From: Alain Volmat <alain.volmat@foss.st.com>
To: Lukas Wunner <lukas@wunner.de>
Cc: <broonie@kernel.org>, <amelie.delaunay@foss.st.com>,
<mcoquelin.stm32@gmail.com>, <alexandre.torgue@foss.st.com>,
<linux-spi@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <fabrice.gasnier@foss.st.com>,
<antonio.borneo@foss.st.com>
Subject: Re: [PATCH] spi: stm32: drop devres version of spi_register_master
Date: Thu, 18 Mar 2021 08:22:38 +0100 [thread overview]
Message-ID: <20210318072238.GA10567@gnbcxd0016.gnb.st.com> (raw)
In-Reply-To: <20210316211744.GA25311@wunner.de>
Hi Lukas,
On Tue, Mar 16, 2021 at 10:17:44PM +0100, Lukas Wunner wrote:
> On Fri, Mar 12, 2021 at 11:34:46AM +0100, Alain Volmat wrote:
> > --- a/drivers/spi/spi-stm32.c
> > +++ b/drivers/spi/spi-stm32.c
> > @@ -1960,6 +1960,7 @@ static int stm32_spi_remove(struct platform_device *pdev)
> > struct spi_master *master = platform_get_drvdata(pdev);
> > struct stm32_spi *spi = spi_master_get_devdata(master);
> >
> > + spi_unregister_master(master);
> > spi->cfg->disable(spi);
> >
> > if (master->dma_tx)
>
> This introduces a use-after-free because spi_unregister_master()
> drops the last reference on the spi_master allocation (which includes
> the struct stm32_spi), causing it to be freed, yet the stm32_spi
> struct is accessed afterwards.
Indeed. Thanks. I've fixed that and will post it.
> You need to convert the driver to devm_spi_alloc_master() to
> fix the use-after-free. See commit 6cfd39e212de for an example.
>
> Thanks,
>
> Lukas
prev parent reply other threads:[~2021-03-18 7:23 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-12 10:34 [PATCH] spi: stm32: drop devres version of spi_register_master Alain Volmat
2021-03-12 20:25 ` Mark Brown
2021-03-16 21:17 ` Lukas Wunner
2021-03-18 7:22 ` Alain Volmat [this message]
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