linux-kernel - Re: [PATCH] zsmalloc: calling zs_map

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:   Wed, 20 Sep 2017 15:47:39 +0900
From:   Minchan Kim <minchan@...nel.org>
To:     Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        linux-kernel@...r.kernel.org,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>
Subject: Re: [PATCH] zsmalloc: calling zs_map_object() from irq is a bug

On Wed, Sep 20, 2017 at 03:39:41PM +0900, Sergey Senozhatsky wrote:
> Use BUG_ON(in_interrupt()) in zs_map_object(). Calling this
> function from IRQ is a bug, because we use per-CPU mappings
> and interrupt may corrupt those buffers.
> 
> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@...il.com>

IMHO, corruption the buffer would be not enough to be a BUG_ON
which stop the system fully so user loses any chances to shut
down smooth/hunt it down.

More serious thing of our case is that it can leak other user's
data by overwriting, which is more concern I am thinking now.

So,

Acked-by: Minchan Kim <minchan@...nel.org>

Thanks!