linux-kernel - Re: [PATCH 4.14 05/40] efi/libstub: Disable Shadow Call Stack

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 26 Sep 2022 13:14:08 +0200
From:   Pavel Machek <pavel@...x.de>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     linux-kernel@...r.kernel.org, stable@...r.kernel.org,
        James Morse <james.morse@....com>,
        Sami Tolvanen <samitolvanen@...gle.com>,
        Kees Cook <keescook@...omium.org>,
        Ard Biesheuvel <ardb@...nel.org>,
        Will Deacon <will@...nel.org>, Sasha Levin <sashal@...nel.org>
Subject: Re: [PATCH 4.14 05/40] efi/libstub: Disable Shadow Call Stack

Hi!

> From: Sami Tolvanen <samitolvanen@...gle.com>
> 
> [ Upstream commit cc49c71d2abe99c1c2c9bedf0693ad2d3ee4a067 ]
> 
> Shadow stacks are not available in the EFI stub, filter out SCS
> flags.

AFAICT, SCS is not available in 4.19, CC_FLAGS_SCS is not defined
there, and we should apply this patch.

Best regards,
								Pavel

> +++ b/drivers/firmware/efi/libstub/Makefile
> @@ -23,6 +23,9 @@ KBUILD_CFLAGS			:= $(cflags-y) -DDISABLE_BRANCH_PROFILING \
>  				   $(call cc-option,-ffreestanding) \
>  				   $(call cc-option,-fno-stack-protector)
>  
> +# remove SCS flags from all objects in this directory
> +KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))
> +
>  GCOV_PROFILE			:= n
>  KASAN_SANITIZE			:= n
>  UBSAN_SANITIZE			:= n

-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

Download attachment "signature.asc" of type "application/pgp-signature" (182 bytes)