linux-kernel - Re: [PATCH 14/18] ipv4: prevent bounds-check bypass via speculative execution

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: <20180106151424.GA17924@kroah.com>
Date:   Sat, 6 Jan 2018 16:14:24 +0100
From:   Greg KH <gregkh@...uxfoundation.org>
To:     Alan Cox <gnomes@...rguk.ukuu.org.uk>
Cc:     Dan Williams <dan.j.williams@...el.com>,
        linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
        Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>,
        netdev@...r.kernel.org, peterz@...radead.org,
        Alexey Kuznetsov <kuznet@....inr.ac.ru>, tglx@...utronix.de,
        torvalds@...ux-foundation.org,
        "David S. Miller" <davem@...emloft.net>,
        Elena Reshetova <elena.reshetova@...el.com>,
        alan@...ux.intel.com
Subject: Re: [PATCH 14/18] ipv4: prevent bounds-check bypass via speculative
 execution

On Sat, Jan 06, 2018 at 12:23:47PM +0000, Alan Cox wrote:
> On Sat, 6 Jan 2018 10:01:54 +0100
> Greg KH <gregkh@...uxfoundation.org> wrote:
> 
> > On Fri, Jan 05, 2018 at 05:11:10PM -0800, Dan Williams wrote:
> > > Static analysis reports that 'offset' may be a user controlled value  
> > 
> > Can I see the rule that determined that?  It does not feel like that is
> > correct, given the 3+ levels deep that this function gets this value
> > from...
> 
> On a current x86 you can execute something upwards of 150 instructions in
> a speculation window.

Yeah, I agree, it's deep :(

But for this patch, I thought the prior review determined that it was
not a problem.  Was that somehow proven incorrect?

thanks,

greg k-h