From: Sasha Levin <sasha.levin@oracle.com>
To: Hugh Dickins <hughd@google.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>,
Konstantin Khlebnikov <koct9i@gmail.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Mel Gorman <mgorman@suse.de>,
Andrey Ryabinin <a.ryabinin@samsung.com>
Subject: Re: mm: NULL ptr deref in migrate_page_move_mapping
Date: Fri, 26 Sep 2014 23:02:32 -0400 [thread overview]
Message-ID: <542628C8.8030004@oracle.com> (raw)
In-Reply-To: <alpine.LSU.2.11.1409221531570.1244@eggly.anvils>
On 09/22/2014 07:04 PM, Hugh Dickins wrote:
>> but I'm not sure what went wrong.
> Most likely would be a zeroing of the radix_tree node, just as you
> were experiencing zeroing of other mm structures in earlier weeks.
>
> Not that I've got any suggestions on where to take it from there.
I've added poisoning to a few mm related structures, and managed to
confirm that the issue here is indeed corruption rather than something
specific with the given structures.
Right now I'm looking into making KASan (Cc Andrey) to mark the poison
bytes somehow so it would trigger an error on access, that way we'll
know what's corruption them.
Andrey, since it takes a while to trigger this corruption, could you
confirm that if I kasan_poison_shadow() a few bytes I will get a KASan
report on any read/write to them?
Thanks,
Sasha
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next prev parent reply other threads:[~2014-09-27 3:04 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-22 15:30 mm: NULL ptr deref in migrate_page_move_mapping Sasha Levin
2014-09-22 23:04 ` Hugh Dickins
2014-09-22 23:49 ` Sasha Levin
2014-09-27 3:02 ` Sasha Levin [this message]
2014-09-27 7:01 ` Andrey Ryabinin
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