linux-kernel - Re: [PATCH v8 08/10] drivers: qcom: rpmh: allow requests to be sent asynchronously

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: <CAD=FV=WmXkW1ms=4=25z=o7wt_uBZgS2t1SZr6qRLhP=B_bBMg@mail.gmail.com>
Date:   Fri, 11 May 2018 13:16:19 -0700
From:   Doug Anderson <dianders@...omium.org>
To:     Lina Iyer <ilina@...eaurora.org>
Cc:     Andy Gross <andy.gross@...aro.org>,
        David Brown <david.brown@...aro.org>,
        linux-arm-msm@...r.kernel.org,
        "open list:ARM/QUALCOMM SUPPORT" <linux-soc@...r.kernel.org>,
        Rajendra Nayak <rnayak@...eaurora.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Stephen Boyd <sboyd@...nel.org>,
        Evan Green <evgreen@...omium.org>,
        Matthias Kaehlcke <mka@...omium.org>, rplsssn@...eaurora.org
Subject: Re: [PATCH v8 08/10] drivers: qcom: rpmh: allow requests to be sent asynchronously

Hi,

On Wed, May 9, 2018 at 10:01 AM, Lina Iyer <ilina@...eaurora.org> wrote:
>  /**
> @@ -137,6 +140,8 @@ void rpmh_tx_done(const struct tcs_request *msg, int r)
>                 dev_err(rpm_msg->dev, "RPMH TX fail in msg addr=%#x, err=%d\n",
>                         rpm_msg->msg.cmds[0].addr, r);
>
> +       kfree(rpm_msg->free);
> +

The way the code is written makes it seem like you could free memory
_and_ have a completion but you can't.  Specifically:

* The only plausible thing that "rpm_msg->free" could point to is "rpm_msg".

* The complete(compl) would then be accessing freed memory.


I believe the kfree() should be at the end of the function.
Personally I'd make it more obvious that this is just a boolean value
and change to:

if (rpm_msg->needs_free)
  kgree(rpm_msg)

...then the reader of the code doesn't need to go figure out what
you're trying to free.


-Doug