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From: Jason Gunthorpe <jgg@ziepe.ca>
To: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Cc: Jarkko Sakkinen <jarkko@kernel.org>,
	peterhuewe@gmx.de, p.rosenberger@kunbus.com,
	linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH] tpm: fix potential NULL pointer access in tpm_del_char_device()
Date: Fri, 24 Sep 2021 11:20:32 -0300	[thread overview]
Message-ID: <20210924142032.GY3544071@ziepe.ca> (raw)
In-Reply-To: <b49f4b52-44c4-8cb8-a102-689e9f788177@gmx.de>

On Fri, Sep 24, 2021 at 04:17:52PM +0200, Lino Sanfilippo wrote:
> On 24.09.21 at 15:33, Jason Gunthorpe wrote:
> > On Fri, Sep 24, 2021 at 03:29:46PM +0200, Lino Sanfilippo wrote:
> >
> >> So this bug is triggered when the bcm2835 drivers shutdown() function is called since this
> >> driver does something quite unusual: it unregisters the spi controller in its shutdown()
> >> handler.
> >
> > This seems wrong
> >
> > Jason
> >
> 
> 
> Unregistering the SPI controller during shutdown is only a side-effect of calling
> bcm2835_spi_remove() in the shutdown handler:
> 
> static void bcm2835_spi_shutdown(struct platform_device *pdev)
> {
> 	int ret;
> 
> 	ret = bcm2835_spi_remove(pdev);
> 	if (ret)
> 		dev_err(&pdev->dev, "failed to shutdown\n");
> }

That's wrong, the shutdown handler is only supposed to make the HW
stop doing DMA and interrupts so we can have a clean transition to
kexec/etc

It should not be manipulating other state.

Jason

  reply	other threads:[~2021-09-24 14:20 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-10 18:04 Lino Sanfilippo
2021-09-13 20:25 ` Jarkko Sakkinen
2021-09-13 20:53   ` Aw: " Lino Sanfilippo
2021-09-14  0:31     ` Jarkko Sakkinen
2021-09-24 13:29       ` Lino Sanfilippo
2021-09-24 13:33         ` Jason Gunthorpe
2021-09-24 14:17           ` Lino Sanfilippo
2021-09-24 14:20             ` Jason Gunthorpe [this message]
2021-09-29  8:58               ` Lino Sanfilippo

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