selftests/lkdtm: Disable CONFIG_UBSAN_TRAP in test config

The lkdtm selftest config fragment enables CONFIG_UBSAN_TRAP to make the
ARRAY_BOUNDS test kill the calling process when an out-of-bound access
is detected by UBSAN. However, after this [1] commit, UBSAN is triggered
under many new scenarios that weren't detected before, such as in struct
definitions with fixed-size trailing arrays used as flexible arrays. As
a result, CONFIG_UBSAN_TRAP=y has become a very aggressive option to
enable except for specific situations.

`make kselftest-merge` applies CONFIG_UBSAN_TRAP=y to the kernel config
for all selftests, which makes many of them fail because of system hangs
during boot.

This change removes the config option from the lkdtm kselftest and
configures the ARRAY_BOUNDS test to look for UBSAN reports rather than
relying on the calling process being killed.

[1] commit 2d47c6956ab3 ("ubsan: Tighten UBSAN_BOUNDS on GCC")'

Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230802063252.1917997-1-ricardo.canuelo@collabora.com
Signed-off-by: Kees Cook <keescook@chromium.org>

selftests/lkdtm: Add configs for stackleak and "after free" tests

Add config options which are needed for LKDTM sub-tests:
STACKLEAK_ERASING test needs GCC_PLUGIN_STACKLEAK config.
READ_AFTER_FREE and READ_BUDDY_AFTER_FREE tests need
INIT_ON_FREE_DEFAULT_ON config.

Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220517132932.1484719-1-usama.anjum@collabora.com

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>

selftests/lkdtm: Add UBSAN config

UBSAN_BOUNDS and UBSAN_TRAP depend on UBSAN config option.
merge_config.sh script generates following warnings if parent config
doesn't have UBSAN config already enabled and UBSAN_BOUNDS/UBSAN_TRAP
config options don't get added to the parent config.

Value requested for CONFIG_UBSAN_BOUNDS not in final .config
Requested value: CONFIG_UBSAN_BOUNDS=y
Actual value:

Value requested for CONFIG_UBSAN_TRAP not in final .config
Requested value: CONFIG_UBSAN_TRAP=y
Actual value:

Fix this by including UBSAN config.

Fixes: c75be56e35b2 ("lkdtm/bugs: Add ARRAY_BOUNDS to selftests")
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/20220121145154.1795447-2-usama.anjum@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

selftests/lkdtm: Remove dead config option

CONFIG_HARDENED_USERCOPY_FALLBACK config option has been removed in
commit 53944f171a89 ("mm: remove HARDENED_USERCOPY_FALLBACK"). Remove it
from the lkdtm selftest config.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/20220121145154.1795447-1-usama.anjum@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

selftests/lkdtm: Add UBSAN config

UBSAN_BOUNDS and UBSAN_TRAP depend on UBSAN config option.
merge_config.sh script generates following warnings if parent config
doesn't have UBSAN config already enabled and UBSAN_BOUNDS/UBSAN_TRAP
config options don't get added to the parent config.

Value requested for CONFIG_UBSAN_BOUNDS not in final .config
Requested value: CONFIG_UBSAN_BOUNDS=y
Actual value:

Value requested for CONFIG_UBSAN_TRAP not in final .config
Requested value: CONFIG_UBSAN_TRAP=y
Actual value:

Fix this by including UBSAN config.

Fixes: c75be56e35b2 ("lkdtm/bugs: Add ARRAY_BOUNDS to selftests")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/lkdtm: Remove dead config option

CONFIG_HARDENED_USERCOPY_FALLBACK config option has been removed in
commit 53944f171a89 ("mm: remove HARDENED_USERCOPY_FALLBACK"). Remove it
from the lkdtm selftest config.

Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lkdtm/bugs: Check that a per-task stack canary exists

Introduce REPORT_STACK_CANARY to check for differing stack canaries
between two processes (i.e. that an architecture is correctly implementing
per-task stack canaries), using the task_struct canary as the hint to
locate in the stack. Requires that one of the processes being tested
not be pid 1.

Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211022223826.330653-3-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

lkdtm/bugs: Add ARRAY_BOUNDS to selftests

Add CONFIG hints about why the ARRAY_BOUNDS test might fail, and
similarly include the CONFIGs needed to pass the ARRAY_BOUNDS test via
the selftests, and add to selftests.

Cc: kernelci@groups.io
Suggested-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210818174855.2307828-2-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

lkdtm/heap: Add init_on_alloc tests

Add SLAB and page allocator tests for init_on_alloc. Testing for
init_on_free was already happening via the poisoning tests.

Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210623203936.3151093-10-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

selftests/lkdtm: Enable various testable CONFIGs

Add a handful of LKDTM-testable features that depend on certain CONFIGs
so that they are visible in logs for CI systems that run the selftests.
Others could be added, but may be seen as having too high a trade-off
for general testing.

Cc: kernelci@groups.io
Suggested-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210623203936.3151093-9-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

selftests/lkdtm: Add tests for LKDTM targets

This adds a basic framework for running all the "safe" LKDTM tests. This
will allow easy introspection into any selftest logs to examine the
results of most LKDTM tests.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>