:pagecache
- mm:swap
- mm:memcg
- mm:gup
- mm:pagemap
- mm:infrastructure
- mm:vmalloc
- mm:initialization
- mm:pagealloc
- mm:vmscan
- mm:tools
- mm:proc
- mm:ras
- mm:oom-kill
hotfixes:
mm: vmscan: scan anonymous pages on file refaults
mm/nvdimm: add is_ioremap_addr and use that to check ioremap address
mm/memcontrol: fix wrong statistics in memory.stat
mm/z3fold.c: lock z3fold page before __SetPageMovable()
nilfs2: do not use unexported cpu_to_le32()/le32_to_cpu() in uapi header
MAINTAINERS: nilfs2: update email address
iommu:
include/linux/dmar.h: replace single-char identifiers in macros
scripts:
scripts/decode_stacktrace: match basepath using shell prefix operator, not regex
scripts/decode_stacktrace: look for modules with .ko.debug extension
scripts/spelling.txt: drop "sepc" from the misspelling list
scripts/spelling.txt: add spelling fix for prohibited
scripts/decode_stacktrace: Accept dash/underscore in modules
scripts/spelling.txt: add more spellings to spelling.txt
arch/sh:
arch/sh/configs/sdk7786_defconfig: remove CONFIG_LOGFS
sh: config: remove left-over BACKLIGHT_LCD_SUPPORT
sh: prevent warnings when using iounmap
ocfs2:
fs: ocfs: fix spelling mistake "hearbeating" -> "heartbeat"
ocfs2/dlm: use struct_size() helper
ocfs2: add last unlock times in locking_state
ocfs2: add locking filter debugfs file
ocfs2: add first lock wait time in locking_state
ocfs: no need to check return value of debugfs_create functions
fs/ocfs2/dlmglue.c: unneeded variable: "status"
ocfs2: use kmemdup rather than duplicating its implementation
mm:slab-generic:
Patch series "mm/slab: Improved sanity checking":
mm/slab: validate cache membership under freelist hardening
mm/slab: sanity-check page type when looking up cache
lkdtm/heap: add tests for freelist hardening
mm:slub:
mm/slub.c: avoid double string traverse in kmem_cache_flags()
slub: don't panic for memcg kmem cache creation failure
mm:kmemleak:
mm/kmemleak.c: fix check for softirq context
mm/kmemleak.c: change error at _write when kmemleak is disabled
docs: kmemleak: add more documentation details
mm:kasan:
mm/kasan: print frame description for stack bugs
Patch series "Bitops instrumentation for KASAN", v5:
lib/test_kasan: add bitops tests
x86: use static_cpu_has in uaccess region to avoid instrumentation
asm-generic, x86: add bitops instrumentation for KASAN
Patch series "mm/kasan: Add object validation in ksize()", v3:
mm/kasan: introduce __kasan_check_{read,write}
mm/kasan: change kasan_check_{read,write} to return boolean
lib/test_kasan: Add test for double-kzfree detection
mm/slab: refactor common ksize KASAN logic into slab_common.c
mm/kasan: add object validation in ksize()
mm:cleanups:
include/linux/pfn_t.h: remove pfn_t_to_virt()
Patch series "remove ARCH_SELECT_MEMORY_MODEL where it has no effect":
arm: remove ARCH_SELECT_MEMORY_MODEL
s390: remove ARCH_SELECT_MEMORY_MODEL
sparc: remove ARCH_SELECT_MEMORY_MODEL
mm/gup.c: make follow_page_mask() static
mm/memory.c: trivial clean up in insert_page()
mm: make !CONFIG_HUGE_PAGE wrappers into static inlines
include/linux/mm_types.h: ifdef struct vm_area_struct::swap_readahead_info
mm: remove the account_page_dirtied export
mm/page_isolation.c: change the prototype of undo_isolate_page_range()
include/linux/vmpressure.h: use spinlock_t instead of struct spinlock
mm: remove the exporting of totalram_pages
include/linux/pagemap.h: document trylock_page() return value
mm:debug:
mm/failslab.c: by default, do not fail allocations with direct reclaim only
Patch series "debug_pagealloc improvements":
mm, debug_pagelloc: use static keys to enable debugging
mm, page_alloc: more extensive free page checking with debug_pagealloc
