linux-kernel - Re: [PATCH v2 1/5] binfmt_elf_fdpic: Stop using dump

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 5 May 2020 12:48:05 +0200
From:   Christoph Hellwig <hch@....de>
To:     Jann Horn <jannh@...gle.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Christoph Hellwig <hch@....de>, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, linux-fsdevel@...r.kernel.org,
        Alexander Viro <viro@...iv.linux.org.uk>,
        "Eric W . Biederman" <ebiederm@...ssion.com>,
        Oleg Nesterov <oleg@...hat.com>,
        Russell King <linux@...linux.org.uk>,
        linux-arm-kernel@...ts.infradead.org,
        Mark Salter <msalter@...hat.com>,
        Aurelien Jacquiot <jacquiot.aurelien@...il.com>,
        linux-c6x-dev@...ux-c6x.org,
        Yoshinori Sato <ysato@...rs.sourceforge.jp>,
        Rich Felker <dalias@...c.org>, linux-sh@...r.kernel.org
Subject: Re: [PATCH v2 1/5] binfmt_elf_fdpic: Stop using dump_emit() on
 user pointers on !MMU

On Wed, Apr 29, 2020 at 11:49:50PM +0200, Jann Horn wrote:
> dump_emit() is for kernel pointers, and VMAs describe userspace memory.
> Let's be tidy here and avoid accessing userspace pointers under KERNEL_DS,
> even if it probably doesn't matter much on !MMU systems - especially given
> that it looks like we can just use the same get_dump_page() as on MMU if
> we move it out of the CONFIG_MMU block.

Looks sensible.  Did you get a chance to test this with a nommu setup?