linux-kernel - Re: [PATCH -next v3 2/2] powerpc: add support for syscall stack randomization

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:   Wed, 27 Jul 2022 13:32:09 -0700
From:   Kees Cook <keescook@...omium.org>
To:     Xiu Jianfeng <xiujianfeng@...wei.com>
Cc:     mpe@...erman.id.au, benh@...nel.crashing.org, paulus@...ba.org,
        npiggin@...il.com, christophe.leroy@...roup.eu, tglx@...utronix.de,
        mark.rutland@....com, linuxppc-dev@...ts.ozlabs.org,
        linux-kernel@...r.kernel.org, linux-hardening@...r.kernel.org
Subject: Re: [PATCH -next v3 2/2] powerpc: add support for syscall stack
 randomization

On Fri, Jul 01, 2022 at 04:24:35PM +0800, Xiu Jianfeng wrote:
> Add support for adding a random offset to the stack while handling
> syscalls. This patch uses mftb() instead of get_random_int() for better
> performance.
> 
> In order to avoid unconditional stack canaries on syscall entry (due to
> the use of alloca()), also disable stack protector to avoid triggering
> needless checks and slowing down the entry path. As there is no general
> way to control stack protector coverage with a function attribute, this
> must be disabled at the compilation unit level.
> 
> Signed-off-by: Xiu Jianfeng <xiujianfeng@...wei.com>

Reviewed-by: Kees Cook <keescook@...omium.org>

-Kees

-- 
Kees Cook