mm, debug_pagealloc: use a page type instead of page_ext flag
mm:pagecache:
Patch series "fix filler_t callback type mismatches", v2:
mm/filemap.c: fix an overly long line in read_cache_page
mm/filemap: don't cast ->readpage to filler_t for do_read_cache_page
jffs2: pass the correct prototype to read_cache_page
9p: pass the correct prototype to read_cache_page
mm/filemap.c: correct the comment about VM_FAULT_RETRY
mm:swap:
mm, swap: fix race between swapoff and some swap operations
mm/swap_state.c: simplify total_swapcache_pages() with get_swap_device()
mm, swap: use rbtree for swap_extent
mm/mincore.c: fix race between swapoff and mincore
mm:memcg:
memcg, oom: no oom-kill for __GFP_RETRY_MAYFAIL
memcg, fsnotify: no oom-kill for remote memcg charging
mm, memcg: introduce memory.events.local
mm: memcontrol: dump memory.stat during cgroup OOM
Patch series "mm: reparent slab memory on cgroup removal", v7:
mm: memcg/slab: postpone kmem_cache memcg pointer initialization to memcg_link_cache()
mm: memcg/slab: rename slab delayed deactivation functions and fields
mm: memcg/slab: generalize postponed non-root kmem_cache deactivation
mm: memcg/slab: introduce __memcg_kmem_uncharge_memcg()
mm: memcg/slab: unify SLAB and SLUB page accounting
mm: memcg/slab: don't check the dying flag on kmem_cache creation
mm: memcg/slab: synchronize access to kmem_cache dying flag using a spinlock
mm: memcg/slab: rework non-root kmem_cache lifecycle management
mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages
mm: memcg/slab: reparent memcg kmem_caches on cgroup removal
mm, memcg: add a memcg_slabinfo debugfs file
mm:gup:
Patch series "switch the remaining architectures to use generic GUP", v4:
mm: use untagged_addr() for get_user_pages_fast addresses
mm: simplify gup_fast_permitted
mm: lift the x86_32 PAE version of gup_get_pte to common code
MIPS: use the generic get_user_pages_fast code
sh: add the missing pud_page definition
sh: use the generic get_user_pages_fast code
sparc64: add the missing pgd_page definition
sparc64: define untagged_addr()
sparc64: use the generic get_user_pages_fast code
mm: rename CONFIG_HAVE_GENERIC_GUP to CONFIG_HAVE_FAST_GUP
mm: reorder code blocks in gup.c
mm: consolidate the get_user_pages* implementations
mm: validate get_user_pages_fast flags
mm: move the powerpc hugepd code to mm/gup.c
mm: switch gup_hugepte to use try_get_compound_head
mm: mark the page referenced in gup_hugepte
mm/gup: speed up check_and_migrate_cma_pages() on huge page
mm/gup.c: remove some BUG_ONs from get_gate_page()
mm/gup.c: mark undo_dev_pagemap as __maybe_unused
mm:pagemap:
asm-generic, x86: introduce generic pte_{alloc,free}_one[_kernel]
alpha: switch to generic version of pte allocation
arm: switch to generic version of pte allocation
arm64: switch to generic version of pte allocation
csky: switch to generic version of pte allocation
m68k: sun3: switch to generic version of pte allocation
mips: switch to generic version of pte allocation
nds32: switch to generic version of pte allocation
nios2: switch to generic version of pte allocation
parisc: switch to generic version of pte allocation
riscv: switch to generic version of pte allocation
um: switch to generic version of pte allocation
unicore32: switch to generic version of pte allocation
mm/pgtable: drop pgtable_t variable from pte_fn_t functions
mm/memory.c: fail when offset == num in first check of __vm_map_pages()
mm:infrastructure:
mm/mmu_notifier: use hlist_add_head_rcu()
mm:vmalloc:
Patch series "Some cleanups for the KVA/vmalloc", v5:
mm/vmalloc.c: remove "node" argument
mm/vmalloc.c: preload a CPU with one object for split purpose
mm/vmalloc.c: get rid of one single unlink_va() when merge
