1
Commit Graph

139 Commits

Author SHA1 Message Date
Petr Pavlu
f91f7ac900 refcount: Report UAF for refcount_sub_and_test(0) when counter==0
When a reference counter is at zero and refcount_sub_and_test() is invoked
to subtract zero, the function accepts this request without any warning and
returns true. This behavior does not seem ideal because the counter being
already at zero indicates a use-after-free. Furthermore, returning true by
refcount_sub_and_test() in this case potentially results in a double-free
done by its caller.

Modify the underlying function __refcount_sub_and_test() to warn about this
case as a use-after-free and have it return false to avoid the potential
double-free.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240717130023.5675-1-petr.pavlu@suse.com
Signed-off-by: Kees Cook <kees@kernel.org>
2024-08-05 14:34:23 -07:00
Mark Rutland
51005a59bc lkdtm/bugs: add test for hung smp_call_function_single()
The CONFIG_CSD_LOCK_WAIT_DEBUG option enables debugging of hung
smp_call_function*() calls (e.g. when the target CPU gets stuck within
the callback function). Testing this option requires triggering such
hangs.

This patch adds an lkdtm test with a hung smp_call_function_single()
callback, which can be used to test CONFIG_CSD_LOCK_WAIT_DEBUG and NMI
backtraces (as CONFIG_CSD_LOCK_WAIT_DEBUG will attempt an NMI backtrace
of the hung target CPU).

On arm64 using pseudo-NMI, this looks like:

| # mount -t debugfs none /sys/kernel/debug/
| # echo SMP_CALL_LOCKUP > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry SMP_CALL_LOCKUP
| smp: csd: Detected non-responsive CSD lock (#1) on CPU#1, waiting 5000000176 ns for CPU#00 __lkdtm_SMP_CALL_LOCKUP+0x0/0x8(0x0).
| smp:     csd: CSD lock (#1) handling this request.
| Sending NMI from CPU 1 to CPUs 0:
| NMI backtrace for cpu 0
| CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.9.0-rc4-00001-gfdfd281212ec #1
| Hardware name: linux,dummy-virt (DT)
| pstate: 60401005 (nZCv daif +PAN -UAO -TCO -DIT +SSBS BTYPE=--)
| pc : __lkdtm_SMP_CALL_LOCKUP+0x0/0x8
| lr : __flush_smp_call_function_queue+0x1b0/0x290
| sp : ffff800080003f30
| pmr_save: 00000060
| x29: ffff800080003f30 x28: ffffa4ce961a4900 x27: 0000000000000000
| x26: fff000003fcfa0c0 x25: ffffa4ce961a4900 x24: ffffa4ce959aa140
| x23: ffffa4ce959aa140 x22: 0000000000000000 x21: ffff800080523c40
| x20: 0000000000000000 x19: 0000000000000000 x18: fff05b31aa323000
| x17: fff05b31aa323000 x16: ffff800080000000 x15: 0000330fc3fe6b2c
| x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000279
| x11: 0000000000000040 x10: fff000000302d0a8 x9 : fff000000302d0a0
| x8 : fff0000003400270 x7 : 0000000000000000 x6 : ffffa4ce9451b810
| x5 : 0000000000000000 x4 : fff05b31aa323000 x3 : ffff800080003f30
| x2 : fff05b31aa323000 x1 : ffffa4ce959aa140 x0 : 0000000000000000
| Call trace:
|  __lkdtm_SMP_CALL_LOCKUP+0x0/0x8
|  generic_smp_call_function_single_interrupt+0x14/0x20
|  ipi_handler+0xb8/0x178
|  handle_percpu_devid_irq+0x84/0x130
|  generic_handle_domain_irq+0x2c/0x44
|  gic_handle_irq+0x118/0x240
|  call_on_irq_stack+0x24/0x4c
|  do_interrupt_handler+0x80/0x84
|  el1_interrupt+0x44/0xc0
|  el1h_64_irq_handler+0x18/0x24
|  el1h_64_irq+0x78/0x7c
|  default_idle_call+0x40/0x60
|  do_idle+0x23c/0x2d0
|  cpu_startup_entry+0x38/0x3c
|  kernel_init+0x0/0x1d8
|  start_kernel+0x51c/0x608
|  __primary_switched+0x80/0x88
| CPU: 1 PID: 128 Comm: sh Not tainted 6.9.0-rc4-00001-gfdfd281212ec #1
| Hardware name: linux,dummy-virt (DT)
| Call trace:
|  dump_backtrace+0x90/0xe8
|  show_stack+0x18/0x24
|  dump_stack_lvl+0xac/0xe8
|  dump_stack+0x18/0x24
|  csd_lock_wait_toolong+0x268/0x338
|  smp_call_function_single+0x1dc/0x2f0
|  lkdtm_SMP_CALL_LOCKUP+0xcc/0xfc
|  lkdtm_do_action+0x1c/0x38
|  direct_entry+0xbc/0x14c
|  full_proxy_write+0x60/0xb4
|  vfs_write+0xd0/0x35c
|  ksys_write+0x70/0x104
|  __arm64_sys_write+0x1c/0x28
|  invoke_syscall+0x48/0x114
|  el0_svc_common.constprop.0+0x40/0xe0
|  do_el0_svc+0x1c/0x28
|  el0_svc+0x38/0x108
|  el0t_64_sync_handler+0x120/0x12c
|  el0t_64_sync+0x1a4/0x1a8
| smp: csd: Continued non-responsive CSD lock (#1) on CPU#1, waiting 10000064272 ns for CPU#00 __lkdtm_SMP_CALL_LOCKUP+0x0/0x8(0x0).
| smp:     csd: CSD lock (#1) handling this request.
| smp: csd: Continued non-responsive CSD lock (#1) on CPU#1, waiting 15000064384 ns for CPU#00 __lkdtm_SMP_CALL_LOCKUP+0x0/0x8(0x0).
| smp:     csd: CSD lock (#1) handling this request.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240515120828.375585-1-mark.rutland@arm.com
Signed-off-by: Kees Cook <kees@kernel.org>
2024-06-17 11:17:31 -07:00
Linus Torvalds
ff9a79307f Kbuild updates for v6.10
- Avoid 'constexpr', which is a keyword in C23
 
  - Allow 'dtbs_check' and 'dt_compatible_check' run independently of
    'dt_binding_check'
 
  - Fix weak references to avoid GOT entries in position-independent
    code generation
 
  - Convert the last use of 'optional' property in arch/sh/Kconfig
 
  - Remove support for the 'optional' property in Kconfig
 
  - Remove support for Clang's ThinLTO caching, which does not work with
    the .incbin directive
 
  - Change the semantics of $(src) so it always points to the source
    directory, which fixes Makefile inconsistencies between upstream and
    downstream
 
  - Fix 'make tar-pkg' for RISC-V to produce a consistent package
 
  - Provide reasonable default coverage for objtool, sanitizers, and
    profilers
 
  - Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc.
 
  - Remove the last use of tristate choice in drivers/rapidio/Kconfig
 
  - Various cleanups and fixes in Kconfig
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAmZFlGcVHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsG8voQALC8NtFpduWVfLRj2Qg6Ll/xf1vX
 2igcTJEOFHkeqXLGoT8dTDKLEipUBUvKyguPq66CGwVTe2g6zy/nUSXeVtFrUsIa
 msLTi8FqhqUo5lodNvGMRf8qqmuqcvnXoiQwIocF92jtsFy14bhiFY+n4HfcFNjj
 GOKwqBZYQUwY/VVb090efc7RfS9c7uwABJSBelSoxg3AGZriwjGy7Pw5aSKGgVYi
 inqL1eR6qwPP6z7CgQWM99soP+zwybFZmnQrsD9SniRBI4rtAat8Ih5jQFaSUFUQ
 lk2w0NQBRFN88/uR2IJ2GWuIlQ74WeJ+QnCqVuQ59tV5zw90wqSmLzngfPD057Dv
 JjNuhk0UyXVtpIg3lRtd4810ppNSTe33b9OM4O2H846W/crju5oDRNDHcflUXcwm
 Rmn5ho1rb5QVzDVejJbgwidnUInSgJ9PZcvXQ/RJVZPhpgsBzAY9pQexG1G3hviw
 y9UDrt6KP6bF9tHjmolmtdIes9Pj0c4dN6/Rdj4HS4hIQ/GDar0tnwvOvtfUctNL
 orJlBsA6GeMmDVXKkR0ytOCWRYqWWbyt8g70RVKQJfuHX7/hGyAQPaQ2/u4mQhC2
 aevYfbNJMj0VDfGz81HDBKFtkc5n+Ite8l157dHEl2LEabkOkRdNVcn7SNbOvZmd
 ZCSnZ31h7woGfNho
 =D5B/
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Avoid 'constexpr', which is a keyword in C23

 - Allow 'dtbs_check' and 'dt_compatible_check' run independently of
   'dt_binding_check'

 - Fix weak references to avoid GOT entries in position-independent code
   generation

 - Convert the last use of 'optional' property in arch/sh/Kconfig

 - Remove support for the 'optional' property in Kconfig

 - Remove support for Clang's ThinLTO caching, which does not work with
   the .incbin directive

 - Change the semantics of $(src) so it always points to the source
   directory, which fixes Makefile inconsistencies between upstream and
   downstream

 - Fix 'make tar-pkg' for RISC-V to produce a consistent package

 - Provide reasonable default coverage for objtool, sanitizers, and
   profilers

 - Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc.

 - Remove the last use of tristate choice in drivers/rapidio/Kconfig

 - Various cleanups and fixes in Kconfig

* tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (46 commits)
  kconfig: use sym_get_choice_menu() in sym_check_prop()
  rapidio: remove choice for enumeration
  kconfig: lxdialog: remove initialization with A_NORMAL
  kconfig: m/nconf: merge two item_add_str() calls
  kconfig: m/nconf: remove dead code to display value of bool choice
  kconfig: m/nconf: remove dead code to display children of choice members
  kconfig: gconf: show checkbox for choice correctly
  kbuild: use GCOV_PROFILE and KCSAN_SANITIZE in scripts/Makefile.modfinal
  Makefile: remove redundant tool coverage variables
  kbuild: provide reasonable defaults for tool coverage
  modules: Drop the .export_symbol section from the final modules
  kconfig: use menu_list_for_each_sym() in sym_check_choice_deps()
  kconfig: use sym_get_choice_menu() in conf_write_defconfig()
  kconfig: add sym_get_choice_menu() helper
  kconfig: turn defaults and additional prompt for choice members into error
  kconfig: turn missing prompt for choice members into error
  kconfig: turn conf_choice() into void function
  kconfig: use linked list in sym_set_changed()
  kconfig: gconf: use MENU_CHANGED instead of SYMBOL_CHANGED
  kconfig: gconf: remove debug code
  ...
2024-05-18 12:39:20 -07:00
Masahiro Yamada
7f7f6f7ad6 Makefile: remove redundant tool coverage variables
Now Kbuild provides reasonable defaults for objtool, sanitizers, and
profilers.

