hardening fixes for v6.9-rc5

- Correctly disable UBSAN configs in configs/hardening (Nathan Chancellor)

- Add missing signed integer overflow trap types to arm64 handler
ubsan: Add awareness of signed integer overflow traps

On arm64, UBSAN traps can be decoded from the trap instruction. Add the
add, sub, and mul overflow trap codes now that CONFIG_UBSAN_SIGNED_WRAP
exists. Seen under clang 19:

  Internal error: UBSAN: unrecognized failure code: 00000000f2005515 [#1] PREEMPT SMP

Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/lkml/20240411-fix-ubsan-in-hardening-config-v1-0-e0177c80ffaa@kernel.org
Fixes: 557f8c582a9b ("ubsan: Reintroduce signed overflow sanitizer")
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240415182832.work.932-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
1 file changed