mm/vmalloc.c: switch to WARN_ON() and move it under unlink_va()
mm/vmalloc.c: spelling> s/informaion/information/
mm:initialization:
mm/large system hash: use vmalloc for size > MAX_ORDER when !hashdist
mm/large system hash: clear hashdist when only one node with memory is booted
mm:pagealloc:
arm64: move jump_label_init() before parse_early_param()
Patch series "add init_on_alloc/init_on_free boot options", v10:
mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options
mm: init: report memory auto-initialization features at boot time
mm:vmscan:
mm: vmscan: remove double slab pressure by inc'ing sc->nr_scanned
mm: vmscan: correct some vmscan counters for THP swapout
mm:tools:
tools/vm/slabinfo: order command line options
tools/vm/slabinfo: add partial slab listing to -X
tools/vm/slabinfo: add option to sort by partial slabs
tools/vm/slabinfo: add sorting info to help menu
mm:proc:
proc: use down_read_killable mmap_sem for /proc/pid/maps
proc: use down_read_killable mmap_sem for /proc/pid/smaps_rollup
proc: use down_read_killable mmap_sem for /proc/pid/pagemap
proc: use down_read_killable mmap_sem for /proc/pid/clear_refs
proc: use down_read_killable mmap_sem for /proc/pid/map_files
mm: use down_read_killable for locking mmap_sem in access_remote_vm
mm: smaps: split PSS into components
mm: vmalloc: show number of vmalloc pages in /proc/meminfo
mm:ras:
mm/memory-failure.c: clarify error message
mm:oom-kill:
mm: memcontrol: use CSS_TASK_ITER_PROCS at mem_cgroup_scan_tasks()
mm, oom: refactor dump_tasks for memcg OOMs
mm, oom: remove redundant task_in_mem_cgroup() check
oom: decouple mems_allowed from oom_unkillable_task
mm/oom_kill.c: remove redundant OOM score normalization in select_bad_process()"
* akpm: (147 commits)
mm/oom_kill.c: remove redundant OOM score normalization in select_bad_process()
oom: decouple mems_allowed from oom_unkillable_task
mm, oom: remove redundant task_in_mem_cgroup() check
mm, oom: refactor dump_tasks for memcg OOMs
mm: memcontrol: use CSS_TASK_ITER_PROCS at mem_cgroup_scan_tasks()
mm/memory-failure.c: clarify error message
mm: vmalloc: show number of vmalloc pages in /proc/meminfo
mm: smaps: split PSS into components
mm: use down_read_killable for locking mmap_sem in access_remote_vm
proc: use down_read_killable mmap_sem for /proc/pid/map_files
proc: use down_read_killable mmap_sem for /proc/pid/clear_refs
proc: use down_read_killable mmap_sem for /proc/pid/pagemap
proc: use down_read_killable mmap_sem for /proc/pid/smaps_rollup
proc: use down_read_killable mmap_sem for /proc/pid/maps
tools/vm/slabinfo: add sorting info to help menu
tools/vm/slabinfo: add option to sort by partial slabs
tools/vm/slabinfo: add partial slab listing to -X
tools/vm/slabinfo: order command line options
mm: vmscan: correct some vmscan counters for THP swapout
mm: vmscan: remove double slab pressure by inc'ing sc->nr_scanned
...
This adds tests for double free and cross-cache freeing, which should both
be caught by CONFIG_SLAB_FREELIST_HARDENED.
Link: http://lkml.kernel.org/r/20190530045017.15252-4-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds an x86-specific test for pinned cr4 bits. A successful test
will validate pinning and check the ROP-style call-middle-of-function
defense, if needed. For example, in the case of native_write_cr4()
looking like this:
ffffffff8171bce0 <native_write_cr4>:
ffffffff8171bce0: 48 8b 35 79 46 f2 00 mov 0xf24679(%rip),%rsi
ffffffff8171bce7: 48 09 f7 or %rsi,%rdi
ffffffff8171bcea: 0f 22 e7 mov %rdi,%cr4
...
ffffffff8171bd5a: c3 retq
The UNSET_SMEP test will jump to ffffffff8171bcea (the mov to cr4)
instead of ffffffff8171bce0 (native_write_cr4() entry) to simulate a
direct-call bypass attempt.