Remove redundant variables.

Note:

This commit changes the coverage for some objects:

  - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV
  - include arch/sparc/vdso/vdso-image-*.o into UBSAN
  - include arch/sparc/vdso/vma.o into UBSAN
  - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
  - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
  - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV
  - include arch/x86/entry/vdso/vma.o into GCOV, KCOV
  - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV

I believe these are positive effects because all of them are kernel
space objects.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Roberto Sassu <roberto.sassu@huawei.com>
2024-05-14 23:35:48 +09:00
Kees Cook
fb28a8862d lkdtm: Disable CFI checking for perms functions
The EXEC_RODATA test plays a lot of tricks to live in the .rodata section,
and once again ran into objtool's (completely reasonable) assumptions
that executable code should live in an executable section. However, this
manifested only under CONFIG_CFI_CLANG=y, as one of the .cfi_sites was
pointing into the .rodata section.

Since we're testing non-CFI execution properties in perms.c (and
rodata.c), we can disable CFI for the involved functions, and remove the
CFI arguments from rodata.c entirely.

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202308301532.d7acf63e-oliver.sang@intel.com
Fixes: 6342a20efb ("objtool: Add elf_create_section_pair()")
Link: https://lore.kernel.org/r/20240430234953.work.760-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-05-01 12:37:42 -07:00
Nathan Chancellor
231dc3f0c9 lkdtm/bugs: Improve warning message for compilers without counted_by support
The current message for telling the user that their compiler does not
support the counted_by attribute in the FAM_BOUNDS test does not make
much sense either grammatically or semantically. Fix it to make it
correct in both aspects.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20240321-lkdtm-improve-lack-of-counted_by-msg-v1-1-0fbf7481a29c@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-03-22 16:25:31 -07:00
Linus Torvalds
0ea680eda6 slab changes for 6.9
-----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCAAdFiEEe7vIQRWZI0iWSE3xu+CwddJFiJoFAmXwH0wACgkQu+CwddJF
 iJq3HAf6A/0m0pSr0QDcwjM8D7TVYQJ+Z/jPC6Mj+HfTcF8Otrgk8c0M6EsHGIGF
 GQNnYJRKmBla3mpVFvDtsVZuiakEtRLCpoP5n23s8p8gY9ibJcl6bpn9NaMVMKrq
 kBnhQ9VdLAgKVcTH8wz6jJqdWiZ7W4jGH5NWO+nr+r0H7vay7jfB0+tur1NO8J09
 HE5I76XE6ArRvaKYxvsZmOx1pihSmsJ7CerXN6Y8U5qcuxNXdUO/9rf+uv5llDIV
 gl54UAU79koZ9k88t5AiSKO2IZVhBgC/j66ds9MRRAFCf/ldxUtJIlsHTOnumfmy
 FApqwtR0MYNPeMPZpzogQbv58oOcNw==
 =XDxn
 -----END PGP SIGNATURE-----

Merge tag 'slab-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab updates from Vlastimil Babka:

 - Freelist loading optimization (Chengming Zhou)

   When the per-cpu slab is depleted and a new one loaded from the cpu
   partial list, optimize the loading to avoid an irq enable/disable
   cycle. This results in a 3.5% performance improvement on the "perf
   bench sched messaging" test.

 - Kernel boot parameters cleanup after SLAB removal (Xiongwei Song)

   Due to two different main slab implementations we've had boot
   parameters prefixed either slab_ and slub_ with some later becoming
   an alias as both implementations gained the same functionality (i.e.
   slab_nomerge vs slub_nomerge). In order to eventually get rid of the
   implementation-specific names, the canonical and documented
   parameters are now all prefixed slab_ and the slub_ variants become
   deprecated but still working aliases.

 - SLAB_ kmem_cache creation flags cleanup (Vlastimil Babka)

   The flags had hardcoded #define values which became tedious and
   error-prone when adding new ones. Assign the values via an enum that
   takes care of providing unique bit numbers. Also deprecate
   SLAB_MEM_SPREAD which was only used by SLAB, so it's a no-op since
   SLAB removal. Assign it an explicit zero value. The removals of the
   flag usage are handled independently in the respective subsystems,
   with a final removal of any leftover usage planned for the next
   release.

 - Misc cleanups and fixes (Chengming Zhou, Xiaolei Wang, Zheng Yejian)

   Includes removal of unused code or function parameters and a fix of a
   memleak.

* tag 'slab-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  slab: remove PARTIAL_NODE slab_state
  mm, slab: remove memcg_from_slab_obj()
  mm, slab: remove the corner case of inc_slabs_node()
  mm/slab: Fix a kmemleak in kmem_cache_destroy()
  mm, slab, kasan: replace kasan_never_merge() with SLAB_NO_MERGE
  mm, slab: use an enum to define SLAB_ cache creation flags
  mm, slab: deprecate SLAB_MEM_SPREAD flag
  mm, slab: fix the comment of cpu partial list
  mm, slab: remove unused object_size parameter in kmem_cache_flags()
  mm/slub: remove parameter 'flags' in create_kmalloc_caches()
  mm/slub: remove unused parameter in next_freelist_entry()
  mm/slub: remove full list manipulation for non-debug slab
  mm/slub: directly load freelist from cpu partial slab in the likely case
  mm/slub: make the description of slab_min_objects helpful in doc
  mm/slub: replace slub_$params with slab_$params in slub.rst
  mm/slub: unify all sl[au]b parameters with "slab_$param"
  Documentation: kernel-parameters: remove noaliencache
2024-03-12 20:14:54 -07:00
Douglas Anderson
735b7636d1 lkdtm/bugs: In lkdtm_HUNG_TASK() use BUG(), not BUG_ON(1)
In commit edb6538da3df ("lkdtm/bugs: Adjust lkdtm_HUNG_TASK() to avoid
tail call optimization") we marked lkdtm_HUNG_TASK() as
__noreturn. The compiler gets unhappy if it thinks a __noreturn
function might return, so there's a BUG_ON(1) at the end. Any human
can see that the function won't return and the compiler can figure
that out too. Except when it can't.

The MIPS architecture defines HAVE_ARCH_BUG_ON and defines its own
version of BUG_ON(). The MIPS version of BUG_ON() is not a macro but
is instead an inline function. Apparently this prevents the compiler
from realizing that the condition to BUG_ON() is constant and that the
function will never return.

Let's change the BUG_ON(1) to just BUG(), which it should have been to
begin with. The only reason I used BUG_ON(1) to begin with was because
I was used to using WARN_ON(1) when writing test code and WARN() and
BUG() are oddly inconsistent in this manner. :-/

Fixes: edb6538da3df ("lkdtm/bugs: Adjust lkdtm_HUNG_TASK() to avoid tail call optimization")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202401262204.wUFKRYZF-lkp@intel.com/
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240126072852.1.Ib065e528a8620474a72f15baa2feead1f3d89865@changeid
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-02-01 09:44:07 -08:00
Douglas Anderson
6dde3569b8 lkdtm/bugs: Adjust lkdtm_HUNG_TASK() to avoid tail call optimization
When testing with lkdtm_HUNG_TASK() and looking at the output, I
expected to see lkdtm_HUNG_TASK() in the stack crawl but it wasn't
there. Instead, the top function on at least some devices was
schedule() due to tail call optimization.

Let's do two things to help here:
1. We'll mark this as "__noreturn". On GCC at least this is documented
   to prevent tail call optimization. The docs [1] say "In order to
   preserve backtraces, GCC will never turn calls to noreturn
   functions into tail calls."
2. We'll add a BUG_ON(1) at the end which means that schedule() is no
   longer a tail call. Note that this is potentially important because
   if we _did_ end up returning from schedule() due to some weird
   issue then we'd potentially be violating the "noreturn" that we
   told the compiler about. BUG is the right thing to do here.

[1] https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240122164935.2.I26e8f68c312824fcc80c19d4e91de2d2bef958f0@changeid
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-02-01 09:44:07 -08:00
Douglas Anderson
84022cff50 lkdtm: Make lkdtm_do_action() return to avoid tail call optimization
The comments for lkdtm_do_action() explicitly call out that it
shouldn't be inlined because we want it to show up in stack
crawls. However, at least with some compilers / options it's still
vanishing due to tail call optimization. Let's add a return value to
the function to make it harder for the compiler to do tail call
optimization here.

Now that we have a return value, we can actually use it in the
callers, which is a minor improvement in the code.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240122164935.1.I345e485f36babad76370c59659a706723750d950@changeid
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-02-01 09:44:07 -08:00
Xiongwei Song
671776b32b mm/slub: unify all sl[au]b parameters with "slab_$param"
Since the SLAB allocator has been removed, so we can clean up the
sl[au]b_$params. With only one slab allocator left, it's better to use the
generic "slab" term instead of "slub" which is an implementation detail,
which is pointed out by Vlastimil Babka. For more information please see
[1]. Hence, we are going to use "slab_$param" as the primary prefix.

This patch is changing the following slab parameters
- slub_max_order
- slub_min_order
- slub_min_objects
- slub_debug
to
- slab_max_order
- slab_min_order
- slab_min_objects
- slab_debug
as the primary slab parameters for all references of them in docs and
comments. But this patch won't change variables and functions inside
slub as we will have wider slub/slab change.

Meanwhile, "slub_$params" can also be passed by command line, which is
to keep backward compatibility. Also mark all "slub_$params" as legacy.

Remove the separate descriptions for slub_[no]merge, append legacy tip
for them at the end of descriptions of slab_[no]merge.

[1] https://lore.kernel.org/linux-mm/7512b350-4317-21a0-fab3-4101bc4d8f7a@suse.cz/

Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-01-22 10:31:08 +01:00
Stephen Boyd
aabf7c37df lkdtm: Add kfence read after free crash type
Add the ability to allocate memory from kfence and trigger a read after
free on that memory to validate that kfence is working properly. This is
used by ChromeOS integration tests to validate that kfence errors can be
collected on user devices and parsed properly.

