In preparation for adding Clang sanitizer coverage stack depth tracking
that can support stack depth callbacks:
- Add the new top-level CONFIG_KSTACK_ERASE option which will be
implemented either with the stackleak GCC plugin, or with the Clang
stack depth callback support.
- Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE,
but keep it for anything specific to the GCC plugin itself.
- Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named
for what it does rather than what it protects against), but leave as
many of the internals alone as possible to avoid even more churn.
While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS,
since that's the only place it is referenced from.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
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 2d47c6956a ("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>
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: c75be56e35 ("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>
CONFIG_HARDENED_USERCOPY_FALLBACK config option has been removed in
commit 53944f171a ("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>
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>
