linux-kernel - Re: Intermittent memory corruption with v4.13-rc6+ and earlier

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Date:   Thu, 24 Aug 2017 13:36:48 +0100
From:   Mark Rutland <mark.rutland@....com>
To:     Michal Hocko <mhocko@...nel.org>
Cc:     linux-kernel@...r.kernel.org, syzkaller@...glegroups.com,
        linux-mm@...ck.org, linux-fsdevel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Jan Kara <jack@...e.cz>, Ingo Molnar <mingo@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Vlastimil Babka <vbabka@...e.cz>, will.deacon@....com
Subject: Re: Intermittent memory corruption with v4.13-rc6+ and earlier

On Thu, Aug 24, 2017 at 01:48:34PM +0200, Michal Hocko wrote:
> On Thu 24-08-17 12:37:43, Mark Rutland wrote:
> > Hi,
> > 
> > I'm chasing intermittent memory corruption bugs seen at least on rc5,
> > rc6, and yesterday's HEAD (98b9f8a4549909c6), on arm64. 
> > 
> > It looks like we make use of dangling references to a freed struct file,
> > which is caught by KASAN. Without KASAN, I see a number of other
> > intermittent issues that I suspect are the result of this memory
> > corruption. I've included an example splat below, complete with KASAN's
> > alloc/free traces at the end of this mail.
> 
> Is it possible this is the same issue as the one fixed by
> http://lkml.kernel.org/r/20170823211408.31198-1-ebiggers3@gmail.com?

That sounds plausible, and so far the fix seems to help. Thanks for the
pointer!

I'll leave that running for a while, just in case.

Thanks,
Mark.