Cc: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: kasan-dev@googlegroups.com
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20231129214413.3156334-1-swboyd@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-12-01 09:51:43 -08:00
Linus Torvalds
d46392bbf5 RISC-V Patches for the 6.7 Merge Window, Part 1
* Support for cbo.zero in userspace.
 * Support for CBOs on ACPI-based systems.
 * A handful of improvements for the T-Head cache flushing ops.
 * Support for software shadow call stacks.
 * Various cleanups and fixes.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCAAxFiEEKzw3R0RoQ7JKlDp6LhMZ81+7GIkFAmVJAJoTHHBhbG1lckBk
 YWJiZWx0LmNvbQAKCRAuExnzX7sYiWZrD/9ECV/0tuX5LbS56kA0ElkwiakyIVGu
 ZVuF26yGJ6w+XvwnHPhqKNVN0ReYR6s6CwH1WpHI5Du9QHZGQU3DKJ43dFMTP3Dn
 dQFli7QJ+tsNo1nre8NZWKj5Ac+Cu906F794qM0q0XrZmyb9DY3ojVYJAYy+dtoo
 /9gwbB7P0GLyDlURLn48oQyz36WQW3CkL5Jkfu+uYwnFe9DAFtfakIKq5mLlNuaH
 PgUk8pAVhSy2GdPOGFtnFFhdXMrTjpgxdo62ZIZC0lbsts26Dxp95oUygqMg51Iy
 ilaXkA2U1c1+gFQNpEove7BVZa5708Kaj6RLQ3/kAJblAzibszwQvIWlWOh7RVni
 3GQAS7/0D0+0cjDwXdWaPIaFFzLfi3bDxRYkc7n59p6nOz+GrxnSNsRPQJGgYxeU
 oTtJfaqWKntm72iutiHmXgx/pvAxWOHpqDnSTlDdtjvgzXCplqBbxZFF/azj30o5
 jplNW5YvdvD9fviYMAoGSOz03IwDeZF5rMlAhqu6vXlyD2//mID82yw/hBluIA3+
 /hLo5QfTLiUGs9nnijxMcfoyusN6AXsJOxwYdAJCIuJOr78YUj0S974gd9KvJXma
 KedrwRVwW7KE7CwY1jhrWBsZEpzl8YrtpMDN47y4gRtDZN8XJMQ+lHqd+BHT/DUO
 TGUCYi5xvr6Vlw==
 =hKWl
 -----END PGP SIGNATURE-----

Merge tag 'riscv-for-linus-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - Support for cbo.zero in userspace

 - Support for CBOs on ACPI-based systems

 - A handful of improvements for the T-Head cache flushing ops

 - Support for software shadow call stacks

 - Various cleanups and fixes

* tag 'riscv-for-linus-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (31 commits)
  RISC-V: hwprobe: Fix vDSO SIGSEGV
  riscv: configs: defconfig: Enable configs required for RZ/Five SoC
  riscv: errata: prefix T-Head mnemonics with th.
  riscv: put interrupt entries into .irqentry.text
  riscv: mm: Update the comment of CONFIG_PAGE_OFFSET
  riscv: Using TOOLCHAIN_HAS_ZIHINTPAUSE marco replace zihintpause
  riscv/mm: Fix the comment for swap pte format
  RISC-V: clarify the QEMU workaround in ISA parser
  riscv: correct pt_level name via pgtable_l5/4_enabled
  RISC-V: Provide pgtable_l5_enabled on rv32
  clocksource: timer-riscv: Increase rating of clock_event_device for Sstc
  clocksource: timer-riscv: Don't enable/disable timer interrupt
  lkdtm: Fix CFI_BACKWARD on RISC-V
  riscv: Use separate IRQ shadow call stacks
  riscv: Implement Shadow Call Stack
  riscv: Move global pointer loading to a macro
  riscv: Deduplicate IRQ stack switching
  riscv: VMAP_STACK overflow detection thread-safe
  RISC-V: cacheflush: Initialize CBO variables on ACPI systems
  RISC-V: ACPI: RHCT: Add function to get CBO block sizes
  ...
2023-11-08 09:21:18 -08:00
Sami Tolvanen
245561ba6d
lkdtm: Fix CFI_BACKWARD on RISC-V
On RISC-V, the return address is before the current frame pointer,
unlike on most other architectures. Use the correct offset on RISC-V
to fix the CFI_BACKWARD test.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230927224757.1154247-14-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-10-27 14:43:10 -07:00
Mark Rutland
eac80dd4bc lkdtm/bugs: add test for panic() with stuck secondary CPUs
Upon a panic() the kernel will use either smp_send_stop() or
crash_smp_send_stop() to attempt to stop secondary CPUs via an IPI,
which may or may not be an NMI. Generally it's preferable that this is an
NMI so that CPUs can be stopped in as many situations as possible, but
it's not always possible to provide an NMI, and there are cases where
CPUs may be unable to handle the NMI regardless.

This patch adds a test for panic() where all other CPUs are stuck with
interrupts disabled, which can be used to check whether the kernel
gracefully handles CPUs failing to respond to a stop, and whether NMIs
actually work to stop CPUs.

For example, on arm64 *without* an NMI, this results in:

| # echo PANIC_STOP_IRQOFF > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry PANIC_STOP_IRQOFF
| Kernel panic - not syncing: panic stop irqoff test
| CPU: 2 PID: 24 Comm: migration/2 Not tainted 6.5.0-rc3-00077-ge6c782389895-dirty #4
| Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
| Stopper: multi_cpu_stop+0x0/0x1a0 <- stop_machine_cpuslocked+0x158/0x1a4
| Call trace:
|  dump_backtrace+0x94/0xec
|  show_stack+0x18/0x24
|  dump_stack_lvl+0x74/0xc0
|  dump_stack+0x18/0x24
|  panic+0x358/0x3e8
|  lkdtm_PANIC+0x0/0x18
|  multi_cpu_stop+0x9c/0x1a0
|  cpu_stopper_thread+0x84/0x118
|  smpboot_thread_fn+0x224/0x248
|  kthread+0x114/0x118
|  ret_from_fork+0x10/0x20
| SMP: stopping secondary CPUs
| SMP: failed to stop secondary CPUs 0-3
| Kernel Offset: 0x401cf3490000 from 0xffff80008000000c0
| PHYS_OFFSET: 0x40000000
| CPU features: 0x00000000,68c167a1,cce6773f
| Memory Limit: none
| ---[ end Kernel panic - not syncing: panic stop irqoff test ]---

Note the "failed to stop secondary CPUs 0-3" message.

On arm64 *with* an NMI, this results in:

| # echo PANIC_STOP_IRQOFF > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry PANIC_STOP_IRQOFF
| Kernel panic - not syncing: panic stop irqoff test
| CPU: 1 PID: 19 Comm: migration/1 Not tainted 6.5.0-rc3-00077-ge6c782389895-dirty #4
| Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
| Stopper: multi_cpu_stop+0x0/0x1a0 <- stop_machine_cpuslocked+0x158/0x1a4
| Call trace:
|  dump_backtrace+0x94/0xec
|  show_stack+0x18/0x24
|  dump_stack_lvl+0x74/0xc0
|  dump_stack+0x18/0x24
|  panic+0x358/0x3e8
|  lkdtm_PANIC+0x0/0x18
|  multi_cpu_stop+0x9c/0x1a0
|  cpu_stopper_thread+0x84/0x118
|  smpboot_thread_fn+0x224/0x248
|  kthread+0x114/0x118
|  ret_from_fork+0x10/0x20
| SMP: stopping secondary CPUs
| Kernel Offset: 0x55a9c0bc0000 from 0xffff800080000000
| PHYS_OFFSET: 0x40000000
| CPU features: 0x00000000,68c167a1,fce6773f
| Memory Limit: none
| ---[ end Kernel panic - not syncing: panic stop irqoff test ]---

Note the absence of a "failed to stop secondary CPUs" message, since we
don't log anything when secondary CPUs are successfully stopped.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20230921161634.4063233-1-mark.rutland@arm.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-09-28 16:39:08 -07:00
Kees Cook
5d207e83ca lkdtm: Add FAM_BOUNDS test for __counted_by
Add new CONFIG_UBSAN_BOUNDS test for __counted_by attribute.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-08-17 16:46:35 -07:00
Marco Elver
aebc7b0d8d list: Introduce CONFIG_LIST_HARDENED
Numerous production kernel configs (see [1, 2]) are choosing to enable
CONFIG_DEBUG_LIST, which is also being recommended by KSPP for hardened
configs [3]. The motivation behind this is that the option can be used
as a security hardening feature (e.g. CVE-2019-2215 and CVE-2019-2025
are mitigated by the option [4]).

The feature has never been designed with performance in mind, yet common
list manipulation is happening across hot paths all over the kernel.

Introduce CONFIG_LIST_HARDENED, which performs list pointer checking
inline, and only upon list corruption calls the reporting slow path.

To generate optimal machine code with CONFIG_LIST_HARDENED:

  1. Elide checking for pointer values which upon dereference would
     result in an immediate access fault (i.e. minimal hardening
     checks).  The trade-off is lower-quality error reports.

  2. Use the __preserve_most function attribute (available with Clang,
     but not yet with GCC) to minimize the code footprint for calling
     the reporting slow path. As a result, function size of callers is
     reduced by avoiding saving registers before calling the rarely
     called reporting slow path.

     Note that all TUs in lib/Makefile already disable function tracing,
     including list_debug.c, and __preserve_most's implied notrace has
     no effect in this case.

  3. Because the inline checks are a subset of the full set of checks in
     __list_*_valid_or_report(), always return false if the inline
     checks failed.  This avoids redundant compare and conditional
     branch right after return from the slow path.

As a side-effect of the checks being inline, if the compiler can prove
some condition to always be true, it can completely elide some checks.

Since DEBUG_LIST is functionally a superset of LIST_HARDENED, the
Kconfig variables are changed to reflect that: DEBUG_LIST selects
LIST_HARDENED, whereas LIST_HARDENED itself has no dependency on
DEBUG_LIST.

Running netperf with CONFIG_LIST_HARDENED (using a Clang compiler with
"preserve_most") shows throughput improvements, in my case of ~7% on
average (up to 20-30% on some test cases).

Link: https://r.android.com/1266735 [1]
Link: https://gitlab.archlinux.org/archlinux/packaging/packages/linux/-/blob/main/config [2]
Link: https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project/Recommended_Settings [3]
Link: https://googleprojectzero.blogspot.com/2019/11/bad-binder-android-in-wild-exploit.html [4]
Signed-off-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20230811151847.1594958-3-elver@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-08-15 14:57:25 -07:00
Linus Torvalds
44aeec836d Char/Misc and other driver subsystem updates for 6.5-rc1
Here is the big set of char/misc and other driver subsystem updates for
 6.5-rc1.
 
