linux-kernel - Re: [PATCH] iio: envelope-detector: fix use-after-free on device remove

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] [day] [month] [year] [list]

Message-ID: <CAGngYiXyEksuMDBkrasiwwge4fgoHKKecsSHB6q0GQyEoiZXxw@mail.gmail.com>
Date:   Mon, 11 Mar 2019 14:47:59 -0400
From:   Sven Van Asbroeck <thesven73@...il.com>
To:     Peter Rosin <peda@...ntia.se>
Cc:     Tomasz Duszynski <tduszyns@...il.com>,
        Jonathan Cameron <jic23@...nel.org>,
        Hartmut Knaack <knaack.h@....de>,
        Lars-Peter Clausen <lars@...afoo.de>,
        Peter Meerwald-Stadler <pmeerw@...erw.net>,
        "linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] iio: envelope-detector: fix use-after-free on device remove

Hi Peter,

On Mon, Mar 11, 2019 at 2:41 PM Peter Rosin <peda@...ntia.se> wrote:
>
> This is false positive, AFAICT. The delayed work must have
> finished while envelope_detector_read_raw() holds the read_lock
> mutex, and it would be highly surprising if the device can go
> away while it is handling an IIO ->read_raw call. (THAT would be
> an interesting bug...)

Quite right. I had completely overlooked the fact that wait_for_completion()
cannot finish unless explicitly completed. Unlike
wait_for_completion_interruptible().

So yes, this looks like a false positive. My apologies.

Sven