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Commit f9433449 authored by Lukas Wunner's avatar Lukas Wunner Committed by Greg Kroah-Hartman
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spi: spi-sh: Fix use-after-free on unbind 



commit e77df3eca12be4b17f13cf9f215cff248c57d98f upstream.

spi_sh_remove() accesses the driver's private data after calling
spi_unregister_master() even though that function releases the last
reference on the spi_master and thereby frees the private data.

Fix by switching over to the new devm_spi_alloc_master() helper which
keeps the private data accessible until the driver has unbound.

Fixes: 680c1305 ("spi/spi_sh: use spi_unregister_master instead of spi_master_put in remove path")
Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
Cc: <stable@vger.kernel.org> # v3.0+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation
Cc: <stable@vger.kernel.org> # v3.0+
Cc: Axel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/6d97628b536baf01d5e3e39db61108f84d44c8b2.1607286887.git.lukas@wunner.de


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 031ac028

drivers/spi/spi-sh.c

+4 −9
Original line number Diff line number Diff line
@@ -450,7 +450,7 @@ static int spi_sh_probe(struct platform_device *pdev) 
		return irq;

	}



	master = spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data));

	master = devm_spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data));

	if (master == NULL) {

		dev_err(&pdev->dev, "spi_alloc_master error.\n");

		return -ENOMEM;
@@ -468,16 +468,14 @@ static int spi_sh_probe(struct platform_device *pdev) 
		break;

	default:

		dev_err(&pdev->dev, "No support width\n");

		ret = -ENODEV;

		goto error1;

		return -ENODEV;

	}

	ss->irq = irq;

	ss->master = master;

	ss->addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));

	if (ss->addr == NULL) {

		dev_err(&pdev->dev, "ioremap error.\n");

		ret = -ENOMEM;

		goto error1;

		return -ENOMEM;

	}

	INIT_LIST_HEAD(&ss->queue);

	spin_lock_init(&ss->lock);
@@ -487,7 +485,7 @@ static int spi_sh_probe(struct platform_device *pdev) 
	ret = request_irq(irq, spi_sh_irq, 0, "spi_sh", ss);

	if (ret < 0) {

		dev_err(&pdev->dev, "request_irq error\n");

		goto error1;

		return ret;

	}



	master->num_chipselect = 2;
@@ -506,9 +504,6 @@ static int spi_sh_probe(struct platform_device *pdev) 


 error3:

	free_irq(irq, ss);

 error1:

	spi_master_put(master);



	return ret;

}