linux-kernel - Re: [PATCH v3 21/36] arm64/mm: Implement map_shadow

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:   Fri, 4 Aug 2023 14:38:10 +0100
From:   Mark Brown <broonie@...nel.org>
To:     "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
Cc:     "corbet@....net" <corbet@....net>,
        "ardb@...nel.org" <ardb@...nel.org>,
        "keescook@...omium.org" <keescook@...omium.org>,
        "Szabolcs.Nagy@....com" <Szabolcs.Nagy@....com>,
        "shuah@...nel.org" <shuah@...nel.org>,
        "maz@...nel.org" <maz@...nel.org>,
        "james.morse@....com" <james.morse@....com>,
        "debug@...osinc.com" <debug@...osinc.com>,
        "aou@...s.berkeley.edu" <aou@...s.berkeley.edu>,
        "akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
        "catalin.marinas@....com" <catalin.marinas@....com>,
        "hjl.tools@...il.com" <hjl.tools@...il.com>,
        "paul.walmsley@...ive.com" <paul.walmsley@...ive.com>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "palmer@...belt.com" <palmer@...belt.com>,
        "oleg@...hat.com" <oleg@...hat.com>,
        "arnd@...db.de" <arnd@...db.de>,
        "ebiederm@...ssion.com" <ebiederm@...ssion.com>,
        "will@...nel.org" <will@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "suzuki.poulose@....com" <suzuki.poulose@....com>,
        "kvmarm@...ts.linux.dev" <kvmarm@...ts.linux.dev>,
        "linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
        "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kselftest@...r.kernel.org" <linux-kselftest@...r.kernel.org>,
        "linux-arch@...r.kernel.org" <linux-arch@...r.kernel.org>,
        "oliver.upton@...ux.dev" <oliver.upton@...ux.dev>,
        "linux-riscv@...ts.infradead.org" <linux-riscv@...ts.infradead.org>
Subject: Re: [PATCH v3 21/36] arm64/mm: Implement map_shadow_stack()

On Wed, Aug 02, 2023 at 05:27:54PM +0100, Mark Brown wrote:
> On Tue, Aug 01, 2023 at 08:57:59PM +0000, Edgecombe, Rick P wrote:

> > To make sure we are on the same page: What I'm saying is say we do
> > something like add another flag SHADOW_STACK_SET_MARKER that means add
> > a marker at the end (making the token off by one frame). Then you can
> > just reject any flags != (SHADOW_STACK_SET_MARKER |
> > SHADOW_STACK_SET_TOKEN) value, and leave the rest of the code as is. So
> > not really implementing anything new. 

> > Then x86 could use the same flag meanings if/when it implements end
> > markers. If it doesn't seem worth it, it's not a big deal on my end.
> > Just seemed that they were needlessly diverging.

> Yes, my understanding of the flags is the same.  I'll definitely
> implement omitting the cap since there's an actual use case for that
> (extending an existing stack, it's marginally safer to not have any
> opportunity to pivot into the newly allocated region).

BTW are you planning to repost the series for this release?  We're
almost at -rc5 which is pretty late and I didn't see anything yet.  It
looks like there's a branch in tip that's getting some updates but it's
not getting merged for -next.

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)