linux-kernel - Re: [PATCH] hugetlb: ensure we do not reference a surplus page after handing it to buddy

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]

Date:	Tue, 19 Feb 2008 12:41:51 -0600
From:	Adam Litke <agl@...ibm.com>
To:	Andy Whitcroft <apw@...dowen.org>
Cc:	Andrew Morton <akpm@...l.org>,
	Nishanth Aravamudan <nacc@...ibm.com>,
	William Irwin <wli@...omorphy.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] hugetlb: ensure we do not reference a surplus page
	after handing it to buddy

Indeed.  I'll take credit for this thinko...

On Tue, 2008-02-19 at 18:28 +0000, Andy Whitcroft wrote:
> When we free a page via free_huge_page and we detect that we are in
> surplus the page will be returned to the buddy.  After this we no longer
> own the page.  However at the end free_huge_page we clear out our mapping
> pointer from page private.  Even where the page is not a surplus we
> free the page to the hugepage pool, drop the pool locks and then clear
> page private.  In either case the page may have been reallocated.  BAD.
> 
> Make sure we clear out page private before we free the page.
> 
> Signed-off-by: Andy Whitcroft <apw@...dowen.org>

Acked-by: Adam Litke <agl@...ibm.com>

-- 
Adam Litke - (agl at us.ibm.com)
IBM Linux Technology Center

--
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/