 Lots of different, tiny, stuff in here, from a range of smaller driver
 subsystems, including pulls from some substems directly:
   - IIO driver updates and additions
   - W1 driver updates and fixes (and a new maintainer!)
   - FPGA driver updates and fixes
   - Counter driver updates
   - Extcon driver updates
   - Interconnect driver updates
   - Coresight driver updates
   - mfd tree tag merge needed for other updates
 on top of that, lots of small driver updates as patches, including:
   - static const updates for class structures
   - nvmem driver updates
   - pcmcia driver fix
   - lots of other small driver updates and fixes
 
 All of these have been in linux-next for a while with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 
 iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCZKKNMw8cZ3JlZ0Brcm9h
 aC5jb20ACgkQMUfUDdst+ylhlQCfZrtz8RIbau8zbzh/CKpKBOmvHp4An3V64hbz
 recBPLH0ZACKl0wPl4iZ
 =A83A
 -----END PGP SIGNATURE-----

Merge tag 'char-misc-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull Char/Misc updates from Greg KH:
 "Here is the big set of char/misc and other driver subsystem updates
  for 6.5-rc1.

  Lots of different, tiny, stuff in here, from a range of smaller driver
  subsystems, including pulls from some substems directly:

   - IIO driver updates and additions

   - W1 driver updates and fixes (and a new maintainer!)

   - FPGA driver updates and fixes

   - Counter driver updates

   - Extcon driver updates

   - Interconnect driver updates

   - Coresight driver updates

   - mfd tree tag merge needed for other updates on top of that, lots of
     small driver updates as patches, including:

   - static const updates for class structures

   - nvmem driver updates

   - pcmcia driver fix

   - lots of other small driver updates and fixes

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'char-misc-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (243 commits)
  bsr: fix build problem with bsr_class static cleanup
  comedi: make all 'class' structures const
  char: xillybus: make xillybus_class a static const structure
  xilinx_hwicap: make icap_class a static const structure
  virtio_console: make port class a static const structure
  ppdev: make ppdev_class a static const structure
  char: misc: make misc_class a static const structure
  /dev/mem: make mem_class a static const structure
  char: lp: make lp_class a static const structure
  dsp56k: make dsp56k_class a static const structure
  bsr: make bsr_class a static const structure
  oradax: make 'cl' a static const structure
  hwtracing: hisi_ptt: Fix potential sleep in atomic context
  hwtracing: hisi_ptt: Advertise PERF_PMU_CAP_NO_EXCLUDE for PTT PMU
  hwtracing: hisi_ptt: Export available filters through sysfs
  hwtracing: hisi_ptt: Add support for dynamically updating the filter list
  hwtracing: hisi_ptt: Factor out filter allocation and release operation
  samples: pfsm: add CC_CAN_LINK dependency
  misc: fastrpc: check return value of devm_kasprintf()
  coresight: dummy: Update type of mode parameter in dummy_{sink,source}_enable()
  ...
2023-07-03 12:46:47 -07:00
Linus Torvalds
582c161cf3 hardening updates for v6.5-rc1
- Fix KMSAN vs FORTIFY in strlcpy/strlcat (Alexander Potapenko)
 
 - Convert strreplace() to return string start (Andy Shevchenko)
 
 - Flexible array conversions (Arnd Bergmann, Wyes Karny, Kees Cook)
 
 - Add missing function prototypes seen with W=1 (Arnd Bergmann)
 
 - Fix strscpy() kerndoc typo (Arne Welzel)
 
 - Replace strlcpy() with strscpy() across many subsystems which were
   either Acked by respective maintainers or were trivial changes that
   went ignored for multiple weeks (Azeem Shaikh)
 
 - Remove unneeded cc-option test for UBSAN_TRAP (Nick Desaulniers)
 
 - Add KUnit tests for strcat()-family
 
 - Enable KUnit tests of FORTIFY wrappers under UML
 
 - Add more complete FORTIFY protections for strlcat()
 
 - Add missed disabling of FORTIFY for all arch purgatories.
 
 - Enable -fstrict-flex-arrays=3 globally
 
 - Tightening UBSAN_BOUNDS when using GCC
 
 - Improve checkpatch to check for strcpy, strncpy, and fake flex arrays
 
 - Improve use of const variables in FORTIFY
 
 - Add requested struct_size_t() helper for types not pointers
 
 - Add __counted_by macro for annotating flexible array size members
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmSbftQWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJj0MD/9X9jzJzCmsAU+yNldeoAzC84Sk
 GVU3RBxGcTNysL1gZXynkIgigw7DWc4htMGeSABHHwQRVP65JCH1Kw/VqIkyumbx
 9LdX6IklMJb4pRT4PVU3azebV4eNmSjlur2UxMeW54Czm91/6I8RHbJOyAPnOUmo
 2oomGdP/hpEHtKR7hgy8Axc6w5ySwQixh2V5sVZG3VbvCS5WKTmTXbs6puuRT5hz
 iHt7v+7VtEg/Qf1W7J2oxfoghvVBsaRrSLrExWT/oZYh1ZxM7DsCAAoG/IsDgHGA
 9LBXiRECgAFThbHVxLvvKZQMXdVk0i8iXLX43XMKC0wTA+NTyH7wlcQQ4RWNMuo8
 sfA9Qm9gMArXaf64aymr3Uwn20Zan0391HdlbhOJZAE6v3PPJbleUnM58AzD2d3r
 5Lz6AIFBxDImy+3f9iDWgacCT5/PkeiXTHzk9QnKhJyKKtRA58XJxj4q2+rPnGJP
 n4haXqoxD5FJbxdXiGKk31RS0U5HBug7wkOcUrTqDHUbc/QNU2b7dxTKUx+zYtCU
 uV5emPzpF4H4z+91WpO47n9gkMAfwV0lt9S2dwS8pxsgqctbmIan+Jgip7rsqZ2G
 OgLXBsb43eEs+6WgO8tVt/ZHYj9ivGMdrcNcsIfikzNs/xweUJ53k2xSEn2xEa5J
 cwANDmkL6QQK7yfeeg==
 =s0j1
 -----END PGP SIGNATURE-----

Merge tag 'hardening-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening updates from Kees Cook:
 "There are three areas of note:

  A bunch of strlcpy()->strscpy() conversions ended up living in my tree
  since they were either Acked by maintainers for me to carry, or got
  ignored for multiple weeks (and were trivial changes).

  The compiler option '-fstrict-flex-arrays=3' has been enabled
  globally, and has been in -next for the entire devel cycle. This
  changes compiler diagnostics (though mainly just -Warray-bounds which
  is disabled) and potential UBSAN_BOUNDS and FORTIFY _warning_
  coverage. In other words, there are no new restrictions, just
  potentially new warnings. Any new FORTIFY warnings we've seen have
  been fixed (usually in their respective subsystem trees). For more
  details, see commit df8fc4e934.

  The under-development compiler attribute __counted_by has been added
  so that we can start annotating flexible array members with their
  associated structure member that tracks the count of flexible array
  elements at run-time. It is possible (likely?) that the exact syntax
  of the attribute will change before it is finalized, but GCC and Clang
  are working together to sort it out. Any changes can be made to the
  macro while we continue to add annotations.

  As an example of that last case, I have a treewide commit waiting with
  such annotations found via Coccinelle:

    https://git.kernel.org/linus/adc5b3cb48a049563dc673f348eab7b6beba8a9b

  Also see commit dd06e72e68 for more details.

  Summary:

   - Fix KMSAN vs FORTIFY in strlcpy/strlcat (Alexander Potapenko)

   - Convert strreplace() to return string start (Andy Shevchenko)

   - Flexible array conversions (Arnd Bergmann, Wyes Karny, Kees Cook)

   - Add missing function prototypes seen with W=1 (Arnd Bergmann)

   - Fix strscpy() kerndoc typo (Arne Welzel)

   - Replace strlcpy() with strscpy() across many subsystems which were
     either Acked by respective maintainers or were trivial changes that
     went ignored for multiple weeks (Azeem Shaikh)

   - Remove unneeded cc-option test for UBSAN_TRAP (Nick Desaulniers)

   - Add KUnit tests for strcat()-family

   - Enable KUnit tests of FORTIFY wrappers under UML

   - Add more complete FORTIFY protections for strlcat()

   - Add missed disabling of FORTIFY for all arch purgatories.

   - Enable -fstrict-flex-arrays=3 globally

   - Tightening UBSAN_BOUNDS when using GCC

   - Improve checkpatch to check for strcpy, strncpy, and fake flex
     arrays

   - Improve use of const variables in FORTIFY

   - Add requested struct_size_t() helper for types not pointers

   - Add __counted_by macro for annotating flexible array size members"

* tag 'hardening-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (54 commits)
  netfilter: ipset: Replace strlcpy with strscpy
  uml: Replace strlcpy with strscpy
  um: Use HOST_DIR for mrproper
  kallsyms: Replace all non-returning strlcpy with strscpy
  sh: Replace all non-returning strlcpy with strscpy
  of/flattree: Replace all non-returning strlcpy with strscpy
  sparc64: Replace all non-returning strlcpy with strscpy
  Hexagon: Replace all non-returning strlcpy with strscpy
  kobject: Use return value of strreplace()
  lib/string_helpers: Change returned value of the strreplace()
  jbd2: Avoid printing outside the boundary of the buffer
  checkpatch: Check for 0-length and 1-element arrays
  riscv/purgatory: Do not use fortified string functions
  s390/purgatory: Do not use fortified string functions
  x86/purgatory: Do not use fortified string functions
  acpi: Replace struct acpi_table_slit 1-element array with flex-array
  clocksource: Replace all non-returning strlcpy with strscpy
  string: use __builtin_memcpy() in strlcpy/strlcat
  staging: most: Replace all non-returning strlcpy with strscpy
  drm/i2c: tda998x: Replace all non-returning strlcpy with strscpy
  ...
2023-06-27 21:24:18 -07:00
Peter Zijlstra
4a03aa3443 lkdtm: Avoid objtool/ibt warning
For certain configs objtool will complain like:

  vmlinux.o: warning: objtool: lkdtm_UNSET_SMEP+0x1c3: relocation to !ENDBR: native_write_cr4+0x41

What happens is that GCC optimizes the loop:

        insn = (unsigned char *)native_write_cr4;
        for (i = 0; i < MOV_CR4_DEPTH; i++)

to read something like:

        for (insn = (unsigned char *)native_write_cr4;
             insn < (unsigned char *)native_write_cr4 + MOV_CR4_DEPTH;
             insn++)

Which then obviously generates the text reference
native_write_cr4+041. Since none of this is a fast path, simply
confuse GCC enough to inhibit this optimization.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/Y3JdgbXRV0MNZ+9h@hirez.programming.kicks-ass.net
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-06-07 09:27:11 -07:00
Yue Zhao
b290df0681 lkdtm: replace ll_rw_block with submit_bh
Function ll_rw_block was removed in commit 79f5978420 ("fs/buffer:
remove ll_rw_block() helper"). There is no unified function to sumbit
read or write buffer in block layer for now. Consider similar sematics,
we can choose submit_bh() to replace ll_rw_block() as predefined crash
point. In submit_bh(), it also takes read or write flag as the first
argument and invoke submit_bio() to submit I/O request to block layer.

