linux-kernel - Re: [PATCH v3 03/25] x86/sgx: Wipe out EREMOVE from sgx_free_epc

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]

Message-ID: <20210323160604.GB4729@zn.tnic>
Date:   Tue, 23 Mar 2021 17:06:04 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Sean Christopherson <seanjc@...gle.com>
Cc:     Kai Huang <kai.huang@...el.com>, kvm@...r.kernel.org,
        x86@...nel.org, linux-sgx@...r.kernel.org,
        linux-kernel@...r.kernel.org, jarkko@...nel.org, luto@...nel.org,
        dave.hansen@...el.com, rick.p.edgecombe@...el.com,
        haitao.huang@...el.com, pbonzini@...hat.com, tglx@...utronix.de,
        mingo@...hat.com, hpa@...or.com
Subject: Re: [PATCH v3 03/25] x86/sgx: Wipe out EREMOVE from
 sgx_free_epc_page()

On Tue, Mar 23, 2021 at 03:45:14PM +0000, Sean Christopherson wrote:
> Practically speaking, "basic" deployments of SGX VMs will be insulated from
> this bug.  KVM doesn't support EPC oversubscription, so even if all EPC is
> exhausted, new VMs will fail to launch, but existing VMs will continue to chug
> along with no ill effects....

Ok, so it sounds to me like *at* *least* there should be some writeup in
Documentation/ explaining to the user what to do when she sees such an
EREMOVE failure, perhaps the gist of this thread and then possibly the
error message should point to that doc.

We will of course have to revisit when this hits the wild and people
start (or not) hitting this. But judging by past experience, if it is
there, we will hit it. Murphy says so.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette