linux-kernel - Re: [PATCH v3 3/3] list_debug: Introduce CONFIG_DEBUG_LIST

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:   Tue, 8 Aug 2023 14:27:14 -0700
From:   Kees Cook <keescook@...omium.org>
To:     Marco Elver <elver@...gle.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Guenter Roeck <linux@...ck-us.net>,
        Peter Zijlstra <peterz@...radead.org>,
        Mark Rutland <mark.rutland@....com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Marc Zyngier <maz@...nel.org>,
        Oliver Upton <oliver.upton@...ux.dev>,
        James Morse <james.morse@....com>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Zenghui Yu <yuzenghui@...wei.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Nathan Chancellor <nathan@...nel.org>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Tom Rix <trix@...hat.com>, Miguel Ojeda <ojeda@...nel.org>,
        Sami Tolvanen <samitolvanen@...gle.com>,
        linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev,
        linux-kernel@...r.kernel.org, llvm@...ts.linux.dev,
        Dmitry Vyukov <dvyukov@...gle.com>,
        Alexander Potapenko <glider@...gle.com>,
        kasan-dev@...glegroups.com, linux-toolchains@...r.kernel.org
Subject: Re: [PATCH v3 3/3] list_debug: Introduce CONFIG_DEBUG_LIST_MINIMAL

On Tue, Aug 08, 2023 at 12:17:27PM +0200, Marco Elver wrote:
> Numerous production kernel configs (see [1, 2]) are choosing to enable
> CONFIG_DEBUG_LIST, which is also being recommended by KSPP for hardened
> configs [3]. The feature has never been designed with performance in
> mind, yet common list manipulation is happening across hot paths all
> over the kernel.
> 
> Introduce CONFIG_DEBUG_LIST_MINIMAL, which performs list pointer
> checking inline, and only upon list corruption delegates to the
> reporting slow path.

I'd really like to get away from calling this "DEBUG", since it's used
more for hardening (CONFIG_LIST_HARDENED?). Will Deacon spent some time
making this better a while back, but the series never landed. Do you
have a bit of time to look through it?

https://github.com/KSPP/linux/issues/10
https://lore.kernel.org/lkml/20200324153643.15527-1-will@kernel.org/

-Kees

-- 
Kees Cook