From f4626c12e4b538f757a73d08f4d86d564175b4f7 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 15 Apr 2024 11:28:35 -0700 Subject: [PATCH] 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 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 Link: https://lore.kernel.org/r/20240415182832.work.932-kees@kernel.org Signed-off-by: Kees Cook --- lib/ubsan.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/lib/ubsan.c b/lib/ubsan.c index 5fc107f61934..a1c983d148f1 100644 --- a/lib/ubsan.c +++ b/lib/ubsan.c @@ -44,9 +44,10 @@ const char *report_ubsan_failure(struct pt_regs *regs, u32 check_type) case ubsan_shift_out_of_bounds: return "UBSAN: shift out of bounds"; #endif -#ifdef CONFIG_UBSAN_DIV_ZERO +#if defined(CONFIG_UBSAN_DIV_ZERO) || defined(CONFIG_UBSAN_SIGNED_WRAP) /* - * SanitizerKind::IntegerDivideByZero emits + * SanitizerKind::IntegerDivideByZero and + * SanitizerKind::SignedIntegerOverflow emit * SanitizerHandler::DivremOverflow. */ case ubsan_divrem_overflow: @@ -77,6 +78,19 @@ const char *report_ubsan_failure(struct pt_regs *regs, u32 check_type) return "UBSAN: alignment assumption"; case ubsan_type_mismatch: return "UBSAN: type mismatch"; +#endif +#ifdef CONFIG_UBSAN_SIGNED_WRAP + /* + * SanitizerKind::SignedIntegerOverflow emits + * SanitizerHandler::AddOverflow, SanitizerHandler::SubOverflow, + * or SanitizerHandler::MulOverflow. + */ + case ubsan_add_overflow: + return "UBSAN: integer addition overflow"; + case ubsan_sub_overflow: + return "UBSAN: integer subtraction overflow"; + case ubsan_mul_overflow: + return "UBSAN: integer multiplication overflow"; #endif default: return "UBSAN: unrecognized failure code";