linux-kernel - Re: [PATCH 03/10] kvmclock: Use free_decrypted

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: <11b91e72cb4dff760e387133a970956280ca9e00.camel@intel.com>
Date:   Wed, 18 Oct 2023 15:57:32 +0000
From:   "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
To:     "Lutomirski, Andy" <luto@...nel.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
        "thomas.lendacky@....com" <thomas.lendacky@....com>,
        "Reshetova, Elena" <elena.reshetova@...el.com>,
        "kirill.shutemov@...ux.intel.com" <kirill.shutemov@...ux.intel.com>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "Christopherson,, Sean" <seanjc@...gle.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "Cui, Dexuan" <decui@...rosoft.com>,
        "Yamahata, Isaku" <isaku.yamahata@...el.com>,
        "mikelley@...rosoft.com" <mikelley@...rosoft.com>,
        "hpa@...or.com" <hpa@...or.com>,
        "peterz@...radead.org" <peterz@...radead.org>,
        "bp@...en8.de" <bp@...en8.de>,
        "linux-s390@...r.kernel.org" <linux-s390@...r.kernel.org>,
        "sathyanarayanan.kuppuswamy@...ux.intel.com" 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        "x86@...nel.org" <x86@...nel.org>
CC:     "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "pbonzini@...hat.com" <pbonzini@...hat.com>,
        "wanpengli@...cent.com" <wanpengli@...cent.com>,
        "vkuznets@...hat.com" <vkuznets@...hat.com>
Subject: Re: [PATCH 03/10] kvmclock: Use free_decrypted_pages()

On Tue, 2023-10-17 at 22:20 -0700, Kuppuswamy Sathyanarayanan wrote:
> 
> 
> On 10/17/2023 1:24 PM, Rick Edgecombe wrote:
> > On TDX it is possible for the untrusted host to cause
> > set_memory_encrypted() or set_memory_decrypted() to fail such that
> > an
> > error is returned and the resulting memory is shared. Callers need
> > to take
> > care to handle these errors to avoid returning decrypted (shared)
> > memory to
> > the page allocator, which could lead to functional or security
> > issues.
> > 
> > Kvmclock could free decrypted/shared pages if
> > set_memory_decrypted() fails.
> > Use the recently added free_decrypted_pages() to avoid this.
> > 
> > Cc: Paolo Bonzini <pbonzini@...hat.com>
> > Cc: Wanpeng Li <wanpengli@...cent.com>
> > Cc: Vitaly Kuznetsov <vkuznets@...hat.com>
> > Cc: kvm@...r.kernel.org
> > Signed-off-by: Rick Edgecombe <rick.p.edgecombe@...el.com>
> > ---
> 
> Since it a fix, do you want to add Fixes tag?
> 
> Otherwise, it looks good to me.
> 
> Reviewed-by: Kuppuswamy Sathyanarayanan
> <sathyanarayanan.kuppuswamy@...ux.intel.com>

Thanks. Yes, the thinking was to mark all these for stable, but some
patches are still RFC for this version. I'll add it for all non-RFC
ones in the next version.