Fixes: 79f5978420 ("fs/buffer: remove ll_rw_block() helper")
Signed-off-by: Yue Zhao <findns94@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230503162944.3969-1-findns94@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-31 20:26:57 +01:00
Kees Cook
b45861ed66 lkdtm/bugs: Switch from 1-element array to flexible array
The testing for ARRAY_BOUNDS just wants an uninstrumented array,
and the proper flexible array definition is fine for that.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bill Wendling <morbo@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-05-30 16:42:00 -07:00
Josh Poimboeuf
f571da059f lkdtm/stackleak: Fix noinstr violation
Fixes the following warning:

  vmlinux.o: warning: objtool: check_stackleak_irqoff+0x2b6: call to _printk() leaves .noinstr.text section

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/ee5209f53aa0a62aea58be18f2b78b17606779a6.1681320026.git.jpoimboe@kernel.org
2023-04-14 16:08:26 +02:00
Kees Cook
439a1bcac6 fortify: Use __builtin_dynamic_object_size() when available
Since the commits starting with c37495d625 ("slab: add __alloc_size
attributes for better bounds checking"), the compilers have runtime
allocation size hints available in some places. This was immediately
available to CONFIG_UBSAN_BOUNDS, but CONFIG_FORTIFY_SOURCE needed
updating to explicitly make use of the hints via the associated
__builtin_dynamic_object_size() helper. Detect and use the builtin when
it is available, increasing the accuracy of the mitigation. When runtime
sizes are not available, __builtin_dynamic_object_size() falls back to
__builtin_object_size(), leaving the existing bounds checking unchanged.

Additionally update the VMALLOC_LINEAR_OVERFLOW LKDTM test to make the
hint invisible, otherwise the architectural defense is not exercised
(the buffer overflow is detected in the memset() rather than when it
crosses the edge of the allocation).

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Tom Rix <trix@redhat.com>
Cc: linux-hardening@vger.kernel.org
Cc: llvm@lists.linux.dev
Reviewed-by: Miguel Ojeda <ojeda@kernel.org> # include/linux/compiler_attributes.h
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-01-05 12:08:29 -08:00
Kristina Martsenko
f68022ae0a lkdtm: cfi: Make PAC test work with GCC 7 and 8
The CFI test uses the branch-protection=none compiler attribute to
disable PAC return address protection on a function. While newer GCC
versions support this attribute, older versions (GCC 7 and 8) instead
supported the sign-return-address=none attribute, leading to a build
failure when the test is built with older compilers. Fix it by checking
which attribute is supported and using the correct one.

Fixes: 2e53b877dc ("lkdtm: Add CFI_BACKWARD to test ROP mitigations")
Reported-by: Daniel Díaz <daniel.diaz@linaro.org>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/CAEUSe78kDPxQmQqCWW-_9LCgJDFhAeMoVBFnX9QLx18Z4uT4VQ@mail.gmail.com/
2022-12-14 16:05:09 -08:00
Linus Torvalds
d0989d01c6 hardening updates for v6.1-rc1
Various fixes across several hardening areas:
 
 - loadpin: Fix verity target enforcement (Matthias Kaehlcke).
 
 - zero-call-used-regs: Add missing clobbers in paravirt (Bill Wendling).
 
 - CFI: clean up sparc function pointer type mismatches (Bart Van Assche).
 
 - Clang: Adjust compiler flag detection for various Clang changes (Sami
   Tolvanen, Kees Cook).
 
 - fortify: Fix warnings in arch-specific code in sh, ARM, and xen.
 
 Improvements to existing features:
 
 - testing: improve overflow KUnit test, introduce fortify KUnit test,
   add more coverage to LKDTM tests (Bart Van Assche, Kees Cook).
 
 - overflow: Relax overflow type checking for wider utility.
 
 New features:
 
 - string: Introduce strtomem() and strtomem_pad() to fill a gap in
   strncpy() replacement needs.
 
 - um: Enable FORTIFY_SOURCE support.
 
 - fortify: Enable run-time struct member memcpy() overflow warning.
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmM4chcWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJvq1D/9uKU03RozAOnzhi4gcgRnHZSAK
 oOQOkPwnkUgFU0yOnMkNYOZ7njLnM+CjCN3RJ9SSpD2lrQ23PwLeThAuOzy0brPO
 0iAksIztSF3e5tAyFjtFkjswrY8MSv/TkF0WttTOSOj3lCUcwatF0FBkclCOXtwu
 ILXfG7K8E17r/wsUejN+oMAI42ih/YeVQAZpKRymEEJsK+Lly7OT4uu3fdFWVb1P
 M77eRLI2Vg1eSgMVwv6XdwGakpUdwsboK7do0GGX+JOrhayJoCfY2IpwyPz9ciel
 jsp9OQs8NrlPJMa2sQ7LDl+b5EQl/MtggX3JlQEbLs2LV7gDtYgAWNo6vxCT5Lvd
 zB7TZqIR3lrVjbtw4FAKQ+41bS4VOajk2NB3Mkiy5AfivB+6zKF+P56a+xSoNhOl
 iktpjCEP7bp4oxmTMXpOfmywjh/ZsyoMhQ2ABP7S+JZ5rHUndpPAjjuBetIcHxX2
 28Wlr4aFIF9ff9caasg4sMYXcQMGnuLUlUKngceUbd1umZZRNZ1gaIxYpm9poefm
 qd/lvTIvzn9V8IB8wHVmvafbvDbV88A+2bKJdSUDA352Dt9PvqT7yI0dmbMNliGL
 os+iLPW6Y6x38BxhXax0HR9FEhO3Eq7kLdNdc4J29NvISg8HHaifwNrG41lNwaWL
 cuc6IAjLxiRk3NsUpg==
 =HZ6+
 -----END PGP SIGNATURE-----

Merge tag 'hardening-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull kernel hardening updates from Kees Cook:
 "Most of the collected changes here are fixes across the tree for
  various hardening features (details noted below).

  The most notable new feature here is the addition of the memcpy()
  overflow warning (under CONFIG_FORTIFY_SOURCE), which is the next step
  on the path to killing the common class of "trivially detectable"
  buffer overflow conditions (i.e. on arrays with sizes known at compile
  time) that have resulted in many exploitable vulnerabilities over the
  years (e.g. BleedingTooth).

  This feature is expected to still have some undiscovered false
  positives. It's been in -next for a full development cycle and all the
  reported false positives have been fixed in their respective trees.
  All the known-bad code patterns we could find with Coccinelle are also
  either fixed in their respective trees or in flight.

  The commit message in commit 54d9469bc5 ("fortify: Add run-time WARN
  for cross-field memcpy()") for the feature has extensive details, but
  I'll repeat here that this is a warning _only_, and is not intended to
  actually block overflows (yet). The many patches fixing array sizes
  and struct members have been landing for several years now, and we're
  finally able to turn this on to find any remaining stragglers.

  Summary:

  Various fixes across several hardening areas:

   - loadpin: Fix verity target enforcement (Matthias Kaehlcke).

   - zero-call-used-regs: Add missing clobbers in paravirt (Bill
     Wendling).

   - CFI: clean up sparc function pointer type mismatches (Bart Van
     Assche).

   - Clang: Adjust compiler flag detection for various Clang changes
     (Sami Tolvanen, Kees Cook).

   - fortify: Fix warnings in arch-specific code in sh, ARM, and xen.

  Improvements to existing features:

   - testing: improve overflow KUnit test, introduce fortify KUnit test,
     add more coverage to LKDTM tests (Bart Van Assche, Kees Cook).

   - overflow: Relax overflow type checking for wider utility.

  New features:

   - string: Introduce strtomem() and strtomem_pad() to fill a gap in
     strncpy() replacement needs.

   - um: Enable FORTIFY_SOURCE support.

   - fortify: Enable run-time struct member memcpy() overflow warning"

* tag 'hardening-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (27 commits)
  Makefile.extrawarn: Move -Wcast-function-type-strict to W=1
  hardening: Remove Clang's enable flag for -ftrivial-auto-var-init=zero
  sparc: Unbreak the build
  x86/paravirt: add extra clobbers with ZERO_CALL_USED_REGS enabled
  x86/paravirt: clean up typos and grammaros
  fortify: Convert to struct vs member helpers
  fortify: Explicitly check bounds are compile-time constants
  x86/entry: Work around Clang __bdos() bug
  ARM: decompressor: Include .data.rel.ro.local
  fortify: Adjust KUnit test for modular build
  sh: machvec: Use char[] for section boundaries
  kunit/memcpy: Avoid pathological compile-time string size
  lib: Improve the is_signed_type() kunit test
  LoadPin: Require file with verity root digests to have a header
  dm: verity-loadpin: Only trust verity targets with enforcement
  LoadPin: Fix Kconfig doc about format of file with verity digests
  um: Enable FORTIFY_SOURCE
  lkdtm: Update tests for memcpy() run-time warnings
  fortify: Add run-time WARN for cross-field memcpy()
  fortify: Use SIZE_MAX instead of (size_t)-1
  ...
2022-10-03 17:24:22 -07:00
Sami Tolvanen
607289a7cd treewide: Drop function_nocfi
With -fsanitize=kcfi, we no longer need function_nocfi() as
the compiler won't change function references to point to a
jump table. Remove all implementations and uses of the macro.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220908215504.3686827-14-samitolvanen@google.com
2022-09-26 10:13:14 -07:00
Sami Tolvanen
cf90d03835 lkdtm: Emit an indirect call for CFI tests
Clang can convert the indirect calls in lkdtm_CFI_FORWARD_PROTO into
direct calls. Move the call into a noinline function that accepts the
target address as an argument to ensure the compiler actually emits an
indirect call instead.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220908215504.3686827-8-samitolvanen@google.com
2022-09-26 10:13:13 -07:00
Kees Cook
325bf6d84b lkdtm: Update tests for memcpy() run-time warnings
Clarify the LKDTM FORTIFY tests, and add tests for the mem*() family of
functions, now that run-time checking is distinct.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-09-07 16:37:27 -07:00
Linus Torvalds
228dfe98a3 Char / Misc driver changes for 6.0-rc1
Here is the large set of char and misc and other driver subsystem
 changes for 6.0-rc1.
 
