linux-kernel - Re: [PATCH V1] lib/scatterlist: Fix to calculate the last

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: <0e0c8aaf-9ec6-d3e0-b530-1a4ec405d0f2@nvidia.com>
Date:   Wed, 11 Jan 2023 10:22:24 +0000
From:   Chaitanya Kulkarni <chaitanyak@...dia.com>
To:     Yishai Hadas <yishaih@...dia.com>
CC:     "hch@....de" <hch@....de>,
        "alex.williamson@...hat.com" <alex.williamson@...hat.com>,
        "willy@...radead.org" <willy@...radead.org>,
        "akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
        "logang@...tatee.com" <logang@...tatee.com>,
        "axboe@...nel.dk" <axboe@...nel.dk>,
        Jason Gunthorpe <jgg@...dia.com>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "linux-block@...r.kernel.org" <linux-block@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Leon Romanovsky <leonro@...dia.com>,
        Maor Gottlieb <maorg@...dia.com>
Subject: Re: [PATCH V1] lib/scatterlist: Fix to calculate the last_pg properly

On 1/11/23 02:10, Yishai Hadas wrote:
> The last_pg is wrong, it is actually the first page of the last
> scatterlist element. To get the last page of the last scatterlist
> element we have to add prv->length. So it is checking mergability
> against the wrong page, Further, a SG element is not guaranteed to end
> on a page boundary, so we have to check the sub page location also for
> merge eligibility.
> 
> Fix the above by checking physical contiguity based on PFNs, compute the
> actual last page and then call pages_are_mergable().
> 
> Fixes: 1567b49d1a40 ("lib/scatterlist: add check when merging zone device pages")
> Reported-by: Jason Gunthorpe <jgg@...dia.com>
> Signed-off-by: Yishai Hadas <yishaih@...dia.com>
> ---

Looks good.

Reviewed-by: Chaitanya Kulkarni <kch@...dia.com>

-ck