Expected successful results:
# echo UNSET_SMEP > /sys/kernel/debug/provoke-crash/DIRECT
# dmesg
[ 79.594433] lkdtm: Performing direct entry UNSET_SMEP
[ 79.596459] lkdtm: trying to clear SMEP normally
[ 79.598406] lkdtm: ok: SMEP did not get cleared
[ 79.599981] lkdtm: trying to clear SMEP with call gadget
[ 79.601810] ------------[ cut here ]------------
[ 79.603421] Attempt to unpin cr4 bits: 100000; bypass attack?!
...
[ 79.650170] ---[ end trace 2452ca0f6126242e ]---
[ 79.650937] lkdtm: ok: SMEP removal was reverted
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While I was able to trick gcc into keeping a pathological recursion,
Clang was not so easily fooled. Instead, switch to using "volatile" and
side-effects to keep the stack variable allocated and to run the function.
Additionally renames "OVERFLOW" to "EXHAUST_STACK" to better describe the
test.
Signed-off-by: Kees Cook <keescook@chromium.org>
Introduce lkdtm tests for NULL pointer dereference: check access or exec
at NULL address, since these errors tend to be reported differently from
the general fault error text. For example from x86:
pr_alert("BUG: unable to handle kernel %s at %px\n",
address < PAGE_SIZE ? "NULL pointer dereference" : "paging request",
(void *)address);
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Kees Cook <keescook@chromium.org>
- Introduces the stackleak gcc plugin ported from grsecurity by Alexander
Popov, with x86 and arm64 support.
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Merge tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull stackleak gcc plugin from Kees Cook:
"Please pull this new GCC plugin, stackleak, for v4.20-rc1. This plugin
was ported from grsecurity by Alexander Popov. It provides efficient
stack content poisoning at syscall exit. This creates a defense
against at least two classes of flaws:
- Uninitialized stack usage. (We continue to work on improving the
compiler to do this in other ways: e.g. unconditional zero init was
proposed to GCC and Clang, and more plugin work has started too).
- Stack content exposure. By greatly reducing the lifetime of valid
stack contents, exposures via either direct read bugs or unknown
cache side-channels become much more difficult to exploit. This
complements the existing buddy and heap poisoning options, but
provides the coverage for stacks.
The x86 hooks are included in this series (which have been reviewed by
Ingo, Dave Hansen, and Thomas Gleixner). The arm64 hooks have already
been merged through the arm64 tree (written by Laura Abbott and
reviewed by Mark Rutland and Will Deacon).
With VLAs having been removed this release, there is no need for
alloca() protection, so it has been removed from the plugin"
* tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
arm64: Drop unneeded stackleak_check_alloca()
stackleak: Allow runtime disabling of kernel stack erasing
doc: self-protection: Add information about STACKLEAK feature
fs/proc: Show STACKLEAK metrics in the /proc file system
lkdtm: Add a test for STACKLEAK
gcc-plugins: Add STACKLEAK plugin for tracking the kernel stack
x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscalls
Introduce an lkdtm test for the STACKLEAK feature: check that the
current task stack is properly erased (filled with STACKLEAK_POISON).
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Tested-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Test whether the kernel WARN()s when, under KERNEL_DS, a bad kernel pointer
is used as "userspace" pointer. Should normally be used in "DIRECT" mode.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: kernel-hardening@lists.openwall.com
Cc: dvyukov@google.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20180828201421.157735-8-jannh@google.com
The LKDTM modules keep expanding, and it's getting weird to have each file
get a prefix. Instead, move to a subdirectory for cleaner handling.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kees Cook
Linus Torvalds
Christophe Leroy
Alexander Popov
Jann Horn