From: Kees Cook Date: Fri, 7 Mar 2025 04:19:10 +0000 (-0800) Subject: ubsan/overflow: Enable pattern exclusions X-Git-Tag: v6.15-rc1~233^2~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=272a767063a6856cd1e18bb951d2be4f047b9858;p=thirdparty%2Fkernel%2Flinux.git ubsan/overflow: Enable pattern exclusions To make integer wrap-around mitigation actually useful, the associated sanitizers must not instrument cases where the wrap-around is explicitly defined (e.g. "-2UL"), being tested for (e.g. "if (a + b < a)"), or where it has no impact on code flow (e.g. "while (var--)"). Enable pattern exclusions for the integer wrap sanitizers. Reviewed-by: Justin Stitt Link: https://lore.kernel.org/r/20250307041914.937329-2-kees@kernel.org Signed-off-by: Kees Cook --- diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index 63e5622010e0f..888c2e72c586e 100644 --- a/lib/Kconfig.ubsan +++ b/lib/Kconfig.ubsan @@ -120,6 +120,7 @@ config UBSAN_INTEGER_WRAP bool "Perform checking for integer arithmetic wrap-around" default UBSAN depends on !COMPILE_TEST + depends on $(cc-option,-fsanitize-undefined-ignore-overflow-pattern=all) depends on $(cc-option,-fsanitize=signed-integer-overflow) depends on $(cc-option,-fsanitize=unsigned-integer-overflow) depends on $(cc-option,-fsanitize=implicit-signed-integer-truncation) diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan index 4fad9afed24cf..233379c193a75 100644 --- a/scripts/Makefile.ubsan +++ b/scripts/Makefile.ubsan @@ -15,6 +15,7 @@ ubsan-cflags-$(CONFIG_UBSAN_TRAP) += $(call cc-option,-fsanitize-trap=undefined export CFLAGS_UBSAN := $(ubsan-cflags-y) ubsan-integer-wrap-cflags-$(CONFIG_UBSAN_INTEGER_WRAP) += \ + -fsanitize-undefined-ignore-overflow-pattern=all \ -fsanitize=signed-integer-overflow \ -fsanitize=unsigned-integer-overflow \ -fsanitize=implicit-signed-integer-truncation \