 Highlights include:
 	- large set of IIO driver updates, additions, and cleanups
 	- new habanalabs device support added (loads of register maps
 	  much like GPUs have)
 	- soundwire driver updates
 	- phy driver updates
 	- slimbus driver updates
 	- tiny virt driver fixes and updates
 	- misc driver fixes and updates
 	- interconnect driver updates
 	- hwtracing driver updates
 	- fpga driver updates
 	- extcon driver updates
 	- firmware driver updates
 	- counter driver update
 	- mhi driver fixes and updates
 	- binder driver fixes and updates
 	- speakup driver fixes
 
 Full details are in the long shortlog contents.
 
 All of these have been in linux-next for a while without any reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 
 iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCYup9QQ8cZ3JlZ0Brcm9h
 aC5jb20ACgkQMUfUDdst+ylBKQCfaSuzl9ZP9dTvAw2FPp14oRqXnpoAnicvWAoq
 1vU9Vtq2c73uBVLdZm4m
 =AwP3
 -----END PGP SIGNATURE-----

Merge tag 'char-misc-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char / misc driver updates from Greg KH:
 "Here is the large set of char and misc and other driver subsystem
  changes for 6.0-rc1.

  Highlights include:

   - large set of IIO driver updates, additions, and cleanups

   - new habanalabs device support added (loads of register maps much
     like GPUs have)

   - soundwire driver updates

   - phy driver updates

   - slimbus driver updates

   - tiny virt driver fixes and updates

   - misc driver fixes and updates

   - interconnect driver updates

   - hwtracing driver updates

   - fpga driver updates

   - extcon driver updates

   - firmware driver updates

   - counter driver update

   - mhi driver fixes and updates

   - binder driver fixes and updates

   - speakup driver fixes

  All of these have been in linux-next for a while without any reported
  problems"

* tag 'char-misc-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (634 commits)
  drivers: lkdtm: fix clang -Wformat warning
  char: remove VR41XX related char driver
  misc: Mark MICROCODE_MINOR unused
  spmi: trace: fix stack-out-of-bound access in SPMI tracing functions
  dt-bindings: iio: adc: Add compatible for MT8188
  iio: light: isl29028: Fix the warning in isl29028_remove()
  iio: accel: sca3300: Extend the trigger buffer from 16 to 32 bytes
  iio: fix iio_format_avail_range() printing for none IIO_VAL_INT
  iio: adc: max1027: unlock on error path in max1027_read_single_value()
  iio: proximity: sx9324: add empty line in front of bullet list
  iio: magnetometer: hmc5843: Remove duplicate 'the'
  iio: magn: yas530: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: magnetometer: ak8974: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: veml6030: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: vcnl4035: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: vcnl4000: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr() macros
  iio: light: tsl2591: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr()
  iio: light: tsl2583: Use DEFINE_RUNTIME_DEV_PM_OPS and pm_ptr()
  iio: light: isl29028: Use DEFINE_RUNTIME_DEV_PM_OPS() and pm_ptr()
  iio: light: gp2ap002: Switch to DEFINE_RUNTIME_DEV_PM_OPS and pm_ptr()
  ...
2022-08-04 11:05:48 -07:00
Linus Torvalds
6991a564f5 hardening updates for v5.20-rc1
- Fix Sparse warnings with randomizd kstack (GONG, Ruiqi)
 
 - Replace uintptr_t with unsigned long in usercopy (Jason A. Donenfeld)
 
 - Fix Clang -Wforward warning in LKDTM (Justin Stitt)
 
 - Fix comment to correctly refer to STRICT_DEVMEM (Lukas Bulwahn)
 
 - Introduce dm-verity binding logic to LoadPin LSM (Matthias Kaehlcke)
 
 - Clean up warnings and overflow and KASAN tests (Kees Cook)
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmLoEN4WHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJr19D/0fUvHaOui3+ePqKL1CEN2WOYxK
 Ed/HA0kM7VZnuakS2OoWbHYKurt9wImBkw0EuryNEP4nCBHy5OIyDOmWF7DjWntG
 9agKLW5rRgbKe9STbGZpJ92WWosOcJkgkDVES1/NjWt7ujLiefzcZE85hj2Dt1aQ
 6nF2LlkdGdtsa07hP5CR5bynQxAAxg1R1pLiJCgZRYn1SEFYtjcnBjUMrPUFJAi2
 TNy6ijeG473Oj6V/JiIY88u41KG1fed22SymNj6aQVIjGpH7atn6/ooG076ydAyt
 QEibSyQP/CwkSbyiqVFOq4v4a+hKEB5j5F+iKZBrCnFWNvt8D3tizBYgm1NymNEZ
 VBZdg+UhcoVDwiMNzSaAGvt15Qv0INNkQm9PJoeUGSdXz0Yjf4ghOIeaQc3jm6Of
 tElawmPXxVwRZfNpf5tyPaZFphAPK5EAl35S5mdWinKbAO7Jpz9xqvoyZz9/kygR
 Kd4qyRPrl0YM8SBKFuYt5rFaYfw9wqF7ox7cMmwR+pbEHt7UDqDvkX2fBbpCyXza
 5nJ9PDyvB5SqonIF57RiImXCLKXR6UMJgQvtDGsf+n4hpxL40Nga4pqWY82aQEhj
 SRdQlkFYhI/izIq1kMJNa8IoOONlJzV6i87D8iOW32bI3/SrykRUTvV3ohpMri7V
 UFkXzz8pfqfJ4k4zVA==
 =FRS3
 -----END PGP SIGNATURE-----

Merge tag 'hardening-v5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening updates from Kees Cook:

 - Fix Sparse warnings with randomizd kstack (GONG, Ruiqi)

 - Replace uintptr_t with unsigned long in usercopy (Jason A. Donenfeld)

 - Fix Clang -Wforward warning in LKDTM (Justin Stitt)

 - Fix comment to correctly refer to STRICT_DEVMEM (Lukas Bulwahn)

 - Introduce dm-verity binding logic to LoadPin LSM (Matthias Kaehlcke)

 - Clean up warnings and overflow and KASAN tests (Kees Cook)

* tag 'hardening-v5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  dm: verity-loadpin: Drop use of dm_table_get_num_targets()
  kasan: test: Silence GCC 12 warnings
  drivers: lkdtm: fix clang -Wformat warning
  x86: mm: refer to the intended config STRICT_DEVMEM in a comment
  dm: verity-loadpin: Use CONFIG_SECURITY_LOADPIN_VERITY for conditional compilation
  LoadPin: Enable loading from trusted dm-verity devices
  dm: Add verity helpers for LoadPin
  stack: Declare {randomize_,}kstack_offset to fix Sparse warnings
  lib: overflow: Do not define 64-bit tests on 32-bit
  MAINTAINERS: Add a general "kernel hardening" section
  usercopy: use unsigned long instead of uintptr_t
2022-08-02 14:38:59 -07:00
Justin Stitt
b5276c9244 drivers: lkdtm: fix clang -Wformat warning
When building with Clang we encounter the following warning
(ARCH=hexagon + CONFIG_FRAME_WARN=0):
| ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type
| 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
|                 REC_STACK_SIZE, recur_count);
|                 ^~~~~~~~~~~~~~

Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`
as well as maintain symmetry with `#define REC_STACK_SIZE
(_AC(CONFIG_FRAME_WARN, UL) / 2)`.

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Fixes: 24cccab42c ("lkdtm/bugs: Adjust recursion test to avoid elision")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20220721215706.4153027-1-justinstitt@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-28 16:20:36 +02:00
Justin Stitt
b4909252da drivers: lkdtm: fix clang -Wformat warning
When building with Clang we encounter the following warning
(ARCH=hexagon + CONFIG_FRAME_WARN=0):
| ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type
| 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
|                 REC_STACK_SIZE, recur_count);
|                 ^~~~~~~~~~~~~~

Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`
as well as maintain symmetry with `#define REC_STACK_SIZE
(_AC(CONFIG_FRAME_WARN, UL) / 2)`.

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Fixes: 24cccab42c ("lkdtm/bugs: Adjust recursion test to avoid elision")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220721215706.4153027-1-justinstitt@google.com
2022-07-27 12:16:17 -07:00
Josh Poimboeuf
efc72a665a lkdtm: Disable return thunks in rodata.c
The following warning was seen:

  WARNING: CPU: 0 PID: 0 at arch/x86/kernel/alternative.c:557 apply_returns (arch/x86/kernel/alternative.c:557 (discriminator 1))
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.19.0-rc4-00008-gee88d363d156 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014
  RIP: 0010:apply_returns (arch/x86/kernel/alternative.c:557 (discriminator 1))
  Code: ff ff 74 cb 48 83 c5 04 49 39 ee 0f 87 81 fe ff ff e9 22 ff ff ff 0f 0b 48 83 c5 04 49 39 ee 0f 87 6d fe ff ff e9 0e ff ff ff <0f> 0b 48 83 c5 04 49 39 ee 0f 87 59 fe ff ff e9 fa fe ff ff 48 89

The warning happened when apply_returns() failed to convert "JMP
__x86_return_thunk" to RET.  It was instead a JMP to nowhere, due to the
thunk relocation not getting resolved.

That rodata.o code is objcopy'd to .rodata, and later memcpy'd, so
relocations don't work (and are apparently silently ignored).

LKDTM is only used for testing, so the naked RET should be fine.  So
just disable return thunks for that file.

While at it, disable objtool and KCSAN for the file.

Fixes: 0b53c374b9 ("x86/retpoline: Use -mfunction-return")
Reported-by: kernel test robot <oliver.sang@intel.com>
Debugged-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/Ys58BxHxoDZ7rfpr@xsang-OptiPlex-9020/
2022-07-20 19:24:53 +02:00
Colin Ian King
5afbfa8cdd lkdtm: cfi: use NULL for a null pointer rather than zero
There is a pointer being initialized with a zero, use NULL instead.

