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: <a2e01d7b-255d-bf64-f258-f3b7f211fc2a@redhat.com>
Date:   Mon, 22 Mar 2021 20:11:57 +0100
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Borislav Petkov <bp@...en8.de>
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, 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 22/03/21 19:56, Sean Christopherson wrote:
> EREMOVE can only fail if there's a kernel or hardware bug (or a VMM bug if
> running as a guest).  IME, nearly every kernel/KVM bug that I introduced that
> led to EREMOVE failure was also quite fatal to SGX, i.e. this is just the canary
> in the coal mine.

That was my recollection as well from previous threads but, to be fair 
to Boris, the commit message is a lot more scary (and, which is what 
triggers me, puts the blame on KVM).  It just says "KVM does not track 
how guest pages are used, which means that SGX virtualization use of 
EREMOVE might fail".

Paolo