linux-kernel - Re: [PATCH] ubifs: Get/put page when changing PG

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: <1605618.KFvAoLHJ4l@blindfold>
Date:   Mon, 17 Dec 2018 12:32:04 +0100
From:   Richard Weinberger <richard@....at>
To:     "Kirill A. Shutemov" <kirill@...temov.name>
Cc:     linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-fsdevel@...r.kernel.org, hsiangkao@...l.ru,
        kirill.shutemov@...ux.intel.com, stable@...r.kernel.org,
        zhangjun <openzhangj@...il.com>
Subject: Re: [PATCH] ubifs: Get/put page when changing PG_private

Am Montag, 17. Dezember 2018, 11:59:44 CET schrieb Kirill A. Shutemov:
> On Sat, Dec 15, 2018 at 04:01:30PM +0100, Richard Weinberger wrote:
> > The page migration code assumes that a page with PG_private
> > set has its page count elevated by 1.
> > UBIFS never did this and therefore the migration code was unable
> > to migrate some pages owned by UBIFS.
> > The lead to situations where the CMA memory allocator failed to
> > allocate memory.
> > 
> > Fix this by using get/put_page when changing PG_private.
> 
> Looks good to me.
> 
> Acked-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
> 
> > Cc: <stable@...r.kernel.org>
> > Cc: zhangjun <openzhangj@...il.com>
> > Fixes: 4ac1c17b2044 ("UBIFS: Implement ->migratepage()")
> 
> It is fair to reference the commit here. But I believe the bug itself
> predates the commit and relevant not only for migration.

My intention was not blaming you. :)
IMHO backporting the fix makes only sense up to that commit.
 
> We might make it clear in the commit message.

Fair point, I'll rephrase.

Thanks,
//richard