Cleans up sparse warning:
drivers/misc/lkdtm/cfi.c💯27: warning: Using plain integer as NULL pointer

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220612202708.2754270-1-colin.i.king@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27 16:16:07 +02:00
Linus Torvalds
6f9b5ed8ca Char / Misc / Other smaller driver subsystem updates for 5.19-rc1
Here is the large set of char, misc, and other driver subsystem updates
 for 5.19-rc1.  The merge request for this has been delayed as I wanted
 to get lots of linux-next testing due to some late arrivals of changes
 for the habannalabs driver.
 
 Highlights of this merge are:
 	- habanalabs driver updates for new hardware types and fixes and
 	  other updates
 	- IIO driver tree merge which includes loads of new IIO drivers
 	  and cleanups and additions
 	- PHY driver tree merge with new drivers and small updates to
 	  existing ones
 	- interconnect driver tree merge with fixes and updates
 	- soundwire driver tree merge with some small fixes
 	- coresight driver tree merge with small fixes and updates
 	- mhi bus driver tree merge with lots of updates and new device
 	  support
 	- firmware driver updates
 	- fpga driver updates
 	- lkdtm driver updates (with a merge conflict, more on that
 	  below)
 	- extcon driver tree merge with small updates
 	- lots of other tiny driver updates and fixes and cleanups, full
 	  details in the shortlog.
 
 All of these have been in linux-next for almost 2 weeks with no reported
 problems.
 
 Note, there are 3 merge conflicts when merging this with your tree:
 	- MAINTAINERS, should be easy to resolve
 	- drivers/slimbus/qcom-ctrl.c, should be straightforward
 	  resolution
 	- drivers/misc/lkdtm/stackleak.c, not an easy resolution.  This
 	  has been noted in the linux-next tree for a while, and
 	  resolved there, here's a link to the resolution that Stephen
 	  came up with and that Kees says is correct:
 	  	https://lore.kernel.org/r/20220509185344.3fe1a354@canb.auug.org.au
 
 I will be glad to provide a merge point that contains these resolutions
 if that makes things any easier for you.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 
 iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCYpnkbA8cZ3JlZ0Brcm9h
 aC5jb20ACgkQMUfUDdst+ylOrgCggbbAFwESBY9o2YfpG+2VOLpc0GAAoJgY1XN8
 P/gumbLEpFvoBZ5xLIW8
 =KCgk
 -----END PGP SIGNATURE-----

Merge tag 'char-misc-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char / misc / other smaller driver subsystem updates from Greg KH:
 "Here is the large set of char, misc, and other driver subsystem
  updates for 5.19-rc1. The merge request for this has been delayed as I
  wanted to get lots of linux-next testing due to some late arrivals of
  changes for the habannalabs driver.

  Highlights of this merge are:

   - habanalabs driver updates for new hardware types and fixes and
     other updates

   - IIO driver tree merge which includes loads of new IIO drivers and
     cleanups and additions

   - PHY driver tree merge with new drivers and small updates to
     existing ones

   - interconnect driver tree merge with fixes and updates

   - soundwire driver tree merge with some small fixes

   - coresight driver tree merge with small fixes and updates

   - mhi bus driver tree merge with lots of updates and new device
     support

   - firmware driver updates

   - fpga driver updates

   - lkdtm driver updates (with a merge conflict, more on that below)

   - extcon driver tree merge with small updates

   - lots of other tiny driver updates and fixes and cleanups, full
     details in the shortlog.

  All of these have been in linux-next for almost 2 weeks with no
  reported problems"

* tag 'char-misc-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (387 commits)
  habanalabs: use separate structure info for each error collect data
  habanalabs: fix missing handle shift during mmap
  habanalabs: remove hdev from hl_ctx_get args
  habanalabs: do MMU prefetch as deferred work
  habanalabs: order memory manager messages
  habanalabs: return -EFAULT on copy_to_user error
  habanalabs: use NULL for eventfd
  habanalabs: update firmware header
  habanalabs: add support for notification via eventfd
  habanalabs: add topic to memory manager buffer
  habanalabs: handle race in driver fini
  habanalabs: add device memory scrub ability through debugfs
  habanalabs: use unified memory manager for CB flow
  habanalabs: unified memory manager new code for CB flow
  habanalabs/gaudi: set arbitration timeout to a high value
  habanalabs: add put by handle method to memory manager
  habanalabs: hide memory manager page shift
  habanalabs: Add separate poll interval value for protocol
  habanalabs: use get_task_pid() to take PID
  habanalabs: add prefetch flag to the MAP operation
  ...
2022-06-03 11:36:34 -07:00
Kees Cook
f260fd59e3 lkdtm/heap: Hide allocation size from -Warray-bounds
With the kmalloc() size annotations, GCC is smart enough to realize that
LKDTM is intentionally writing past the end of the buffer. This is on
purpose, of course, so hide the buffer from the optimizer. Silences:

../drivers/misc/lkdtm/heap.c: In function 'lkdtm_SLAB_LINEAR_OVERFLOW':
../drivers/misc/lkdtm/heap.c:59:13: warning: array subscript 256 is outside array bounds of 'void[1020]' [-Warray-bounds]
   59 |         data[1024 / sizeof(u32)] = 0x12345678;
      |         ~~~~^~~~~~~~~~~~~~~~~~~~
In file included from ../drivers/misc/lkdtm/heap.c:7:
In function 'kmalloc',
    inlined from 'lkdtm_SLAB_LINEAR_OVERFLOW' at ../drivers/misc/lkdtm/heap.c:54:14:
../include/linux/slab.h:581:24: note: at offset 1024 into object of size 1020 allocated by 'kmem_cache_alloc_trace'
  581 |                 return kmem_cache_alloc_trace(
      |                        ^~~~~~~~~~~~~~~~~~~~~~~
  582 |                                 kmalloc_caches[kmalloc_type(flags)][index],
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  583 |                                 flags, size);
      |                                 ~~~~~~~~~~~~

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-05-17 14:47:08 -07:00
Kees Cook
fc34eec686 lkdtm/usercopy: Check vmalloc and >0-order folios
Add coverage for the recently added usercopy checks for vmalloc and
folios, via USERCOPY_VMALLOC and USERCOPY_FOLIO respectively.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-05-17 14:35:49 -07:00
Kees Cook
d2b8060f16 lkdtm/usercopy: Rename "heap" to "slab"
To more clearly distinguish between the various heap types, rename the
slab tests to "slab".

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-05-11 22:46:09 -07:00
Mark Rutland
8c6a490e40 lkdtm/stackleak: fix CONFIG_GCC_PLUGIN_STACKLEAK=n
Recent rework broke building LKDTM when CONFIG_GCC_PLUGIN_STACKLEAK=n.
This patch fixes that breakage.

Prior to recent stackleak rework, the LKDTM STACKLEAK_ERASING code could
be built when the kernel was not built with stackleak support, and would
run a test that would almost certainly fail (or pass by sheer cosmic
coincidence), e.g.

| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: checking unused part of the thread stack (15560 bytes)...
| lkdtm: FAIL: the erased part is not found (checked 15560 bytes)
| lkdtm: FAIL: the thread stack is NOT properly erased!
| lkdtm: This is probably expected, since this kernel (5.18.0-rc2 aarch64) was built *without* CONFIG_GCC_PLUGIN_STACKLEAK=y

The recent rework to the test made it more accurate by using helpers
which are only defined when CONFIG_GCC_PLUGIN_STACKLEAK=y, and so when
building LKDTM when CONFIG_GCC_PLUGIN_STACKLEAK=n, we get a build
failure:

| drivers/misc/lkdtm/stackleak.c: In function 'check_stackleak_irqoff':
| drivers/misc/lkdtm/stackleak.c:30:46: error: implicit declaration of function 'stackleak_task_low_bound' [-Werror=implicit-function-declaration]
|    30 |         const unsigned long task_stack_low = stackleak_task_low_bound(current);
|       |                                              ^~~~~~~~~~~~~~~~~~~~~~~~
| drivers/misc/lkdtm/stackleak.c:31:47: error: implicit declaration of function 'stackleak_task_high_bound'; did you mean 'stackleak_task_init'? [-Werror=implicit-function-declaration]
|    31 |         const unsigned long task_stack_high = stackleak_task_high_bound(current);
|       |                                               ^~~~~~~~~~~~~~~~~~~~~~~~~
|       |                                               stackleak_task_init
| drivers/misc/lkdtm/stackleak.c:33:48: error: 'struct task_struct' has no member named 'lowest_stack'
|    33 |         const unsigned long lowest_sp = current->lowest_stack;
|       |                                                ^~
| drivers/misc/lkdtm/stackleak.c:74:23: error: implicit declaration of function 'stackleak_find_top_of_poison' [-Werror=implicit-function-declaration]
|    74 |         poison_high = stackleak_find_top_of_poison(task_stack_low, untracked_high);
|       |                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

This patch fixes the issue by not compiling the body of the test when
CONFIG_GCC_PLUGIN_STACKLEAK=n, and replacing this with an unconditional
XFAIL message. This means the pr_expected_config() in
check_stackleak_irqoff() is redundant, and so it is removed.

Where an architecture does not support stackleak, the test will log:

| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: XFAIL: stackleak is not supported on this arch (HAVE_ARCH_STACKLEAK=n)

Where an architectures does support stackleak, but this has not been
compiled in, the test will log:

| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: XFAIL: stackleak is not enabled (CONFIG_GCC_PLUGIN_STACKLEAK=n)

Where stackleak has been compiled in, the test behaves as usual:

| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: stackleak stack usage:
|   high offset: 336 bytes
|   current:     688 bytes
|   lowest:      1232 bytes
|   tracked:     1232 bytes
|   untracked:   672 bytes
|   poisoned:    14136 bytes
|   low offset:  8 bytes
| lkdtm: OK: the rest of the thread stack is properly erased

Fixes: f4cfacd92972cc44 ("lkdtm/stackleak: rework boundary management")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220506121145.1162908-1-mark.rutland@arm.com
2022-05-08 01:33:09 -07:00
Mark Rutland
f171d695f3 lkdtm/stackleak: check stack boundaries
The stackleak code relies upon the current SP and lowest recorded SP
falling within expected task stack boundaries.

Check this at the start of the test.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220427173128.2603085-12-mark.rutland@arm.com
2022-05-08 01:33:09 -07:00
Mark Rutland
f03a50938d lkdtm/stackleak: prevent unexpected stack usage
The lkdtm_STACKLEAK_ERASING() test is instrumentable and runs with IRQs
unmasked, so it's possible for unrelated code to clobber the task stack
and/or manipulate current->lowest_stack while the test is running,
resulting in spurious failures.

