linux-kernel - Re: [RFC 0/3] iommu/iova: Unsafe locking in find

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, 3 Jul 2018 19:59:20 +0100
From:   Dmitry Safonov <0x7f454c46@...il.com>
To:     Dmitry Safonov <dima@...sta.com>
Cc:     open list <linux-kernel@...r.kernel.org>,
        David Woodhouse <dwmw2@...radead.org>,
        Joerg Roedel <joro@...tes.org>,
        iommu@...ts.linux-foundation.org
Subject: Re: [RFC 0/3] iommu/iova: Unsafe locking in find_iova()

Hi,

Any opinion on that?
It looks to remove a source of possible issues and
has a nice diffstat.

2018-06-21 19:08 GMT+01:00 Dmitry Safonov <dima@...sta.com>:
> find_iova() looks to be using a bad locking practice: it locks the
> returned iova only for the search time.
> And looking in code, the element can be removed from the tree and freed
> under rbtree lock. That happens during memory hot-unplug and cleanup on
> module removal.
> Here I cleanup users of the function and delete it.
>
> Dmitry Safonov (3):
>   iommu/iova: Find and split iova under rbtree's lock
>   iommu/iova: Make free_iova() atomic
>   iommu/iova: Remove find_iova()
>
>  drivers/iommu/intel-iommu.c | 14 +++----------
>  drivers/iommu/iova.c        | 48 +++++++++++++++++----------------------------
>  include/linux/iova.h        | 17 ++++------------
>  3 files changed, 25 insertions(+), 54 deletions(-)
>

Thanks,
             Dmitry