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Date:   Tue, 6 Jun 2023 19:21:12 +0300
From:   Tony Lindgren <tony@atomide.com>
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     Dan Carpenter <dan.carpenter@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        linux-serial@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] serial: core: don't kfree device managed data
Message-ID: <20230606162112.GM56720@atomide.com>
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 <20230606133749.GK56720@atomide.com>
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* Andy Shevchenko <andriy.shevchenko@linux.intel.com> [230606 14:54]:
> On Tue, Jun 06, 2023 at 04:37:49PM +0300, Tony Lindgren wrote:
> > * Andy Shevchenko <andriy.shevchenko@linux.intel.com> [230606 13:16]:
> > > On Tue, Jun 06, 2023 at 11:26:25AM +0300, Dan Carpenter wrote:
> > > > The put_device() function will call serial_base_ctrl_release() or
> > > > serial_base_port_release() so these kfrees() are a double free bug.
> 
> ...
> 
> > > These labels are also called without device being even added.
> > > So, this is not good enough as far as I can tell.
> > 
> > I guess you mean the possibe error returned from the call to
> > serial_base_device_init()?
> > 
> > If serial_base_device_init() fails, we return error and end up doing
> > the put_device().
> > 
> > We have serial_base_device_init() call device_initialize(), is that
> > not enough for put_device()?
> 
> It's not. The error is returned when device release callback is not assigned
> yet.

OK thanks for clarifying.

> And also just noticed since we return deferred probe, the message there should
> be ratelimited or given only _once().

We should be OK with debug here like Dan suggested.

Regards,

Tony