leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

ubsan: remove UBSAN_MISC in favor of individual options

Browse Source 
Make each UBSAN option individually selectable and remove UBSAN_MISC which
no longer has any purpose.  Add help text for each Kconfig, and include a
reference to the Clang sanitizer documentation.  Disable unsigned overflow
by default (not available with GCC and makes x86 unbootable with Clang).
Disable unreachable when objtool is in use (redundant and confuses things:
instrumentation appears at unreachable locations).

Link: https://lkml.kernel.org/r/20201203004437.389959-7-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kees Cook 2020-12-15 20:46:39 -08:00 committed by Linus Torvalds
parent d0a3ac549f
commit c637693b20
2 changed files with 57 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
Documentation/dev-tools/ubsan.rst
View File

@ -86,3 +86,4 @@ References
.. _1: https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
.. _2: https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
.. _3: https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html

82
lib/Kconfig.ubsan
View File

@ -84,48 +84,88 @@ config UBSAN_LOCAL_BOUNDS
where an added offset (which may not be known statically) is
out-of-bounds.
config UBSAN_MISC
bool "Enable all other Undefined Behavior sanity checks"
default UBSAN
help
This option enables all sanity checks that don't have their
own Kconfig options. Disable this if you only want to have
individually selected checks.
config UBSAN_SHIFT
def_bool UBSAN_MISC
bool "Perform checking for bit-shift overflows"
default UBSAN
depends on $(cc-option,-fsanitize=shift)
help
This option enables -fsanitize=shift which checks for bit-shift
operations that overflow to the left or go switch to negative
for signed types.
config UBSAN_DIV_ZERO
def_bool UBSAN_MISC
bool "Perform checking for integer divide-by-zero"
depends on $(cc-option,-fsanitize=integer-divide-by-zero)
help
This option enables -fsanitize=integer-divide-by-zero which checks
for integer division by zero. This is effectively redundant with the
kernel's existing exception handling, though it can provide greater
debugging information under CONFIG_UBSAN_REPORT_FULL.
config UBSAN_UNREACHABLE
def_bool UBSAN_MISC
bool "Perform checking for unreachable code"
# objtool already handles unreachable checking and gets angry about
# seeing UBSan instrumentation located in unreachable places.
depends on !STACK_VALIDATION
depends on $(cc-option,-fsanitize=unreachable)
help
This option enables -fsanitize=unreachable which checks for control
flow reaching an expected-to-be-unreachable position.
config UBSAN_SIGNED_OVERFLOW
def_bool UBSAN_MISC
bool "Perform checking for signed arithmetic overflow"
default UBSAN
depends on $(cc-option,-fsanitize=signed-integer-overflow)
help
This option enables -fsanitize=signed-integer-overflow which checks
for overflow of any arithmetic operations with signed integers.
config UBSAN_UNSIGNED_OVERFLOW
def_bool UBSAN_MISC
bool "Perform checking for unsigned arithmetic overflow"
depends on $(cc-option,-fsanitize=unsigned-integer-overflow)
help
This option enables -fsanitize=unsigned-integer-overflow which checks
for overflow of any arithmetic operations with unsigned integers. This
currently causes x86 to fail to boot.
config UBSAN_OBJECT_SIZE
def_bool UBSAN_MISC
bool "Perform checking for accesses beyond the end of objects"
default UBSAN
# gcc hugely expands stack usage with -fsanitize=object-size
# https://lore.kernel.org/lkml/CAHk-=wjPasyJrDuwDnpHJS2TuQfExwe=px-SzLeN8GFMAQJPmQ@mail.gmail.com/
depends on !CC_IS_GCC
depends on $(cc-option,-fsanitize=object-size)
help
This option enables -fsanitize=object-size which checks for accesses
beyond the end of objects where the optimizer can determine both the
object being operated on and its size, usually seen with bad downcasts,
or access to struct members from NULL pointers.
config UBSAN_BOOL
def_bool UBSAN_MISC
bool "Perform checking for non-boolean values used as boolean"
default UBSAN
depends on $(cc-option,-fsanitize=bool)
help
This option enables -fsanitize=bool which checks for boolean values being
loaded that are neither 0 nor 1.
config UBSAN_ENUM
def_bool UBSAN_MISC
bool "Perform checking for out of bounds enum values"
default UBSAN
depends on $(cc-option,-fsanitize=enum)
help
This option enables -fsanitize=enum which checks for values being loaded
into an enum that are outside the range of given values for the given enum.
config UBSAN_ALIGNMENT
bool "Perform checking for misaligned pointer usage"
default !HAVE_EFFICIENT_UNALIGNED_ACCESS
depends on !UBSAN_TRAP && !COMPILE_TEST
depends on $(cc-option,-fsanitize=alignment)
help
This option enables the check of unaligned memory accesses.
Enabling this option on architectures that support unaligned
accesses may produce a lot of false positives.
config UBSAN_SANITIZE_ALL
bool "Enable instrumentation for the entire kernel"
@ -138,16 +178,6 @@ config UBSAN_SANITIZE_ALL
Enabling this option will get kernel image size increased
significantly.
config UBSAN_ALIGNMENT
bool "Enable checks for pointers alignment"
default !HAVE_EFFICIENT_UNALIGNED_ACCESS
depends on !UBSAN_TRAP && !COMPILE_TEST
depends on $(cc-option,-fsanitize=alignment)
help
This option enables the check of unaligned memory accesses.
Enabling this option on architectures that support unaligned
accesses may produce a lot of false positives.
config TEST_UBSAN
tristate "Module for testing for undefined behavior detection"
depends on m