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Date: Fri, 27 Mar 2015 08:30:20 +0100
From: Quentin Casasnovas <quentin.casasnovas@oracle.com>
To: "Yu, Fenghua" <fenghua.yu@intel.com>
Cc: "Hansen, Dave" <dave.hansen@intel.com>, Oleg Nesterov <oleg@redhat.com>,
        Borislav Petkov <bp@suse.de>,
        Quentin Casasnovas <quentin.casasnovas@oracle.com>,
        Andy Lutomirski <luto@amacapital.net>, Ingo Molnar <mingo@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
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        Suresh Siddha <sbsiddha@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: Oops with tip/x86/fpu
Message-ID: <20150327073020.GB6295@chrystal.uk.oracle.com>
References: <54F74F59.5070107@intel.com>
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 <20150305182203.GA4203@redhat.com>
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On Thu, Mar 26, 2015 at 10:48:18PM +0000, Yu, Fenghua wrote:
> > > sctxt->fpstate=(void *)1 changes the fpstate pointer in the
> > > sigcontext. It will generate segfault and bad frame info in kernel.
> > >
> > > This is expected behavior, right? Is this still a valid test?
> > 
> > Just to be clear, I saw a full-on kernel panic induced from an unprivileged
> > application.
> > 
> > Are you seeing something different?
> 
> I use latest tip tree. Maybe it has the fixes already. I see "bad frame"
> reported in kernel. Seems the issue has been fixed in tip tree.
> 

Fenghua, if you're interested, the details are now public here:

 http://seclists.org/oss-sec/2015/q1/877

Quentin