The regular stackleak erasing code is non-instrumentable and runs with
IRQs masked, preventing similar issues.

Make the body of the test non-instrumentable, and run it with IRQs
masked, avoiding such spurious failures.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220427173128.2603085-11-mark.rutland@arm.com
2022-05-08 01:33:08 -07:00
Mark Rutland
72b61896f2 lkdtm/stackleak: rework boundary management
There are a few problems with the way the LKDTM STACKLEAK_ERASING test
manipulates the stack pointer and boundary values:

* It uses the address of a local variable to determine the current stack
  pointer, rather than using current_stack_pointer directly. As the
  local variable could be placed anywhere within the stack frame, this
  can be an over-estimate of the true stack pointer value.

* Is uses an estimate of the current stack pointer as the upper boundary
  when scanning for poison, even though prior functions could have used
  more stack (and may have updated current->lowest stack accordingly).

* A pr_info() call is made in the middle of the test. As the printk()
  code is out-of-line and will make use of the stack, this could clobber
  poison and/or adjust current->lowest_stack. It would be better to log
  the metadata after the body of the test to avoid such problems.

These have been observed to result in spurious test failures on arm64.

In addition to this there are a couple of things which are sub-optimal:

* To avoid the STACK_END_MAGIC value, it conditionally modifies 'left'
  if this contains more than a single element, when it could instead
  calculate the bound unconditionally using stackleak_task_low_bound().

* It open-codes the poison scanning. It would be better if this used the
  same helper code as used by erasing function so that the two cannot
  diverge.

This patch reworks the test to avoid these issues, making use of the
recently introduced helpers to ensure this is aligned with the regular
stackleak code.

As the new code tests stack boundaries before accessing the stack, there
is no need to fail early when the tracked or untracked portions of the
stack extend all the way to the low stack boundary.

As stackleak_find_top_of_poison() is now used to find the top of the
poisoned region of the stack, the subsequent poison checking starts at
this boundary and verifies that stackleak_find_top_of_poison() is
working correctly.

The pr_info() which logged the untracked portion of stack is now moved
to the end of the function, and logs the size of all the portions of the
stack relevant to the test, including the portions at the top and bottom
of the stack which are not erased or scanned, and the current / lowest
recorded stack usage.

Tested on x86_64:

| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: stackleak stack usage:
|   high offset: 168 bytes
|   current:     336 bytes
|   lowest:      656 bytes
|   tracked:     656 bytes
|   untracked:   400 bytes
|   poisoned:    15152 bytes
|   low offset:  8 bytes
| lkdtm: OK: the rest of the thread stack is properly erased

Tested on arm64:

| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: stackleak stack usage:
|   high offset: 336 bytes
|   current:     656 bytes
|   lowest:      1232 bytes
|   tracked:     1232 bytes
|   untracked:   672 bytes
|   poisoned:    14136 bytes
|   low offset:  8 bytes
| lkdtm: OK: the rest of the thread stack is properly erased

Tested on arm64 with deliberate breakage to the starting stack value and
poison scanning:

| # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
| lkdtm: Performing direct entry STACKLEAK_ERASING
| lkdtm: FAIL: non-poison value 24 bytes below poison boundary: 0x0
| lkdtm: FAIL: non-poison value 32 bytes below poison boundary: 0xffff8000083dbc00
...
| lkdtm: FAIL: non-poison value 1912 bytes below poison boundary: 0x78b4b9999e8cb15
| lkdtm: FAIL: non-poison value 1920 bytes below poison boundary: 0xffff8000083db400
| lkdtm: stackleak stack usage:
|   high offset: 336 bytes
|   current:     688 bytes
|   lowest:      1232 bytes
|   tracked:     576 bytes
|   untracked:   288 bytes
|   poisoned:    15176 bytes
|   low offset:  8 bytes
| lkdtm: FAIL: the thread stack is NOT properly erased!
| lkdtm: Unexpected! This kernel (5.18.0-rc1-00013-g1f7b1f1e29e0-dirty aarch64) was built with CONFIG_GCC_PLUGIN_STACKLEAK=y

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220427173128.2603085-10-mark.rutland@arm.com
2022-05-08 01:33:08 -07:00
Mark Rutland
4130a61ceb lkdtm/stackleak: avoid spurious failure
The lkdtm_STACKLEAK_ERASING() test scans for a contiguous block of
poison values between the low stack bound and the stack pointer, and
fails if it does not find a sufficiently large block.

This can happen legitimately if the scan the low stack bound, which
could occur if functions called prior to lkdtm_STACKLEAK_ERASING() used
a large amount of stack. If this were to occur, it means that the erased
portion of the stack is smaller than the size used by the scan, but does
not cause a functional problem

In practice this is unlikely to happen, but as this is legitimate and
would not result in a functional problem, the test should not fail in
this case.

Remove the spurious failure case.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220427173128.2603085-9-mark.rutland@arm.com
2022-05-08 01:33:08 -07:00
Kees Cook
2a0338769f lkdtm: cfi: Fix type width for masking PAC bits
The masking for PAC bits wasn't handling 32-bit architectures correctly.
Replace the u64 cast with uintptr_t.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/lkml/CAMuHMdVz-J-1ZQ08u0bsQihDkcRmEPrtX5B_oRJ+Ns5jrasnUw@mail.gmail.com
Fixes: 2e53b877dc ("lkdtm: Add CFI_BACKWARD to test ROP mitigations")
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-04-26 17:11:05 -07:00
Kees Cook
2e53b877dc lkdtm: Add CFI_BACKWARD to test ROP mitigations
In order to test various backward-edge control flow integrity methods,
add a test that manipulates the return address on the stack. Currently
only arm64 Pointer Authentication and Shadow Call Stack is supported.

 $ echo CFI_BACKWARD | cat >/sys/kernel/debug/provoke-crash/DIRECT

Under SCS, successful test of the mitigation is reported as:

 lkdtm: Performing direct entry CFI_BACKWARD
 lkdtm: Attempting unchecked stack return address redirection ...
 lkdtm: ok: redirected stack return address.
 lkdtm: Attempting checked stack return address redirection ...
 lkdtm: ok: control flow unchanged.

Under PAC, successful test of the mitigation is reported by the PAC
exception handler:

 lkdtm: Performing direct entry CFI_BACKWARD
 lkdtm: Attempting unchecked stack return address redirection ...
 lkdtm: ok: redirected stack return address.
 lkdtm: Attempting checked stack return address redirection ...
 Unable to handle kernel paging request at virtual address bfffffc0088d0514
 Mem abort info:
   ESR = 0x86000004
   EC = 0x21: IABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x04: level 0 translation fault
 [bfffffc0088d0514] address between user and kernel address ranges
 ...

If the CONFIGs are missing (or the mitigation isn't working), failure
is reported as:

 lkdtm: Performing direct entry CFI_BACKWARD
 lkdtm: Attempting unchecked stack return address redirection ...
 lkdtm: ok: redirected stack return address.
 lkdtm: Attempting checked stack return address redirection ...
 lkdtm: FAIL: stack return address was redirected!
 lkdtm: This is probably expected, since this kernel was built *without* CONFIG_ARM64_PTR_AUTH_KERNEL=y nor CONFIG_SHADOW_CALL_STACK=y

Co-developed-by: Dan Li <ashimida@linux.alibaba.com>
Signed-off-by: Dan Li <ashimida@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/lkml/20220416001103.1524653-1-keescook@chromium.org
2022-04-16 13:57:23 -07:00
Kees Cook
73f62e60d8 lkdtm: Move crashtype definitions into each category
It's long been annoying that to add a new LKDTM test one had to update
lkdtm.h and core.c to get it "registered". Switch to a per-category
list and update the crashtype walking code in core.c to handle it.

This also means that all the lkdtm_* tests themselves can be static now.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-04-12 16:16:48 -07:00
Christophe Leroy
8bfdbddd68 lkdtm/bugs: Don't expect thread termination without CONFIG_UBSAN_TRAP
When you don't select CONFIG_UBSAN_TRAP, you get:

  # echo ARRAY_BOUNDS > /sys/kernel/debug/provoke-crash/DIRECT
[  102.265827] ================================================================================
[  102.278433] UBSAN: array-index-out-of-bounds in drivers/misc/lkdtm/bugs.c:342:16
[  102.287207] index 8 is out of range for type 'char [8]'
[  102.298722] ================================================================================
[  102.313712] lkdtm: FAIL: survived array bounds overflow!
[  102.318770] lkdtm: Unexpected! This kernel (5.16.0-rc1-s3k-dev-01884-g720dcf79314a ppc) was built with CONFIG_UBSAN_BOUNDS=y

It is not correct because when CONFIG_UBSAN_TRAP is not selected
you can't expect array bounds overflow to kill the thread.

Modify the logic so that when the kernel is built with
CONFIG_UBSAN_BOUNDS but without CONFIG_UBSAN_TRAP, you get a warning
about CONFIG_UBSAN_TRAP not been selected instead.

This also require a fix of pr_expected_config(), otherwise the
following error is encountered.

  CC      drivers/misc/lkdtm/bugs.o
drivers/misc/lkdtm/bugs.c: In function 'lkdtm_ARRAY_BOUNDS':
drivers/misc/lkdtm/bugs.c:351:2: error: 'else' without a previous 'if'
  351 |  else
      |  ^~~~

Fixes: c75be56e35 ("lkdtm/bugs: Add ARRAY_BOUNDS to selftests")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/363b58690e907c677252467a94fe49444c80ea76.1649704381.git.christophe.leroy@csgroup.eu
2022-04-12 16:16:48 -07:00
Kees Cook
f387e86d3a lkdtm/usercopy: Expand size of "out of frame" object
To be sufficiently out of range for the usercopy test to see the lifetime
mismatch, expand the size of the "bad" buffer, which will let it be
beyond current_stack_pointer regardless of stack growth direction.
Paired with the recent addition of stack depth checking under
CONFIG_HARDENED_USERCOPY=y, this will correctly start tripping again.

Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/lkml/762faf1b-0443-5ddf-4430-44a20cf2ec4d@collabora.com/
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-04-12 16:11:50 -07:00
Kees Cook
42db2594e4 lkdtm/heap: Note conditions for SLAB_LINEAR_OVERFLOW
It wasn't clear when SLAB_LINEAR_OVERFLOW would be expected to trip.
Explicitly describe it and include the CONFIGs in the kselftest.

Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-04-12 16:11:49 -07:00