linux-kernel - Re: [PATCH 0/3] hugetlbfs fallocate hole punch race with page faults

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: <20151019161840.63e6afaa73aceec23e351905@linux-foundation.org>
Date:	Mon, 19 Oct 2015 16:18:40 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Mike Kravetz <mike.kravetz@...cle.com>
Cc:	linux-mm@...ck.org, linux-kernel@...r.kernel.org,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Naoya Horiguchi <n-horiguchi@...jp.nec.com>,
	Hugh Dickins <hughd@...gle.com>,
	Davidlohr Bueso <dave@...olabs.net>
Subject: Re: [PATCH 0/3] hugetlbfs fallocate hole punch race with page
 faults

On Fri, 16 Oct 2015 15:08:27 -0700 Mike Kravetz <mike.kravetz@...cle.com> wrote:

> The hugetlbfs fallocate hole punch code can race with page faults.  The
> result is that after a hole punch operation, pages may remain within the
> hole.  No other side effects of this race were observed.
> 
> In preparation for adding userfaultfd support to hugetlbfs, it is desirable
> to plug or significantly shrink this hole.  This patch set uses the same
> mechanism employed in shmem (see commit f00cdc6df7).
> 

"still buggy but not as bad as before" isn't what we strive for ;) What
would it take to fix this for real?  An exhaustive description of the
bug would be a good starting point, thanks.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/